Physicaly based viewport shader for max?
polycounter lvl 19
Does anyone know of a viewport shader for max that uses the increasingly popular physically based approach - instead of determining specular reflections with a specular map, you use a specular mask and a roughness/smoothness map. This is a fairly common approach these days, but every max viewport shader I know of uses the traditional approach.
Thanks in advance for any recommendations.
Thanks in advance for any recommendations.
Replies
Meanwhile, wouldn't the built-in mental ray and it's custom shaders suffice if you are just looking for some portfolio renders? I know it's not real-time, but the Realtime and Offline rendering worlds have been converging recently, at least feature-wise. Obviously there are some large exceptions, like with special types of materials that include things like SSS, etc. in addition to the offline renderers' insanely high Image Quality.
However, most game model portfolio renders today are already post processed and anti-aliased far beyond whats possible in realtime. I'm not sure that that would be considered 'cheating' since a lot of those features are at least partially supported in next-gen realtime graphics, but IDK, I want to know what you guys think.
http://www.thetenthplanet.de/archives/255
here's a good link.
I did implement on myself ( not quite this one) for maya and that quite simple.
I guess the answer is no! Thanks everybody for your replies.
However, if for example you're doing Skin, then you need Blinn + Phong due to surface curvature which is impossible to mimic with a single specular.
If you're looking for a specific type of metal, then Cook-Torrance, for all it's artist unfriendly parameters, would serve well, but cannot be used for much else.
Anything in particular you're looking for?
1. It looks like Drew++ is working on a PBR shader in the Tech Artists WAYWO thread.
2. I also found a solution that is pretty damn sweet. I had never heard of Octane Render, but it's a GPU renderer that is near real-time and uses PBR
http://render.otoy.com/
Check it out!
This! Spec maps are slowly becoming a thing of the past! Gloss maps (aka roughness maps) are all we're gonna need in the near future! And I can't fucking wait.
http://www.marmoset.co/skyshop
You still need specular to define materials.
Not exactly right! They absolutely need specularity, since it's part of the BRDF equations which drive these shaders! It's the core of a "microfacet". Specular map is 100% must. RGB Specular map controls the f0 of the Fresnel term which controls the reflection intensity/Fresnel and color. The gloss map simply controls the roughness/specular cone angle of any surface. We end up calling this direct lighting. Sorry, no cubemaps here! In game engines we use punctual light sources (directional / point / spot lights) for direct lighting.
Indirect Lighting we generally call ambient lighting, which is comprised of diffuse ambient, and specular ambient( our cubemap reflections ). The cubemap reflection uses a pre-blured mipmap which should be blurred according to our BRDF term. We use the gloss map to select the mip level. The color and brightness of ambient specular also relies on a Fresnel f0, which is controlled by an RGB specular map!
Coming soon!
The point is that most renderers and engines treat reflections and specular as different parts of the shader. For example the 3dsmax standard material. Even with vray or mentalray you can seperate specularity and reflectivity, but then it gets physically inaccurate.
Game engines currently dont have real specular reflections. Reflectivity allways needs to be set up seperatly, but i guess this will change in the near future.
Not quite, as pedro says, just think of it all as specular reflection. You still need a spec or substance map to set base reflectivity, and gloss map to set roughness/glossiness. Though you're right in the sense that specular and reflection shouldn't be thought of as separate components, which they often are in game engines.
Toolbag 1 actually operates very similar to your average PBL shader works, with how it handles specular reflection. Skyshop is very close to Toolbag 1, though its a little more advanced in some cases, and Toolbag 2 will be a bit more advanced than Skyshop when it comes out as well, with gloss masked fresnel and screen space reflections, among other things.