Join Aaron F. Ross for an in-depth discussion in this video Preparing for baking, part of 3ds Max: Advanced Materials.
- [Narrator] The render to texture dialogue allows you to save any map out as a bitmap file. So you can convert from a procedural texture to an external file texture that can be read by any application and that's good for interoperability. It's also good for rendering certain effects that are not supported by the current renderer. Let's say for example, I wanted to use an ambient occlusion pass as a dirt map. I want some of the areas in the crevices here in the sculpture to be a slightly different color.
An ambient occlusion would be an easy way to achieve that but if I wanted to render in the ART renderer, I would not be able to use ambient occlusion because it's not included in the feature set and it almost doesn't need to be because ART, being a physically based path tracer, will simulate the way that light doesn't reach into those crevices in the rendering, just by default but if we want to use ambient occlusion as a special effect and ambient occlusion is not supported by ART at all, what we can do is render out the ambient occlusion in Mental Ray as a bitmap and then apply that in our shading network and be able to get that effect in ART or really any renderer.
There are two preconditions before you can use render to texture. First, all of the objects must have good UVs or good mapping coordinates and these three objects have pretty basic coordinates but they will be suitable for this example. I can just show you one of them if I select the helmet and go into the modify panel. It's an XRef object but I can stack modifiers on top of that, from the modifier list, pull down.
I want to scroll near the bottom and choose unwrap UVW and then scroll down in the panel and click edit UVs, open UV editor and we can see these two shells, those are elements or shells of UVs and they meet the requirement, that the UVs don't overlap and they also meet the other requirement for render to texture, which is, the UVs all fit within the zero to one parameter space of the texture and this is the U dimension from zero to one and the V dimension from zero to one and everything has to fit within that square.
Okay, so those are the requirements. We have to have good UVs and those UVs have to fit within the zero to one space. I'll close the edit UVW's dialogue and I can delete this unwrap UVW modifier. I don't really need it. Just select it and click the trash can. Okay, those are the preconditions before we can use render to texture. In this course on materials, we're covering material parameters and building shader networks and the whole process of UV layout is out of scope for the course.
In fact it could be an entire course in itself. That's all we need to do in order to prep our models for render to texture.
- Streamlining material editor workflow
- Managing XREFs and materials
- Laying out a scene for material testing
- Using the Physical Material
- Controlling highlights with Roughness
- Directing reflections and refractions
- Simulating translucency and scattering
- Building a shading network
- Combining and color correcting maps
- Baking maps such as ambient occlusion
- Procedural mapping with Substance
- Using relief maps: bump, normal, and displacement