Why does LW have only Phong shading?

[CIM]

Because LW has a crappy Surface Editor. :-)

Anway, you can get the same basic effect as in other programs, but it won't be as organized. You could probably speed things up by making some basic Presets to start from.

[CIM]

Here's a plugin shader with some shading models:

http://katastro.fi/~eetu/bradford/

[leigh]

Thanks for the link, CIM.

Okay, now I was under the impression that the shading models are more to do with the renderer than with the Surface Editor - am I wrong?

[Mattoo]

I've often thought it an odd limitation before but it does make sense considering what Lightwave is/was intended for.

I think they chose one, flexible, shading technique purely for simplicity, much like the rest of LW. They could have given us all the others we're familiar with but it would have complicated what should be quite simple.
And if complicated is what you want then different shaders can be applied in the..... ummm... Shaders tab :)

I've used other apps that have many shaders available and I've never found it to be a benefit (or a drawback). For almost everything I'd end up using blinn or phong anyway as the differences are so subtle.

I suppose we can only guess why as I doubt the powers that be will answer. I'm certain there's no technical reason, just the way they designed the workflow. If someone really needed a Blinn shader they can write one and access it via the Shaders tab....

[KillMe]

i seen blinn shaders somewhere but for the life of me i ant rmeember where as the mattoo says though phong is jsut default others can put the otehrs in throught eh shaders tab jsut a question of finding them

[BoulYaBase]

Originally posted by Leigh
Okay, now I was under the impression that the shading models are more to do with the renderer than with the Surface Editor - am I wrong?

I'm sure someone will jump in and correct me if I'm wrong here, but shaders (i.e. plugins that are added to the Shaders tab in the surface editor) allow developers to create new algorithms for rendering LightWave surfaces based on whatever mathematical model they like.

This has allowed Worley to create great tools like G2, and Richard Jennings to create things like IFW2 Shaders, which gives LW users access to Blinn, Oren Nayer, Strauss, and other shading models.

[Aquaman]

IFW2 Textures have a Blinn option.

[CTRL+X]

MAX has a slew of shader types for hair, anistrophy, and the like, but these same options are available through LW plugins like G1 and G2 and Sassy etc etc etc.

[Mylenium]

The differences in appearance are marginal, I would say. I am also using Maya and rarely doing rather exotic stuff with custom shaders. Yes, certain shaders are supposed to do certain materials better like

Lambert, Oren-Nayar -> flat, chalky materials
Blinn -> metals
Hall-Torrance - > luminous materials

etc.

but it isn't that imortant in everyday work. The thing is, that you just may have to do some more tweaking (i.e. use a gradient with incidence to get a Blinn style reflection.

Mylenium

[MorBioS]

really great topic

Is there some site explain all about it??

I ever wonder have know about theses stuffs? :thumbsup:

thanks

[BoulYaBase]

There's an IFW2 v5 review here (http://www.critical-depth.com/Reviews_Software/PC_IFW2_v5/PC_IFW2_v5.asp) that includes renders of the LW teapot with several of IFW2's additional shading flavors (including Oren Nayer, Blinn, Strauss, Specular and Phong).

Scroll about halfway down the page to see 'em.

I'm no surfacing ninja, but I think it'd be tricky to recreate the looks of that Strauss shader, for example, with LW native. I don't think that increasing gloss and reducing spec would produce that same look. The Oren Nayer would be a challenge too.

(IFW2 Specular is pretty cool, btw. The highlights blow out nicely even without and image processing or post.)

:wavey:

[Arte]

Originally posted by BoulYaBase
There's an IFW2 v5 review here (http://www.critical-depth.com/Reviews_Software/PC_IFW2_v5/PC_IFW2_v5.asp) that includes renders of the LW teapot with several of IFW2's additional shading flavors (including Oren Nayer, Blinn, Strauss, Specular and Phong).

Scroll about halfway down the page to see 'em.

I'm no surfacing ninja, but I think it'd be tricky to recreate the looks of that Strauss shader, for example, with LW native. I don't think that increasing gloss and reducing spec would produce that same look. The Oren Nayer would be a challenge too.

(IFW2 Specular is pretty cool, btw. The highlights blow out nicely even without and image processing or post.)

:wavey:

You can pretty much do them all in LW standard without any effort (5 mins) so hope this is informative:) Strauss too btw. If I had more time I would post some images. BTW for strauss don't use spec use reflectivity imo.

Newtek hasn't put them in imo due to the pain in the ass they can be, as certain materials can only do such and such on such and such renderer. It is a nightmare to keep track of imo.\

X

[dies-irae]

here's some theory for those that are interested...


in the beginning there was flat shading.
you take the normal to the poly, you do a dot product with the vector of the light, you have a luminosity factor L.
for every pixel on your poly, you multiply the color by L and you've got the illumination.

Then you get Gouraud. for every vertex on your object you compute the normal average (using all the normals of the polys attached to the vertex)
you compute the L factor for this vertex and you interpolate the different L factors for every pixel in the poly (so a pixel in the center of the poly will have an average of the L factors of the vertexes)

Phong is like gouraud, only difference is: instead of:
1 - doing the normal average for every point
2 - calculate the L factors
3 - interpolate them for every pixel
it does:
1 - normal average
2 - interpolate THE NORMAL for every pixel
3 - calculate the L factor for the pixel using the NORMAL we just found.

blinn does the same thing, but in addition it uses a second vector to be used for specular (specular is computed by doing a dot product with the incidence angle of the light and the incidence angle of the camera)

the other systems have some differences in the computation of the L factor and the specular (it's a formula with some cosinus and some powers etc, so you change the formula parameters, you change the way the surface responds to the light)


the important part is that all of the above are NOT material properties, it's just the way the renderer reads them. Lightwave uses only Phong (that's not entirely correct because it isnt exactly Phong but that's another story...) so it doesnt have to change the rendering type for every object... well maybe that helps lw's renderer being that fast!

[MorBioS]

thank you dies-irae
good introdution to me =)

do you have know any url explain about it and others shades?

[vapulus]

The problem with Phong has always been the strange speculars you get at extreme angles to the light. The edges of objects would sometimes pick up absurd streaks of speculars, even though it was physically impossible and looked horrible. I don't notice these issues with LW's phong, so I'm guess it's an edited phong like phong-e. Am I right in that assumption? I don't know the inner-workings of lightwave, but I know I've never gotten that scary phong spec in it. =) As long as I don't get that scary spec, I don't really see a reason to use blinn over phong. They can do the same stuff, phong was just never nearly as editable in other packages. It works fine for me in LW. =)

[zuzzabuzz]

http://www.iro.umontreal.ca/~roys/softimage/html/shade/surface_shaders.html
Under "Shading Models" (1/4 down the page) are some good paragraphs and pictures describing some of these models.

It's actually kind of hard to find examples of all of these shaders in one spot, which makes me wonder how often they are used + discussed in general 3D work. I think a lot of these can be 'simulated' using gradients keyed on incidence angles of lights or cameras, and variations of color filter and color highlights in the advanced surface tab.

Mylenium, and others, already said as much, i guess. :-) I like pictures though.

[leigh]

Those IFW shaders certainly look very cool! Does anyone here have them and can offer any other opinions? :)

[Arte]

Hi Leigh,
I don't own them yet but have seen them in use. They are fantastic, especially for a newbie who needs results fast.

I am not really into the surfacing fluff. However there are killer gradient options not in LW, which while easily simulated by custom gradient images (I have hundreds created before gradients appeared in LW) IFW integration cannot be faulted. Also way more flexible than using image maps.

As I said earlier there is nothing there which you can't do without the set, but, it's more work.

LW's gradients need an overhaul, IFW kinda does it.

X

[BoulYaBase]

Originally posted by Leigh
Those IFW shaders certainly look very cool! Does anyone here have them and can offer any other opinions? :)

Hey Leigh,

After buying and using them for a couple of months, I was so pleased with the results that I decided to write that review, which includes just about everything I have to say about them.

If you have any questions about the review, feel free to drop me a line or post them here. I'm one of many who owe you something for all those great texture guides and informative posts you've given us.
:buttrock:

Be sure to look at the IFW2 Web site, too:
http://shaders.org/ifw2_textures/

There's a gallery, manual, and other info there.

[Lamont]

This was a nice read. ^_^!

[Freak]

LW usually uses diffuse shading methods,
But many shaders, at least 2 freeware shaders offer Oren Nayar methods, one is open source even.

Also the Shades Project by Marvin Landis,
offers a version of the ee Oren Nayar shader, as well as, most of the other shaders in the Shades Project have options to provide either diffuse or oren nayar illumination methods.

As well as IFW2 which has a few shading modes, like Blinn, Oren Nayar, Antistropic, Phong, Cel. etc...

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