specularity problem

[UberModeler]

sorry its blurry had to so i could post it.

[DaForce]

can you post a render closer to the object that is meant to have the specularity. If its that little skull looking things, then just render that, so that you can see it nice and big.

Then we can help you

[jyrgen]

Your first scene seems to be lit by only a Skylight (brazil or max, does not matter). Skylights IMHO never affect specular parts of your material, but only diffuse and/or ambient. So your material might be perfect, but there is no light in your scene that would invoke specularity.

[joconnell]

Yup, stick in a directional light and you should get better results. Also don't be afraid to turn up the specular level - I've used up to 1000 on a few recent things and it gives you that range of soft and sharp burnt highlights that you'd get more commonly.

[leigh]

As other people here have mentioned, the spec is not showing up because of your lighting.
That render is what is often called a "clay render", and to get that effect one normally deactivates global lighting (in this case substituting that for a sky dome), which means that you get so actual direct lighting, just ambient lighting, which does not show up specularity at all ;)

If you change this scene to a proper lighting setup, you will see the specularity.

joconnell - using such extreme spec amounts can be kinda dangerous. That burnt out effect you are referring to is called bloom, and there are other ways of doing this using post processing filters (well, you can do that in LW. I'm sure Max has something similar, maybe in Video Post) :)

[ZeBoxx]

Leigh,

I don't think John's referring to specular bloom. And no, setting values that high is not at all dangerous - it's not about to cause a self-destruct of the computer.

What it does do is more accurately simulate the intensity of a light, as you're more likely to find it in the real world around most of us.
It's also pretty much a requirement if you do want to simular specular bloom or render proper depth-of-fielded/motion blurred images.
(of course a reflection of a truely 'bright' object is better since a 'highlight' in the terms of CG apps is a cheap fake anyway)

Whether one finds it aesthetically pleasing or not is another matter.

Best regards,
Richard Annema

[leigh]

ZeBoxx, I meant "dangerous" as in overly increasing the spec amount can sometimes lead to your object being reduced to little more than an unidentifiable burnt out white thing in your renders. Spec can be an extremely strong effect, and shouldn't be immediately pumped up to 1000 if you are having trouble seeing it, that's all :)
The fact is that if your spec is not showing up at all, the chances are more likely that it is something to do with your lighting, than it is to do with your actual spec map, in many cases.

What it does do is more accurately simulate the intensity of a light, as you're more likely to find it in the real world around most of us.

Yeah, but how often do you actually get SUCH incredibly intense reflections of light on a surface? Unless an object is under a very intense flourescent light, or is in direct sunlight at noon, you just aren't often going to have such an intense effect. Even placing a shiney object under direct lighting from a househol light is not going to have a very overblown effect :shrug:

And, as you mentioned, the fact that specularity in CG is technically a fake (just as it is in paintings), it should be used pretty carefully as well.

[UberModeler]

its WAS the lights....i feel silly. I put one in and didnt save and started to work on it again so i THOUGHT i had one. but i didnt. here is what i looks like now. not sure if its right. i know it need to be dirtier.


also do you HAVE TO make specular maps? or just pick a material that has good specualar stuff?

[UberModeler]

bottons are too close....

[leigh]

Originally posted by UberModeler
also do you HAVE TO make specular maps? or just pick a material that has good specualar stuff?

Yeah, you have to use spec maps, even if you use just a procedural one.
The fact is that NOTHING in reality has a perfectly clean surface, so there will always be an unevenness to the light being reflected off the surface.

Also, when looking at an object like you are making - think logically: the metal and the paint would have different levels of specularity ;)
So make sure that your spec map shows this. The paint is likely to be glossier, while metal has a broader specularity (often with anisotropy in it, which results from the machining of the metal) :)
So what you need to do is take your colour map, and make the areas that are metal less speccy, and the areas where there is paint slghtly more speccy. Also, make a gloss map to help define the falloff of the specular too - the metal would have a very low gloss amount (almost 0 probably) while the paint would have a higher gloss amount to tighten the specular falloff :)

[UberModeler]

spec maps are based on black and white right? so i would have to paint areas that i wanted dull in black and areas that i want to be shinny white?



quote make a gloss map to help define the falloff of the specular too - the metal would have a very low gloss amount (almost 0 probably) while the paint would have a higher gloss amount to tighten the specular falloff


does anyone know how you do this is max? thanks leigh for the help this is my first attemp so i have no idea whats going on. the work flow is the hardest cause of 3 programs im using.. so it get hectic.

[leigh]

Well, using just black and white isn't advisable since black is absolute 0 and white is 100%. You need more variation. So use grays. And yeah, the lighter the gray, the stronger the spec, while the darker the gray, the less spec.

To make a gloss map, make one similar to the spec map, but slightly more contrasty, since gloss works close to the spec, but needs to tighten or spread the specularity.

So basically, if you want an area to be fairly speccy as well as fairly glossy, you would make those areas in both maps rather light shades of gray. However, the gloss amount is usually lower the the spec amount, except for very plasticy surfaces.

Then you just put the spec map into your spec channel in the material editor, and put the gloss map into the gloss channel. If you have made your maps precisely, then this will work well.

Remember that the shades of gray in the maps will give you that exact corrosponding channel value when applied to that channel - for example, a pixel that is 37% gray in your specular texture will render as 37% specular :) That is, provided that your base values for each channel that you have actually set using the value spinners on the material editor are 0. If these values are set higher, then those values will determine the base value for the textures, and will consequently adjust all the values within the image respectively higher :)

If you want an idea of more or less what these maps can look like, and consequently what kind of effect they have when you render, have a look at two breakdowns that I did of some texture work I did - here (http://leigh.cgcommunity.com/making_of.htm) :)
If you look through those, you will see the textures I made and how they looked when rendered :)

Good luck!

[UberModeler]

wow great information. i didnt really think that about greys. neat. THanks so much for the tips. you are a true hero of the 3d world. When i get a chance (dotn have my comp) ill make those spec maps and see what i can do. ty

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