3D Texturing 3D Texturing Materials & Surface Properties 1 — Questions and Answers
Question 1: In a PBR metallic-roughness workflow, what does a metallic value of 1.0 indicate?
- The surface is a pure metal and reflects light according to Fresnel equations (Correct answer)
- The surface is completely rough with no reflections
- The surface has a subsurface scattering effect
- The surface is fully transparent
Correct answer: The surface is a pure metal and reflects light according to Fresnel equations
A metallic value of 1.0 tells the PBR shader to treat the surface as a conductor, using the albedo as the reflective tint rather than diffuse color.
Question 2: What does a roughness value of 0.0 produce on a PBR surface?
- A perfectly mirror-like, sharp specular reflection (Correct answer)
- A completely diffuse, matte surface
- Maximum subsurface scattering
- A fully opaque surface with no highlights
Correct answer: A perfectly mirror-like, sharp specular reflection
A roughness of 0.0 creates a perfectly smooth microsurface, resulting in sharp, mirror-like specular reflections.
Question 3: What is the purpose of an Ambient Occlusion (AO) map in a PBR material?
- To add soft shadowing in crevices and contact areas that simulates indirect light occlusion (Correct answer)
- To define which parts of the surface are metallic
- To store the surface normal direction for lighting calculations
- To control the transparency of the material
Correct answer: To add soft shadowing in crevices and contact areas that simulates indirect light occlusion
AO maps store pre-computed soft shadows in concave areas, adding depth and grounding to a PBR material under any lighting.
Question 4: What is Subsurface Scattering (SSS) used for in 3D materials?
- Simulating light that penetrates and scatters beneath the surface of translucent materials like skin or wax (Correct answer)
- Generating normal maps from displacement data
- Creating reflective surfaces like mirrors
- Tiling textures seamlessly across large surfaces
Correct answer: Simulating light that penetrates and scatters beneath the surface of translucent materials like skin or wax
SSS simulates how light enters a surface, scatters internally, and exits at a different point, which is essential for realistic skin and candles.
Question 5: In PBR materials, what is the F0 (Fresnel zero) value used to define?
- The base specular reflectivity of a non-metallic surface at a 0-degree viewing angle (Correct answer)
- The roughness at zero viewing angle
- The metallic intensity at grazing angles
- The UV tiling frequency
Correct answer: The base specular reflectivity of a non-metallic surface at a 0-degree viewing angle
F0 defines how reflective a dielectric (non-metal) surface is when viewed straight-on, typically around 0.04 for most non-metals.
Question 6: What is a 'cavity map' used for in texturing?
- Darkening fine surface recesses and micro-crevices to add micro-detail depth (Correct answer)
- Defining large-scale surface transparency
- Storing vertex color data
- Baking per-pixel lighting from a point light
Correct answer: Darkening fine surface recesses and micro-crevices to add micro-detail depth
Cavity maps capture extremely fine concave detail like pores and scratches, used to modulate specularity and color in those areas.
3D Texturing 3D Texturing Materials & Surface Properties 1
In a PBR metallic-roughness workflow, what does a metallic value of 1.0 indicate?