blender-pbr-materials

1# PBR Materials
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3The execution model is in `blender-core`. Measured values are in [references/pbr-values.md](references/pbr-values.md).
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5## Fast paths
6- Texture set → material: `scripts/build_pbr_material.py -- --name M_Crate --textures //tex/crate --objects SM_Crate`. It detects maps by filename (Poly Haven, ambientCG, Substance, UE suffixes), sets color spaces, splits ORM, flips DirectX normals, and routes AO to glTF.
7- Solid physically-plausible material: `--preset gold|iron|plastic|rubber|wood|glass|skin|...` with an optional `--color R G B` (sRGB).
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9## The rules (violations are what make renders look "CG")
101. **Metallic is binary**: 0 (dielectric) or 1 (raw metal). Use in-between values only on transition pixels (dust or rust edges on metal). Painted metal counts as dielectric.
112. **Base color = albedo with no lighting**: no baked shadows/AO/highlights. Dielectric range is sRGB ~30–240 (linear 0.012–0.87): charcoal ≈ 50, fresh snow ≈ 240. Metals: base color = F0 reflectance, sRGB 180–255, never dark.
123. **Roughness carries the realism**. Break it up with grunge, smudges and wear. A constant roughness value looks fake; vary it ±0.1–0.2 across a surface.
134. **Color spaces**: Base Color and Emission use `sRGB`. Roughness, Metallic, Normal, AO, Height, Opacity and ORM use `Non-Color`. A wrong color space is the #1 bug (washed-out normals, wrong roughness).
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