When setting up materials for StemCell there are some general setting that must always be used. These settings are necessary to maximize consistency and portability to other renderers.
- HGlossiness must remain locked so that RGlossiness is the only one affecting the render.
- Fresnel reflections must always be on in order to achieve more realistic reflections.
- Set IOR value for material within dielectric or metallic range for intended material using the same texture set. If multiple IORs of the same type, only dielectric or only metallic, are represented then set the IOR to the average of the IORs. The value difference between same material types is minimal in the render.
IOR values can also be set on the Refraction IOR settings as long as the Fresnel IOR is linked.
BRDF type must always be set to GGX
Set all map contribution slots to 100.0
Texture Map Settings
- Load _Diffuse map with matching material name to Diffuse map slot
- Load _Specular map with matching material name to Reflect map slot
- Load _Glossiness map with matching material name to RGlossiness map slot
- Apply a Normal Bump node to the Bump map slot. Load _DX_Normal map with matching material name into Normal map slot of the Normal Bump.
Glossiness and Normal map are linear maps and must be loaded with Gamma Override set to 1.0
Set blur value on all texture maps to 0.01 so the texture maps details do not get blurred
Additional Texture Maps
Depending on your model, you may have additional texture maps like Opacity or Emissive maps. These maps follow the same rules as the core required maps.
- Load _Opacity map with matching material name to Opacity map slot
- Load _Emissive map with matching material name to Self-illum map slot
What if my texture map set has multiple material types?
There are some situations where a material may require a dielectric and metallic materials on the same surface. See When to use Blend Materials for more information on these situations.
When an individual dielectric or metallic material can not be separated by object, that is the only time a blend material needs to be used. The Blend material is used to combine the 2 different IORs for dielectrics and metals. This way one material applied to the single object represents both surface types. A dielectric version of the material is created as Material 1 using correct low IOR value. A copy of that material is made for the metallic version as Material 2 with correct high IOR. The Metallic map is used as the Mask.
The Metallic Map is being used to mask which parts of the object get the dielectric material, and which parts get the metal material. Notice that the IOR values of each material are very different.