3D Texturing Texture Baking & Rendering 2 — Questions and Answers
Question 1: What is the primary purpose of a lightmap in real-time 3D rendering?
- Store UV layout information across multiple UDIM tiles
- Pre-bake static lighting data into a texture for efficient real-time use (Correct answer)
- Define color temperature values for dynamic scene lights
- Map HDR environment values onto material roughness properties
Correct answer: Pre-bake static lighting data into a texture for efficient real-time use
Lightmaps pre-compute static lighting including shadows and indirect bounces into textures, allowing real-time scenes to display complex lighting without expensive runtime calculations.
Question 2: What information does a thickness map store when baked from a mesh?
- The distance from one surface of the mesh through to the opposite surface (Correct answer)
- The height variation of surface microbumps for displacement
- The glossiness at each surface point derived from roughness data
- The edge sharpness between adjacent UV chart boundaries
Correct answer: The distance from one surface of the mesh through to the opposite surface
A thickness map stores how thick the mesh is at each point by casting rays inward to the opposite surface, making it useful for subsurface scattering and translucency shaders.
Question 3: What is the primary use of a curvature map in a PBR texturing workflow?
- Controlling UV stretching in concave mesh regions
- Driving wear effects, edge highlights, and cavity darkening procedurally (Correct answer)
- Storing directional light data for runtime global illumination
- Mapping vertex normals to world-space coordinates for export
Correct answer: Driving wear effects, edge highlights, and cavity darkening procedurally
Curvature maps highlight convex edges for wear or highlights and concave cavities for dirt or darkening, making them essential for procedural smart material masks.
Question 4: In Marmoset Toolbag's baking panel, what do the 'Max Frontal Distance' and 'Max Rear Distance' settings control?
- The maximum UV chart size permitted per island in the bake
- The output texture resolution limits for the baked maps
- How far projection rays extend forward and backward from the low-poly surface (Correct answer)
- The polygon budget enforced on the high-poly input mesh
Correct answer: How far projection rays extend forward and backward from the low-poly surface
These settings define the reach of baking rays in both directions from the low-poly cage, controlling how much of the high-poly mesh is sampled from each direction.
Question 5: Why is padding (also called dilation or bleed) added around UV islands in a baked texture?
- To increase the total UV space available for island placement
- To prevent visible seam artifacts at island edges during mip-mapping and filtering (Correct answer)
- To add gradient borders used in post-processing compositing
- To automatically merge overlapping UV islands in the layout
Correct answer: To prevent visible seam artifacts at island edges during mip-mapping and filtering
Padding extends the baked color outward from UV island edges, preventing seams from appearing as the texture is filtered or sampled at lower mip levels.
Question 6: Which baking pass produces a grayscale map where concave areas like crevices and corners appear darker?
- Curvature map
- Normal map
- Ambient Occlusion map (Correct answer)
- Position map
Correct answer: Ambient Occlusion map
An Ambient Occlusion map calculates how much ambient light reaches each point based on surrounding geometry, producing darker values in occluded crevices and corners.
Question 7: Which map type stores directional lighting information that allows a surface to be relit after the bake is complete?
- Albedo map
- Directional lightmap (dominant light direction map) (Correct answer)
- Roughness map
- Height map
Correct answer: Directional lightmap (dominant light direction map)
A directional lightmap stores the dominant light direction at each texel alongside intensity, enabling relighting of baked surfaces while preserving shadow detail.
3D Texturing Texture Baking & Rendering 2
What is the primary purpose of a lightmap in real-time 3D rendering?