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leigh
08-16-2002, 02:07 PM
http://leigh.cgcommunity.com/site_images/dummies.jpg
PHOTOREALISTIC TEXTURING FOR DUMMIES
Part 5
Specularity, Glossiness And Reflection

The Need For Some Shine

Okay, before the debate begins to rage as to whether or not to actually use specularity, or just stick to reflection mapping, let's first assess the necessity for shininess in the first place.
Basically, without shininess, an objects surface appears flat, and does not really "react" to the light shining on it (of course, the fact that it has a colour means that is it reacting in some way to the light, but I'm talking more in terms of visible "highlights"or "hotspots" here).

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureA.jpg
Figure A – without some kind of shininess this metal and the leather would appear extremely dull and flat.

Highlights on a surface give us an idea of how the surface feels – whether it is smooth or coarse (not in terms of the objects topography, which is generally defined by the bump map), whether it is hard or soft, dry or wet, old or new, greasy or slimy, and so on and so forth.

Another extremely important thing detail it relays to us is the objects everyday interaction with the world – by altering and breaking up the reflection of light on it's surface, we can get clues as to how the object is handled by people, or how it is used in the world. In other words, it shows us how the world and it's inhabitants have left their mark on it, so to speak. For instance, a wineglass is never really 100% squeaky clean – look closely at it, and you will see oily fingerprints, faint grime from general handling, smears from the last time it was washed, and an entire host of other greasy smudges, abrasions and dusty marks. These all affect the shininess of the object by lessening them. On the other hand, interactions can increase the shininess – for instance, an apple that has just been polished, will have brighter, shinier spots where it has been polished harder.

I think that we can all agree that the surface definitely does need some attribute to show the way in which these sort of things affect and wear an objects surface over time.

Finally, the most obvious need for this shininess is to show that the way in which local light-sources are affecting it. Of course, this is where the debate begins – does one use specularity, or reflection?

To add more substance to that question, here is a little refresher course on light:
As we all know, we are able to see things because of the way that light is reflected off things around us – the reflected rays shoot into our eyes, bounce around a complex setup of lenses and things inside our eyeballs, thus enabling us to see this wondrous world around us.
So, basically, when setting up textures in CG, we have to bear in mind that we are dealing with reflection of light, and therefore creating the "instructions" for how the light should be reflected off the objects surface by creating texture maps, right?
Every detail we see on a surface is there for us to see because light has bounced off it and into our eyes, showing us what the surface looks like.

To sum it all up – shininess is the reflection of light – the stronger the reflection, the shinier the object.

So, how do we set that up?
This brings us back to the question – do we set this up using specularity? Or reflection??

To fully illustrate both sides of this question, let's look a little more closely at these two options…

Specularity – The Big Fake

Okay, so what exactly is specularity?? In reality, the effect known as specularity in CG is actually called specular reflection. A dictionary definition would describe specular as a "mirror-like quality".
However, unlike it's real-life equivalent, the effect of specularity in it's 3D package incarnation, as we are familiar with, is actually quite different from the reflection option in any surface editor.
Specularity is basically a way of faking the reflection of light on the objects surface.
Let me explain.
Technically speaking, when you see a highlight on an objects surface, it is actually a reflection of all local light-sources. For instance, if you place a fairly shiny plastic cup onto a table in a room that is lit by a single lightbulb, you will notice highlights all along the surface of the cup (and the table too, obviously, but we are concentrating on the cup in this particular example). Now, if you look really, really, really closely at these highlights, you will discover that in actual fact they are reflections of the lightbulb itself.
Obviously lots of surfaces don't have very tight, defined hotspots which are as clear as they would be on a plastic cup, but all that has happened is that the reflection has become more spread-out, a property which is controlled by the gloss amount, which will discussed a little later on.
So, having said that, you may be wondering why I said that specularity is fake.
Specularity is fake because it doesn't actually reflect the light-source in the same way that the surface would in reality, instead it just gives the illusion that the surface is reflecting light.
In other words, it shows highlights simply because there is light shining on it. It isn't actually reflecting anything as such. You could, for instance, shine a spotlight onto the object, and when it renders, you will see a round hotspot on the surface, not an actual reflection of the spotlight itself.
Basically, specularity gives you round hotspots, that you can break up a bit using specular maps.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureB.jpg
Figure B – Specularity creates round hotspots on your surfaces.

Reflection – The Real Deal

Fake not good enough for you? Well, reflection is pretty self-explanatory. Using reflection on the surface will obviously allow the object to reflect its surroundings and local light-sources correctly. No need for any in-depth explanations here, as we are all aware of what reflection is and what it looks like.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureC.jpg
Figure C – Using reflection allows the surface to reflect its surroundings like a mirror.

leigh
08-16-2002, 02:10 PM
The Big Showdown – Specularity VS Reflection

Right, now that we understand what specularity is and what reflection is, we can look at the argument as to whether to employ one or both in a surface.

Why use specularity if it is fake?

A fair question. I guess there are 2 immediate answers to that question:

Firstly, specularity renders faster than reflection. Accurate reflections require complex raytracing which takes a lot longer to render that specularity. In order to utilise reflection in most software, one has to activate a reflection option in the rendering settings, which adds time to the render in order to calculate the reflections. And we all hate waiting for renders.

Secondly, reflection almost always makes objects begin to appear mirror-like. To go back to our earlier example of a plastic cup, if I want to make a plastic cup that should be realistic, using reflection instead of specularity is more than likely going to make the cup look unnecessarily mirror-like.
Perhaps plastic isn't the best example here, as it usually is a bit reflective as well as shiny, so let me give another example – wood. Wood that has no varnish on it, and is fairly dull, and really doesn't appear reflective at all, will nevertheless have a hotspot (however faint and spread-out it might be) on it if you shine a light directly onto it. Giving the wooden surface a certain amount of specularity will allow this hotspot to show on the surface without it reflecting like a mirror, which is what would happen were you to use reflection instead.
The same goes for cloth. Look at the clothes you are wearing – light is creating highlights on your clothes – these highlights are especially noticeable on folds in the fabric, where it is catching the light. Fabric, however, is most certainly not reflective in the sense of reflecting objects around it. So using specularity instead of reflection in this case is more feasible too.

All this is rather mind boggling when you consider the fact that the reason that objects appear shiny in the first place is because they are, technically, reflecting light.
So even fabric is technically reflecting light. So is dull wood. It's just that using reflection is CG tends to makes these surfaces look too mirror-like.

On the other hand, if you are wanting to recreate reality perfectly, then it would make sense to use reflection, as this is the physically correct method.

AAAARRRRGGGHHH!!!!
So, which one do you use????

I guess this is the bit where I am going to tell you to use basically whatever you think looks good. This argument can go on and on, but in the end I always think that if it looks good, use it.

Yes, reflection IS the more realistic way of doing it, in terms of physics. That is easy enough to understand. It's just that, more often than not, the results of doing it like this tend to end up looking wrong.

What do I use? I tend to use a little bit of both. I have always used specularity, and I use reflection to enhance my specularity. However, I have seen some great work done without any specularity whatsoever. I guess it really comes down to individual methods of doing things.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureD.jpg
Figure D – our trusty sphere with both specularity and reflection applied.

Having said all this, the cool thing is that making maps for specularity and reflection is exactly the same, as they are logically doing the same thing – defining the shiny areas.

So, how about some tips for working with this stuff?

Here are some useful tips and trivia for making specularity and reflection maps, and working with these attributes when texturing:

Variation! No surface in reality has a perfect, consistent shininess. Everything has been touched in some way by something – whether by people, animals, the weather, or anything else. These things will leave fingerprints, smudges, scratches and other artefacts that will lessen the shininess of the objects surface. It is important to include details like this, as even if they may be really small and almost indistinguishable, they are nevertheless essential details for realistic real-world surfaces.

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Show some weathering. The weather, as I mentioned above, leaves obvious marking on surfaces. These sorts of marks include drips, stains, drying, damp and that sort of thing on items. Remember that this sort of damage should also be included in your colour and diffuse maps, and are further enhanced by including them into your specularity/reflection maps as well.
For instance, the paint on a house will, over years, begin to show weathering from rain and sun – in terms of damp gathering in corners, streaky drips down walls, and drying out and cracking where it has been faced by too many hours in the sun. Obviously these details will go into the afore-mentioned colour and diffusion maps, but altering the specular/reflection maps will add more detail to these effects – in terms of the dried, flaky paint will have a broader, less strong shine too it than areas which are in constant shadow, and have become damp.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureE.jpg
Figure E – add some variation and weathering to your reflection and specularity.

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For human skin - Look carefully at a face. Notice how the shininess of skin is uneven. A classic example of how shininess differs in skin is to look at the area of skin where the nostril meets the cheek on the face. Almost always, the skin in this area is drier and ever-so-slightly rougher, causing it to be a lot duller than the cheek. The tip of the nose is almost always rather shiny too.
If you have any scars, you will see that scar tissue is much shinier and more reflective than normal skin too. Also look closely into the wrinkles on the joints on your fingers, and you will see that the skin there is smoother and shinier. Also, on the fingers, the bit of skin just above the cuticles and along the sides of the fingertips tends to be very shiny and smooth.
If you are texturing skin that has any tattoos on it, you should note that tattooed skin is also much shinier, as it is technically also scar tissue.

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Surfaces that are scratched – remember that with abrasions and scratches, the shininess tends to change. For instance, if you have a piece of metal that is painted, the paint will have a certain shininess. But where there are scratches in the paint, the metal beneath will show through, and the metal will have a different shininess to the paint.

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Basic human interaction with objects leaves very specific and identifiable marks – particularly from fingerprints. Our fingertips are very oily, and tend to leave visible residue on everything we touch. For example, if you handle a wine glass, you will definitely leave fingerprints on it, that will alter the reflections in the glass – in other words, where the fingerprints are, you will not see as much reflection as in the untouched areas.

:lightbulb Tip: An easy way of adding these to your maps is to make a bunch of custom brushes in Photoshop, which are the shape of fingerprints. You can make prints from your own fingers and scan them in, make selections from them and define brushes from those selections so that you can literally just paint fingerprints onto your maps. Be sure to have a couple of different ones though, of varying sizes and patterns, for added realism.

Another example of how human interaction alters surfaces is to look at things that have been used frequently, such as your computer mouse. Look at the buttons of your mouse – years of clicking away at them tends to wear the plastic down so that it is smoother, and very slightly shinier, since your fingers have essentially been polishing this area (unless, of course, you haven't cleaned your mouse recently, and instead of it being smoother and shinier, it's just a bit grimy, in which case the shininess would actually be less).
When dealing with specularity and reflection, it's extremely important to have a good understanding of where the object has been, and how it is used.
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leigh
08-16-2002, 02:18 PM
Blur your reflections – if your software has the option of blurred reflections, for heavens sake use it! Unless you are texturing a perfectly clean mirror, most reflective surfaces have a certain degree of blurring to them. Even just slight blurring can help to get rid of that nasty CG look.

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Specular blooms – blooming is basically an effect from very, very bright highlights, where the highlight almost seems to glow. This is very noticeable on things that have been covered in some sort of lacquer – such as car paint. The finish on car paint often tends to give off extremely bright highlights when the car is in the sun. Looking at these spots usually gives you mild retina-burn – I'm sure you all know the effect I'm talking about. It's almost like a mini-lensflare, in that it is sparkly, and has lots of little streaks coming out of it. Most software has some kind of bloom effect, in the form of an extra shader, or specular parameter. If you are working with surfaces that are coated in very reflective substances, then adding a bloom can give it a nice touch.

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The Fresnel Effect – in the reality, the angle between you and the surface of the object that you are looking at affects the amount of light that is reflected and refracted that you can see. This effect is particularly important when dealing with surfaces which are transparent.
For example, if you look at a lake from a far-off distance, it will appear almost completely mirror-like, yet, as you get closer, and the angle at which you are seeing the water widens, the water appears less reflective and more transparent. This is called the Fresnel Effect (pronounced "fre-nel" – the "s" is silent), an effect wich gets its name from the French physicist Augustin-Jean Fresnel, who first documented it.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureF.jpg
Figure F – the Fresnel effect in action. As the sphere curves away from the glancing angle, the reflectivity of the surfaces increases.

You can implement this effect in one of two ways:

Firstly, by using a Fresnel shader (such as the one that comes with Lightwave). The shader pretty much creates the effect for you, just leaving you to adjust it the way you want. A Fresnel shaders effect is generally controlled by adjusting the glancing angle for the specular, reflection and transparency amounts (some shaders offer controls for other attributes such as luminosity, diffuse, and translucency as well, but these are, in my opinion, better controlled by gradients).
The glancing angle is measured from the surface normal, thus 0 degrees is any surface normal that points directly at the camera, and 90 degrees refers to any surface normal that is perpendicular to the camera.
So basically, you set the minimum glancing angle and enter in the amount of reflection, specularity and transparency that will be visible at that angle (generally speaking, the lower the angle, the lower the amount of reflection, and the higher the amount of transparency, if the object is transparent), and as the angle increases, the amount of reflectivity will increase.

The second way of creating the Fresnel effect is by faking it with gradients (ramps). Basically, this involves putting gradients into your reflection channel (as well as a gradient of opposing values into your transparency channel, if the object is transparent), that are controlled by incidence angles.
In other words, you create an incidence-angle gradient going straight from dark to light, and you put it into your reflection and specular channels, so that when you look straight at the object, it isn't reflective, but as the surface slopes away from you, it becomes shinier and more reflective.

Let's say, for instance that I am texturing a chrome sphere (and for the sake of this example, let us assume that this chrome sphere is absolutely perfect in terms of being perfectly 100% reflective).
I would place an incidence-angle gradient into its reflection channel, going from 100% black to 100% white.
The effect that this gradient will have is basically 0% reflection when looking perfectly level at the object (0 degrees glancing angle), going to 100% reflective at any part of the object that is viewed at an angle of 90 degrees from the same point – in other words, the front bit of the sphere that I am looking straight at will appear absolutely 0% reflective, while the very edges of it will be 100% reflective.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureG.jpg
Figure G – a light incidence gradient that will be 0% reflective at a glancing angle of 0 degrees, and 100% reflective at an angle of 90 degrees.

The same technique would apply for a transparent bubble. Now that you understand the basic principle of the Fresnel effect, you should know that if you were to create a bubble floating in the air, if you point a camera straight at it, the bit facing directly level at the camera would appear more transparent than the edges, which would ideally appear more reflective.
This effect would be achieved by placing gradients of opposing values into the reflection and transparency channels.
In other words, you would place a gradient going from black to white (as in the previous example) into the reflection channel, so that the reflection would be 0% when looking at it straight on. Then, you would place a gradient into the transparency channel that goes from white to black, so that where it is 0% reflective, the bubble will be 100% transparent, and where it is 100% reflective, it will appear 0% transparent. Make sense? Good!

Remember that this is actually a real world effect, so you should try and utilise it.

:lightbulb Tip: Gradients/Ramps are really excellent things to use in texturing. All too often their usefulness is overlooked, when in fact they are absolutely essential for creating certain effects, such as I have explained here. They are also great to use as alpha channels for image maps or procedurals that you may also be using. I highly recommend checking out how the application you use implements them, and start using them! You will most likely find them invaluable once you see how incredibly useful they are, especially for controlling the visibility and placement of other maps and effects in multi-layer texturing.

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BRDF – aaah, the most impressively named effect in texturing - the bi-directional reflectance distribution function. Complicated sounding name, fairly simple effect (in terms of execution). It is generally implemented into 3D software as an extra shader. I'm not sure which applications apart from Lightwave have this function, so I will leave it up to you to find that out.

For people who like to sound like physicists, here is an extremely technical explanation of BRDF for you to try and memorise:
The bi-directional reflectance distribution function gives the reflectance of a target as a function of illumination geometry and viewing geometry. The BRDF depends on wavelength and is determined by the structural and optical properties of the surface, such as shadow-casting, mutiple scattering, mutual shadowing, transmission, reflection, absorption and emission by surface elements, facet orientation distribution and facet density.

Hmmm…. That didn't make a whole lot of sense to me.

Simply put, BRDF basically describes what we all observe every day - that the surfaces of objects look different when viewed from different angles, and when illuminated from different directions. It's to do with the directional scattering of lightrays from an objects surface (as well as the bouncing of light within an object, known as sub-surface scattering, which is something that I will deal with at a later stage, when I do the workshop on Translucency).

Not to be confused with the Fresnel effect, as this is quite different, the implementation of BDRF in 3D software is basically to add detail to the specularity – it allows for the effect of anisotropic specular reflection.
Anisotropic specularity is basically specularity with a grain in it. A distortion. It can be used to create what is often called a "brushed-metal" look.
Basically what it does it create the illusion of tiny grooves on the surface, which then reflect the light in different directions, depending on the way in which the grooves run along the surface. You can also use the shader to determine which lights affect the surface, and are thereby scattered by these grooves. This results in a broader, softer specular highlight (as in Figure H).

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureH.jpg
Figure H – BRDF shader with anisotropic specularity.

Another thing that (LWs) BDRF shader does is allow you to add multiple layers of specularity. This is really awesome for when you are texturing something that is coated with varnish or any other lacquer. For instance, if you are texturing a car – a cars surface is covered in paint, which is then coated in a clear seal. These two substances (the paint and the coating) each have a different specular amount, which you can use this shader to set. Pretty nifty.

http://leigh.cgcommunity.com/site_images/dummies/part_5/figureI.jpg
Figure I – BRDF shader with 2 levels of specularity. The lower layer has a tighter highlight while the top layer has a broader highlight.

leigh
08-16-2002, 02:21 PM
Lastly, the most important tip of all – DON'T OVERDO IT!! One of the worst mistakes made in texturing is the tendency of individuals (especially beginners) to completely overdo reflection, and make everything look perfectly mirrorlike. This is a dead giveaway that the object if computer generated. Apart from that, it also looks a bit yucky. So just use it in moderation – study your references for the object you are texturing, and make sure that it's reflection/specularity matches. You will see that cars in the real world are not 100% reflective, and neither are chrome teapots (although those are very reflective, just not 100%).

Ummm… wasn't this workshop also supposed to be about Gloss??

Well, I left glossiness to until the end because there isn't all the much to explain - basically, the gloss amount in your surface editor controls how spread out the specular highlights are. The higher the gloss amount, the tighter the highlights.
For example plastic tends to have a fairly high glossiness, whereas fabric such as cotton has practically no glossiness. Pretty simple.
Usually you have to have some amount of specularity on a surface to use glossiness, or else the gloss amount won't actually have any effect, because it works hand-in-hand with specularity.
And that's about it!

dark_lotus
08-16-2002, 04:05 PM
Leigh dis is das butiful darlink.

HapZungLam
08-16-2002, 04:15 PM
Leigh, these tutorials really helped me upgradeing my texture skills.

okay, now let me start reading your lesson 5

Jaspar
08-16-2002, 04:39 PM
Nice one Leigh!
Gotta read them all when I have time, they look great!:thumbsup:

l_farley13_l
08-16-2002, 04:48 PM
An aweful lot of good stuff in there, hope we see fewer and fewer mistakes (car paint hmm), and people take the time to read through. You could also mention the diferent lighting meathods (blinn, phong etc.) use the spec slightly diferently. Diff applications.

Thanks for taking the time,

Farley13

d_hansbury
08-16-2002, 04:51 PM
Leigh's tutorials made me realize that max is horrible for realistic texturing after trying in vain to create them for a while.
I'm in the process of learning lightwave...maybe one day I'll post some completed work.

Thanks for your knowledge.

road
08-16-2002, 05:49 PM
d_hansbury....
what are you talking about????
Max has one of the best material editors!!!

Sevarf2
08-16-2002, 06:03 PM
Yes, Max has a good material editor, the problem is the rendering engine (but with the help of some GI re and with the 5 release...)
Leigh: good work. You helped more peoples (included me)
I can't wait to see the Wiro's model finished.

HapZungLam
08-16-2002, 07:25 PM
finally finished reading this lesson. there has a couple of question that i wanta make myself clear.

You discripe mostly how specular/reflection works and do, but you never tip us how to create a spec/reflection map.

Most of the time, when i put a spec map for a human face. it always over spec, super shinny. How do i reduse it. what is generally the amount of spec does skin has?

another example "wood", it does reflect as you said, it look dull is because maybe the reflect area is being spread? so, how am i going to applying using spec/reflect map?

Finger prints. Basically everything has being touched, so should i add finger prints on every object? everywhere around the object?

How do i add finger prints as a spec channel/map?, has finger prints on meaning not as spec/reflect as the others? or? the otherway around?

boomji
08-16-2002, 07:48 PM
hey dudesss !!!
every time i read/hear your name i think of the intro(promo) to starcraft.
i'll explain why.
the first workshop you did you got haraungued for the procedural vibe.there was so much cross fire i thaught cgtalk was going to catch fire :). everytime somebody bombed you defended like the sunno'f a leo you are :thumbsup: it was like one of the cut scenes of star craft where all the guys in the siuts were dismembered one by one and there was utter kayos and firing every where.the aliens/zergs getting closer and all around...hehe
youre the last one standing them off untilll...
atta girl.like i said(or have i) this version shows you've grown from every previous installment.bellissima !!!
b

Goon
08-16-2002, 08:02 PM
Leigh; you are awesome!
thanks a bunch!!! :buttrock: :buttrock: :buttrock:

BUT... i gotta go against you on the finger print thing. i'm sitting in my cubicle bored as hell, and the only things that i can leave noticeable prints on are the computer screen and glass. it seems like anything with a very smooh and reflective surface will have its properties noticeably affected by the oil from the hands but anything with a noticeable diffuse because of surface roughness is already disrupting the reflection/specular distribution enough that any fingerprint becomes invisible. Really sweaty hands will leave a more specular surface, but other than that, its hard to find fingerprints.

dwkim
08-17-2002, 12:27 AM
Not to nitpick, but one thing could be cleared up about reflections.
While "100% accurate" reflections may require raytracing, some software can render reflection maps on the fly. For example, ElectricImage can render cubic and planar (mirror) reflection maps during rendering, and renderers such as Renderman, Entropy, Air, RenderdotC, etc. can be used to render planar and cubic environments as well through writing scripts or using rib generators such as Mayaman, Softman, MTOR, etc. These reflection maps can also use z-depth buffers to add a DOF to the render to give effects like sharper reflections for closer objects, fuzzier for further away objects. I suppose you could even do things such as highly saturated for close up, desaturated for further away and any other freakishly anal-retentive post processing on environment maps that you may need or want.

While these rendered environment maps will render "accurate" reflections of the environment, self-reflections are not accurate and can have some problems, unnoticable by most viewers. If self reflections need to be accurate, a combination of using rendered environment maps and raytracing could be done to not have to raytrace the entire scene.

Just thought I'd note this to generalize to a larger variety of software. Hope you don't mind.

Aura
08-17-2002, 04:29 AM
Oh,leigh princess,they are really helpful.
Thanx and i start reading it now....:applause:

wgreenlee1
08-17-2002, 04:46 AM
:eek: Leigh is truly the Texture Goddess.......:wavey: :thumbsup:

Hookflash
08-17-2002, 04:57 AM
Wow!!! I just found out about Leigh's texture workshop threads today, and I'm very, very happy & greatful. Texturing has always been difficult for me, but I can tell these tutorials are going to clear things up. Thanks a million Leigh:) :buttrock: :bounce:

CitizenVertex
08-17-2002, 06:08 AM
This explanation of specularity vs reflection is pretty poor. Because of a misconception about specularity, the "tutorial" is fundamentally flawed. There is a deffinitive difference between reflection and specualrity. I don't understand why there would be an argument about using one or the other as they both simulate different things. Specularity is the area of surface where light is being scattered at a narrow angle. Light of course is "reflected" in a general sense, but it is not a true reflection. Specularity allows you to vary the angle at which light is reflected creating a hotspot of the surface. It is not a reflection of the physical lightsource or a true reflection. It is just a general reflection of light. What raytrace reflections or reflection maps in CG are attempting to recreate are specificly are true mirror reflections. Where light hits the surface and is reflected at an equal angle. There is nothing "fake" about specularity in 3D as it is approximating a different attribute of a surface than a true reflection. Of course if you have a shiny, highly polshed, reflective surface, you are going to want to, and in fact NEED to use both properties.

Galo
08-17-2002, 10:59 AM
YEAH that's it, i was waiting for that one :D

Marcel
08-17-2002, 02:04 PM
Leigh, again a great tutorial!
I have only one little point of critique: the images of the materials are way too small, I really can't see what's going on there....

CitizenVertex wrote:
There is a deffinitive difference between reflection and specualrity

You are wrong about that. A specular reflection is basicly a fake blurred reflection. The following image is a very good illustration of this:

http://members.rott.chello.nl/mvijfwinkel/ss_dof.jpg

(This is not my work. I've also cropped the image and put it on my own webspace. The original image is in this thread: http://www.cgtalk.com/showthread.php?s=&threadid=7379)

The specular highlight on the plastic network cable is not made with a specular reflection but a blurred 'real' reflection of the enviroment (and a so called white card hanging above the object).
Look at the reflections in the metal, it is reflecting the same objects only it's a sharp reflection instead of a blurred one.

Of course if you have a shiny, highly polshed, reflective surface, you are going to want to, and in fact NEED to use both properties.

You really don't, look at the following image, the car paint has 0% specularity and 0% gloss:

http://members.rott.chello.nl/mvijfwinkel/viper_sun.jpg

The highlight you see on the carpaint is not a specular highlight, but the real reflection of an object in the scene acting as the sun.
In real life, every highlight on a object comes from a real lightsource, and is in fact a real reflection. (a sharp or a blurred/scattered one).

Specular reflections are 'fake'. If I had the choice I would use blurred real reflections, which look nicer in my opinion. Like Leigh said, a specular reflection doesn't mimic the shape of the lightsource. A specular reflection of a window still gives a round highlight, not a rectangular shaped one.
Sadly, the computers just aren't fast enough for that to be possible (maybe for simple stills, but not for complex objects and animations).

Leigh, one thing I think is missing in this tutorial is an explanation of the importance of the enviroment that is being reflected
A short explanation how High Dynamic Range images work would also be a valuable addition, since lots of people use these to beef up their reflections.

PhilOsirus
08-17-2002, 05:30 PM
This is cool! There should be more workshops like this. With all the pros visiting this site, it would be could if they could just show us how they modeled their latest character or vehicle. No need to make it a tutorial, just show us how you proceeded:) I hope other will take part in this.

Grooveholmes
08-18-2002, 04:57 AM
I've got to agree with CitezenVertex on this one.

NanoGator
08-18-2002, 07:44 AM
Originally posted by Grooveholmes
I've got to agree with CitezenVertex on this one.

I wouldn't recommend that. He did not provide a devastating blow to Leigh's post. She is right.

CitizenVertex 's half right about specularity. What he's half wrong about is a combination of things: How specularity is generally used, and how specularity is not being properly treated in LW.

In real world photography, specualrity IS very different from reflections and is treated differently. Photographers put polarizers on their cameras in order to filter out specularity sometimes. However, a polarizer cannot filter out reflections. Photographers take advantage of specularity in order to add depth to an image, or they filter it out to reveal details underneath it. It all kind of depends on what the aim of the photo is.

Lightwave has a very interesting feature: You can tell lights not to cast specular or diffuse reflections. This can be used to simulate the polarizer on a photographer's lens. I frequently make clones of the key lights. The first clone has specularity disabled, the second clone has diffuse disabled. One light controls the specularity, and the other controls the diffuse. If I don't want the object to have lots of highlights, I just turn the specularity light down.

I mentioned earlier that CitizenVertex was only half right. Maybe that wasn't quite the proper way to phrase it. I was measuring the tone of his post more than the details of it. The problem is that most people (at least that I've seen elsewhere, Im new to CGTalk. My opinion is not based on work I've seen here..) don't use specularity properly. They may get nice results, but I'm not convinced that they are fully aware of what they're doing with it. It is basically assumed that specularity makes something shiny. Which is fine, it does that. However, the circumstances of that shine (as I mentioned above) are in control of the photographer. You have to know when you want the highlight to reflect the light source or when you want the specular highlight to come up.

Starships come to mind as I write this. Star Trek in particular. Sometimes a starship looks really shiny, sometimes that same ship looks dull and rough. This happens for the reasons I mentioned above when the models are being filmed. Photographer's choice. But when I see ameteur models of these ships, they either have specularity turned on, or they have it turned off. They don't realize that there is a nice inbetween they could take if they took the time to tweak it.

It's for this reason that I think Leigh is right. For the intents and purposes of the people making use of this tutorial, her point is very valid. Specularity is fake. Unless they realize that specularity works the way CitizenVertex described, it is not being used that way at all. People use it to simlulate exactly what Leigh described with the car. For that case, what Leigh is saying is very important, and gives people a much better understanding of what it's all about. If you think of specularity as fake, then you understand what it is you need it to do and THEN get the results you need.

I mentioned that LW's interpretation of specularity is wrong. The problem with specularity is that it doesn't take into account the size of the light, or the incidence angle. Fortunately, LW lets you fix this. You can use area lights to fix the shape of the specularity, and you can use the fast Frensel plugin that Leigh suggested earlier to fix the incidence problem. However, in the case of light up signs and so on, you really need a texture to do that. Bing bing! Reflections come in. You can do with reflections what you cannot do with specularity. That's why what's being said in this thread is extremely valuable.

CitizenVertex was definitely right that there is room for both. However, it does not detract from what Leigh is saying.

NanoGator
08-19-2002, 07:05 AM
Heh I hope somebody read that, I feel like I killed the thread.

psil
08-19-2002, 08:23 AM
i read you, Nano - very interesting. I'm no physicist so I can't comment, BUT remember these tuts are 'Photorealism for Dummies' (not physicists) - tricky stuff explained in nice clear English. Speaking as a dummy, I think they do a damn good job:thumbsup:

What might be useful is more practical info on how to create the custom texture maps that Leigh constantly recommends. Specific PS tools, resolution, blending modes, how to paint out shadows and highlights fom photos etc. It's hard to find good info on this stuff, 3D texture-wise.

frog
08-19-2002, 09:17 AM
Originally posted by CitizenVertex
It is not a reflection of the physical lightsource or a true reflection

You are wrong, I'm afraid. Check this article (http://www.neilblevins.com/cg_education/metal_and_refs/metal_and_refs.htm) by Neil Blevins.

Also, re polarisers: reflections are exactly what polarisers cut out, specular reflections from materials like water. Photographers often use polarisers to cut down reflections on water or glass. Check this link (http://www.aaacamera.com/circular_polarizing_filter.html) to see a demonstration of how a polariser cuts out reflections on glass.

IMO the specular properties of shiny materials are much better controlled by refection of real lightsources rather than using specularity. Those plain round highlights are one of the main reasons that so much CG makes the world look as if everything is made of plastic :)

playmesumch00ns
08-19-2002, 10:49 AM
just to add my two cents to the argument:

Back in the early days (long before I even knew what CG was), the lambertian model of shading was the first to be used, because it was simple, fast and based on empirical observations of "rough-ish" surfaces. For those of you who are mathematically minded, the amount of illumination is proportional to the cosine of the incidence angle and the surface normal. This is called the diffuse model of reflection as it deals with surfaces that diffuse incoming light as the rays are scattered in all directions by microscopic surface irregularities. This is like the Lambert shader in Maya

Now that's fine for rough-ish surfaces, but what about smooth surfaces? A perfectly smooth surface will reflect a perfect "image" of the light source. That means that for a perfectly smooth sphere illuminated by a single light, you will only be able to see the sphere when the angle of incidence of the incoming light equals the angle reflection of the reflected light from the surface, i.e. when the light is bouncing off the sphere straight into your eyes, otherwise the sphere will be black. There are several functions for the calculation of the falloff of the specular highlight (the reflection of the light source), the two most common being the hook and blinn functions. What these functions all do is describe the falloff from the specular highlight colour to black around the point on the surface when the light relection vector and the viewing vector coincide, thus giving a round highlight.
This is the specular model of reflection and is something like the metal shader in 3dsmax

So now we have reflection models for perfectly smooth and fairly rough surfaces, but as we well know in real life things are usually somewhere in between the two. So these two are additively combined (along with ambient reflection) to make the Phong illumination model, which allows you to have diffuse light reflection and a specular highlight! woohoo! joy to the world!

But - as has been pointed out - specularity, as described in CG models, is a fake. What we should see is a reflection of the light source, not a round highlight. The reason we can usually fake it as such is that no surfaces are perfectly smooth. We do not expect to see a perfect image of the light source unless we are looking in a mirror. So a bright smudge will do just fine for most applications.

So if we want a more realistic highlight then we just use no specular reflection and raytrace instead. But, as (i think) Leigh neglected to mention, we must then include some geometry to represent the light source.

If we don't want a perfectly smooth surface then we have to use a blurred reflection function (which adds to our render time).

As with all things in CG, we have to compromise and the fake is usually sufficient. There's no point raytracing with blurred reflections to simulate the specular highlights on a character's face for example. Although the end result would be realistic, I doubt you'd be able to do enough test renders to get it looking right before you'd died of old age.

As Leigh said, correct use of specularity is vital in conveying a sense of "smooth" or "rough" surfaces. Smooth surfaces look smooth, not because they are reflecting "more" light, but because they are reflecting more light straight at us (provided we are looking at them from the right angle).
I won't get in to sub-surface scattering, suffice to say it's effect is like diffuse reflection, only more so

leigh
08-19-2002, 01:32 PM
Wow, I get back from the weekend to find loads of replies here, my PM inbox flooded, and my email straining from all the response :D
Thanks for all the ocntributions and debate so far people - this is what it's all about!!

dark_lotus, Canofworms, l_farley13_l, d_hansbury, Sevarf2, Aura, wgreenlee1, Hookflash, Phil "Osirus" - thanks for all the postive and encouraging comments :thumbsup:

HapZungLam - I will be putting together a bit on painting specularity and reflection maps as soon as I have a bit more spare time again. In the meantime, just read the tips that I put together, and see what you can use from that.
The overall amount of spec that skin has is tricky to say. What I always do is make a spec map using shades of grey, load it into my spec channel, and then just adjust the spec amount until it looks right.
For wood (and anything else actually), I tend to always use combinations of both reflection and specularity. As I said, I find that I, personally, get the bets results when I use both.
Fingerprints - nah, you don't have to go and put them onto absolutely everything. However, I do find that for things like glass, it looks great. I know that in reality everything we touch does get fingerprints on it, but I guess most substances absorb the oil from the prints, so that they are no longer as visible.
To add fingerprints to your spec and ref maps, just paint them onto the maps - as I explained, the best way to do that is to make brushes in Photoshop that look like fingerprints. Then you paint them on, making those areas darker.

road - Max's material editor is pretty cool, yeah, but for best results, it's advisable, in my opinion, to use the raytrace materials - they allow more options, and give you greater control in terms of setting up surfaces which act the way they should in the real world.

boomji - hehehe what a funny story! I love that intro! And yeah, I'm a true Leo to the end... :p

Goon - as I explained above to HapZungLam, fingerprints are great, but indeed are unnecessary unless it's for glass. Looking at my computer monitor, I see that although it has been recently cleaned, there are still oily smudges and fingerprints on it, so if I were to make a CG computer monitor, I would most certainly add the fingerprints to the texture. Something else that would work very well in conjunction with the fingerprints would be to use some gradients along with them to give that oily array of colours when you see the fingerprints from some angles. Now THAT would look cool....
But yeah, with most other surfaces, the fingerprints do disappear rather quickly, so it's mostly unneccesary to put them there. Unless you are a real detail freak...

dwkim - thanks for that info on rendering. I do know about some of that stuff that you mentioned, but I thought not to include it because I didn't want to confuse the texturing issue with the rendering issue at this point - because I wasn't writing about reflection environments, just reflection maps for the objects reflection channel. However, I am glad that you did post all that so that people can find that out once they have read the actual workshop :)

CitizenVertex (and also Galo and Grooveholmes)- I knew that this debate would start, it was one of the reasons why I posted this in the first place. The whole specularity VS reflection debate is a fascinating one, which is why I posted both sides of the equation and left it up to the readers to experiment and decide for themselves which methods work for them.
"Specularity allows you to vary the angle at which light is reflected creating a hotspot of the surface." - yeah, that is why I mentioned anisotropic specularity, because that is the function you use for altering the angle.
I do disagree with you on the point of specularity being a reflection of light in general though. There is no such thing as "a general reflection of light" - the light came from somewhere, the lighsource, so it would stand to reason that the reflection is therefore always of the source, however distorted or blurred it may be.
Like I said, I personally find that a combination of the two gets great results, but I do believe that specularity in its 3D incarnation is, technically speaking, a fake.
Specularity, in this sense, does not actually exist in the real world - it is a phenonmenon of artistic recreation of objects. As I explained, the term specularity refers to specular highlights, which are actually reflections of the lightsource. Therefore, it's logical that there would be a debate as to the use of specularity in CG, when in terms of reality, reflection is the one that should be used.
However, as far as I am concerned, because all of CG is a big fake, I don't see why I can't use specularity - if it looks right, then I use it. And 99.9% of the time, I find that using specularity does give me the look I am after, so I use it.

Marcel - "A specular reflection of a window still gives a round highlight, not a rectangular shaped one." Yup, you nailed it right there. That is exactly what I am talking about ;) Thanks for clarifying it so simply.

NanoGator - thanks for that in-depth analysis. Some great info you have written there. Don't worry, you didn't kill the thread at all - your contribution was valid, and I'm sure everyone appreciates it!

psil - I do want to put together a workshop on more Photoshop-specific stuff, but I will only do that right at the end. I want to go through all the specifics of the aspects of texturing first, and then go into their practical creation.

frog - "Those plain round highlights are one of the main reasons that so much CG makes the world look as if everything is made of plastic" - so true. That's why I use both - specularity does tend to make things look plasticy because of the round shape of the highlights. However, the reason I discussed the BRDF shader is because using anisotropic specularity does tend to make the highlights a lot less round, and thereby a little more realistic.
That said though, I do think that specularity has to be used carefully and in moderation to ensure a realistic look at the end.

playmesumch00ns - thank you so much for all that! Unfortunately, I do not know a lot of the details regarding that more technical stuff (such as Blinn and Phong shading models), and I ws hoping that somebody would post a bit about it all.
"But, as (i think) Leigh neglected to mention, we must then include some geometry to represent the light source." - oops you got me hehehe I did forget to mention that... Although I would think that it would be a pretty obvious thing to do. I always have luminous objects floating around where the lights are to represent the light sources - works like a charm.
Thanks for your explanations!

KEKS
08-20-2002, 09:08 AM
this really helped me i learned a lot
so if anyone saw my texturing head post
i use raytrace material as a submaterial to phong
and turn off the specularity down to zero and use my
painted map. Now if we pain the specularity map we will
be just guessing where the sports are. I understand the
irregularity and everying but I find that using raytrace material
worked better then withou it.
Anyone plz add to what I am saying if i am missing something.
plz check my posts too
thx :)
also what i am finding is that there is a lot of guess work at least for me at this stage when texturing. Can someone plz tell me what lights should be used when texturing? What is the workflow between lights in the scene and the texturing , especially when painting spec maps.

leigh
08-20-2002, 05:05 PM
Hmmm.... when I am texturing, I usually use a 3 point light setup :)
Basically I position 3 lights around the object ar varying intensities so that any flaws and all details will show up clearly :)

KEKS
08-20-2002, 06:06 PM
does anybody else have different workflow?

voyer
08-22-2002, 03:12 AM
I think that she is wicked for letting us all in on some really good basics.
I am wondering if I am going to have to go back to school or something.......can you learn all of this from books??? or the interent???
I am learning texturing and i am finding it to be the most challenging part of 3d. There is soo much to learn.
Anyone know any really good books?
I want photorealism.

Norman
08-22-2002, 03:18 AM
Okay all.. per Leigh's approval, I have a PDF for this.. please email me if you want it.. it won't let me attach it here..

email to : dave@voygr.com

Thankee.. :) (Also in DOC format)
( I have all of them in PDF/DOC as well)

NanoGator
08-22-2002, 03:32 AM
Try zipping it up and attaching it. :)

NanoGator
08-22-2002, 03:35 AM
Originally posted by KEKS
does anybody else have different workflow?

I render into different layers and do the adjustments in Photoshop. I do that more for getting the right colors and intensities with lighting, but it works for texturing too.

Another thing I do is I print an angle of the mesh really lightly, then draw on top of that. The result is hand-drawn textures. Eventually when I get a look I like, I take it to Photoshop and start finding elements to paste on top of the drawing.

Black&White
08-22-2002, 07:39 AM
hot spots are infact reflections of light source but we cant see light source reflection because it got highly diffused.

Norman
08-22-2002, 01:21 PM
Nope.. file is too big.. Sorry..

HapZungLam
08-23-2002, 10:21 PM
is adding spec/refl map a "must"? although the object is not shiny?

since every object is reflecting light, so we must add?

(because sometimes i m pretty lazy to add :p )

NanoGator
08-23-2002, 11:01 PM
There is really no such thing as a 'must' in 3D. The biggest most important thing you can do is consider it. Just be careful, though, because there are very few things on this planet that are 'matte'.

However, a shiny object may not necessarily have a specular reflection when photographed a certain way. I saw a photo of a wine-glass once that had specularity, but no reflections. How'd they do that? Simple: The photographer surrounded the wine-glass with black (tarps maybe?) so that no light was projected on the wine-glass to reflect other than the studio light. Interesting effect, really.

So there's a case where a reflective object didn't have a reflective property. (Much easier to do in CG than in real life...)

Here's my best advice: It's okay to not use specular/reflections in a given object, but be prepared to use them in unusual scenarios. A matte object will look shiny if it's wet, for example. Don't just leave it off all the time because it's not supposed to be shiny. (That's why i said the most important thing you can do is put consideration into it.)

One other point: The more attributes you assign to an object, the more complex it is, no matter how subtle the detail. Subtlety can sometimes make a bigger difference than the big details. One of the most convincing factors of the Toy Story movie, for example, is that nothing is perfectly placed in perfect perpendicularity. That is more important than say radiosity.

bri
08-24-2002, 11:30 AM
i can put the pdf/doc n my webspace. no traffic limits, plenty of space. send it to my mail and i'll post the link: martrash@terra.es

NanoGator
08-26-2002, 08:20 AM
Leigh, I have a question for ya:

I recently figured out how to do a Photoshop trick that allows one to seperate the color channel from the diffuse channel of any given image. The idea being you can texture an object with a color image and a diffuse image and get exactly the image you started with back out of itat 100% lighting. Is the info on how to do that of interest to you?

leigh
08-26-2002, 08:25 AM
Yeah, Nanogator - that sounds really interesting :cool:
Post it in the diffuse workshop thread - Diffusion Workshop (http://www.cgtalk.com/showthread.php?s=&threadid=11053)
:D

NanoGator
08-26-2002, 09:31 AM
Here it is, folks:

http://www.cgtalk.com/showthread.php?s=&postid=172078#post172078

:) Leigh, I'm particularly curious what you think of it, particularly if this process is of use to you. I haven't done much texture work lately so I'm curious what somebody who does a lot of it thinks. I was tickled when I got this technique working. :love:

bcole23
08-26-2002, 10:55 PM
I think that some, um, beginners, do not understand how the program extrapolates how reflective something is from a map. Eg. In the reflect map, do I put in a picture of my room or do I put in a grayscale map?

The different ways diffuse, reflect, and environment map slots are used are a bit confusing when starting out.

[I know, but I'm sure you could explain it so succinctly and eloquently, as you always do ;) ]

leigh
08-27-2002, 08:33 AM
Okay, let me explain a little more clearly ;) :

The reflection map that you place into your reflection channel in your surface editor is a indeed a grayscale map - the darker the gray, the less reflective, the lighter grey, the more reflective.

When making grayscale maps for texturing, the renderer takes the gray value of each pixel, and applies that value accordingly to the value of that attribute - in other words, if a pixel is 42% gray, that area will be 42% reflective.

The best way to start off a reflection of specularity map (or any other map for that matter) is to decide on the overall amount of that attribute that you want. In other words, of you don't want any part of it to go more reflective than 16%, then make a gray image in Photoshop that is 16% gray, and just darken the areas that you want to be less reflective.

When making maps like this, I personally tend to start off by the process I have explained above, and then just use the dodge and burn tools (in Photoshop 5) ;)

As far as a reflection environment goes, well if you want it to reflect your bedroom, then place that image into the environment slot in the surfaces settings (if it has one).
I can't remember where this option is in Max, but I know it is there somewhere...
In Lightwave, this option is under the Environment tab in the Surface Editor.
I'm not yet sure where these options are in XSI, or Maya :shrug:

Hope this makes sense! :D

bcole23
08-27-2002, 03:35 PM
I wish I could communicate as well as you! :buttrock:
I'd also like to add that this really doesn't just apply to reflection either. It's the same way you set bump, displacement, masks, etc etc.

Kaiser_Sose
09-01-2002, 09:59 AM
Originally posted by bri
i can put the pdf/doc n my webspace. no traffic limits, plenty of space. send it to my mail and i'll post the link: martrash@terra.es

is it up yet

Kaiser_Sose
09-01-2002, 10:46 AM
Originally posted by Leigh
Hmmm.... when I am texturing, I usually use a 3 point light setup :)
Basically I position 3 lights around the object ar varying intensities so that any flaws and all details will show up clearly :)

Can you post this setup please

bri
09-01-2002, 04:56 PM
there ya go... unless Leigh does not approve it:shrug:

[/URL]

and the part 4:

[URL=http://www.iespana.es/hecatonchires/files/Texturing for Dummies - Part 4.pdf] (http://www.iespana.es/hecatonchires/files/Texturing for Dummies - Part 5.pdf)

KEKS
09-01-2002, 07:13 PM
could you post 1,2,3 pdf's thx:)

bri
09-02-2002, 07:08 PM
sorry, there is a post made by leigh herself where the three pdf's are linked to a page :

if you click on the topmost link, you'll be in a page where the first 4 are (or at least, they were here last sunday)

dmcgrath
09-06-2002, 03:34 AM
Hey Leigh, great tuts here, I am learning and applying alot of yours and others techniques on my A&B challenge, but they arent good enough to post so Ill prob move them to a WIP when challenge is over.

On the question of reflection mapping, though. I am not familiar with MAX, so maybe there is just an environment reflection property there.
But for the Maya users out there, there are two(2) reflection channels. (Shown below)
The one with the slider is pretty self explanatory, and the little checkerboard on the right lets you define a grayscale relfection map of your choice.
And directly below that is a channel where you can define an actual full color map (ie. environment) when you click on the checkerboard.

Hope the pic helps others out there.:beer:

jsh3d
09-20-2002, 04:55 AM
:beer:

Thanks a lot leigh! I suck at textureing, so any help that I can get is great! This is a great thing that you're doing for everybody :D!

-Jsh3d

mabuffaloe
09-24-2002, 08:14 AM
Hi Leigh, this is my first time on this site, and I love your tutorials! Lots of great info. Anyway, I wanted to ask a question from way back in the first lesson, about determining texture map size. How do you calculate the image size if it will be used in gaming, where every bit of space counts? The advice is generally to keep them around 256 x 256, what do you suggest?

NanoGator
09-24-2002, 05:08 PM
Originally posted by mabuffaloe
Hi Leigh, this is my first time on this site, and I love your tutorials! Lots of great info. Anyway, I wanted to ask a question from way back in the first lesson, about determining texture map size. How do you calculate the image size if it will be used in gaming, where every bit of space counts? The advice is generally to keep them around 256 x 256, what do you suggest?

The advice I read in a magazine once was to make the texture as high res as possible while it's in development, then scale it down to your needs.

I haven't worked on a game, so take my advice with a grain of salt. :)

leigh
09-26-2002, 08:41 AM
I don't know all that much about games, but as far as I know, the size of the images used really depends on the game engine - more powerful engines can handle larger images.
The rule of thumb is - the best quality in the smallest size. I don't think I've ever heard of game maps being larger than 512x512 :)

NanoGator
09-26-2002, 04:44 PM
Ack! Leigh! What happened to your avatar! Somebody shrunk your head!!

leigh
09-26-2002, 04:50 PM
Hehehe yeah Sasquatch did it :p
I saw the pic, and thought it would be a nice change! :D

derelict
09-26-2002, 04:55 PM
by any chance this thread will move along soon? Will there b an update soon? I'll be waiting right here.


PLEASE UPDATE THIS, PLEASE!!!!:)

Dipesh (India)
10-30-2002, 08:47 AM
very informative topic, keep it up!

Ataru
11-05-2002, 07:28 PM
My first post here :) I was linked to this site by a friend whom i asked about advanced modeling/texturing tutorial's and techniques.I did not expect anywhere the level of quality and professionalism that I now see here.To Leigh you are amazing!How long have you been doing this?To everyone elce I am happy to be here and a part of this art community.I hope I can help as much as I ask questions ;)

leigh
11-06-2002, 07:17 AM
Hey there :D

Welcome to the forum :beer:

Thanks for the compliments, they mean a lot. I've been doing this stuff for many a year now :)
This is indeed a fantastic forum, and I'm sure that you will frequent it as much as we all do!
Looking forward to seeing some of your stuff, and having you contribute to the community :D:D

NanoGator
11-06-2002, 11:50 PM
Heh nice avvie Leigh. Make it urself? I kinda miss the old one tho
:cry:

leigh
11-07-2002, 06:08 PM
LOL It was actually drawn by Jeroentje :)
The whole pic is kinda funny actually... I'll post it sometime... ;)

epatnor
12-08-2002, 11:46 PM
Well, I just love your new avatar which is really cool (although I actually liked the old one too), but the work you're doing for us with your dummies series just R.O.C.K! 'Cause that's what I am at the moment... texturing dummie I mean ;)

Many thanks, just where would we be without your knowledge and expertise?!

Anyho, any chances of obtaining these tuts in more compact format (as you did with your first ones), like in RTF format or something? Any chance I missed that same question earlier in the thread? :)

epatnor
12-08-2002, 11:49 PM
Ehm just got hold of it :hmm: sorry

http://www.iespana.es/hecatonchires/files/Texturing%20for%20Dummies%20-%20Part%205.pdf

Thx again!

GUMP
01-25-2003, 03:29 PM
Great tuts... i do have a few questions though
since im a total newbie at anything 3d.
When making these textures I noticed
that if i leave the layers as is in Photoshop
and apply them to the color map in Maya
I get transparency that I never set.

So therefore, with all the different layers
in your photoshop image, save each
layer out as an individual image? How do you
go about saving all those layers for use in your
3d app?

What file type you mostly use when saving these
images, Tiff,JPG, BMP?? IF saved as a tiff
do you save the layers or do you compress them
(that is if you dont save them as individual images).

Please help a texturing newb...thnx

NanoGator
01-26-2003, 06:07 AM
Originally posted by GUMP
Great tuts... i do have a few questions though
since im a total newbie at anything 3d.
When making these textures I noticed
that if i leave the layers as is in Photoshop
and apply them to the color map in Maya
I get transparency that I never set.

So therefore, with all the different layers
in your photoshop image, save each
layer out as an individual image? How do you
go about saving all those layers for use in your
3d app?


Well, I'm not a Maya user and can't really comment on that problem. A screen grab would help. I can imagine, though, that Maya's reading the transparency of a layer or an alpha channel that may be set. I'd field it, but I need to see a render and the iamge you're using.

As for the individual layers, try turning the layers on and off for the right image you want, then go to File and 'Save as a Copy'.

smellovision
03-13-2003, 04:50 PM
Very cool!!! I love your work.

Coop.

marcusss
04-22-2003, 10:11 AM
ok, thanks a lot for your contribution!!

I am a Max user, and trying to grasp the subtleties of proper texturing... The thing that bugs me the most in the absence of a reflectivity map. If you put an image in the reflection slot, max puts this image as wich is being reflected on the object. Therefore, there is no direct control over reflectivity.

What do you max users do to overcome this?? I cant believe there is no way of showing max how to use a reflectivity map...

I like Maya'S interface, where the reflectivity and the reflecting maps are clearly and independently controllable.


Mark'huss
(Greatness Incarnate):cool:

haslingerDesign
05-21-2003, 12:00 PM
Thx again Leigh, can`t wait to begin with drawing my maps, so i keep it short.

]gRe[

Barbas
05-26-2003, 01:26 PM
Trully usefull and good tutorial cant wait for the next!

Razorwolf
06-24-2003, 08:25 PM
Leigh.. this is so great. I compiled all of the workshops into one word document and printed it out, and it's great lecture. It really helps me.. cheers :thumbsup: :)

djinn
07-01-2003, 09:44 AM
citizenvertex

Specular in that sense would mean it is also affected by reflection from surrounding areas that would increase the potential mass of light within the degree it is captured on the surface.. due to the atomic reconstruction inherited by the individual rays of light within a beam.. ..so it makes me feel that way...
lol =)

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