Advanced Materials & Shades

Module 2: Advanced Materials & Shades

1. PBR (Physically Based Rendering) Workflows

PBR ensures materials behave realistically under varying lighting conditions by adhering to energy conservation and real-world physics.

• Metal/Rough vs. Specular/Glossiness Workflows

• Metal/Rough (Modern Standard)

• Base Color: Diffuse albedo (non-metals) or reflectance value (metals).

• Metallic Map: Binary (0 = dielectric, 1 = metal).

• Roughness Map: Controls microsurface scatter (0 = smooth, 1 = rough).

• Advantages: Simpler workflow, widely supported (UE5, Unity, Substance).

• Specular/Glossiness (Legacy)

• Diffuse Map: Only for non-metals (metals are black).

• Specular Map: Defines F0 reflectance (e.g., 4% for plastics, 50-100% for metals).

• Glossiness Map: Inverse of roughness (1 = polished, 0 = matte).

• Use Cases: Older engines (e.g., Marmoset Toolbag).

• Microsurface Details

• Anisotropy: Simulates directional roughness (e.g., brushed metal, hair).

• Clear Coat: Adds a secondary glossy layer (e.g., car paint, varnished wood).

2. Procedural Texturing

Procedural textures are generated mathematically rather than from bitmap images, allowing infinite resolution and dynamic adjustments.

• Node-Based Shading (Substance, Blender Nodes)

• Substance Designer:

• Non-destructive workflow using procedural nodes (Noise, Gradient, Warp).

• Advantage: Seamless tiling, easy iteration.

• Blender Nodes:

• Shader Editor combines textures/math for complex materials.

• Example: Mixing Noise + Musgrave for organic surfaces.

• Tiling & Masking Techniques

• Tiling: Avoids repetition via:

• Triplanar Mapping: Projects textures along 3 axes (good for terrain).

• Variation Layers: Overlaying multiple noise patterns.

• Masking: Combines materials (e.g., dirt on concrete) using:

• Vertex Painting (real-time engines).

• Gradient-Based Masks (slope, curvature).

3. Displacement & Parallax Effects

Enhances surface detail beyond normal maps, adding geometric depth.

• Tessellation vs. Parallax Occlusion Mapping (POM)

• Tessellation: Subdivides geometry at render time.

• Pros: True geometric detail.

• Cons: High GPU load; requires adaptive algorithms.

• Parallax Occlusion Mapping: Fakes depth via ray-marched heightmaps.

• Pros: Lightweight; works on low-poly meshes.

• Cons: Artifacts at extreme angles.

• Vector Displacement (ZBrush to Renderer)

• *Stores 3D direction + magnitude* (vs. heightmap’s 1D data).

• Use Case: Extreme deformations (e.g., wrinkles, sculpted details).

• Workflow: Export as .EXR from ZBrush, apply in renderer (Arnold/Redshift).

Key Takeaways:

• PBR Workflows depend on engine compatibility (Metal/Rough for modern pipelines).

• Procedural Texturing offers flexibility but requires node-graph expertise.

• Displacement Choices trade performance for fidelity (Tessellation > POM > Normal Maps).