threejs-procedural-materials

name	threejs-procedural-materials
description	Author production procedural materials in Three.js. Use for hybrid texture-backed PBR soil and moss with procedural displacement and masks, upward-facing model moss accumulation, atlas filtering, specular AA, planet-space fields, terrain wetness, lava and emissive surfaces, per-instance dissolve, authored PBR identities, derivative normals, and custom direct-light shadow modulation.

Procedural Materials

Build a material from surface identity and causes. Color, roughness, metalness, normal, transmission, and emission should describe the same surface—not unrelated noise textures.

Material graph order

stable coordinates
  → structural fields
  → material identity weights
  → causal modifiers
  → filtered microstructure
  → PBR channels
  → lighting/shadow extensions

Read references/procedural-pbr-system.md for atlas filtering, specular AA, planetary coordinates, world-height wetness, per-instance dissolve, and authored PBR response bundles.

Read the sculpted gallery frame geometry for walnut, antique-gold, and ebony texture/roughness/metalness/clearcoat bundles under a grazing-light setup.

Read the procedural planet surface for shared geological, climate, water, biome, roughness, and derivative-normal causes on a procedural planetary surface.

Read the analytic wave optics for coupled reflection, refraction, absorption, filtered microstructure, resolved crest response, and their diagnostic channels.

Read the lava flow surface material for raymarched procedural height fields whose normals, rock/lava identity, emission, glow, embers, fog, and grain are coupled to one material cause stack.

Required controls

• real or perceptual texture scale;
• material identity weights;
• roughness range and micro-normal strength;
• the causal fields required by the selected material pattern;
• distance/derivative filtering;
• specular antialiasing;
• channel and mask debug modes.
• emissive-material debug modes when the material owns glow or volumetric accumulation.

Read references/hybrid-soil-moss-surface.md and the hybrid soil and moss implementation for texture-backed soil and moss albedo, AO, roughness, and normal microdetail combined with procedural mound displacement, moisture, moss coverage/height, and warped cellular cracks. Do not describe its surface identity as fully procedurally synthesized. When moss must also settle onto a model, read the model moss implementation for model-locked coverage, upward-face accumulation, displaced thickness, and shared moss PBR identity.

Failure conditions

• every PBR channel samples independent noise;
• roughness is a scalar afterthought;
• high-frequency normals survive below one pixel;
• triplanar projection has visible orientation or scale seams;
• atlas padding is ignored under mipmapping;
• custom lighting removes energy conservation without an explicit stylized goal;
• post-processing is used to hide unstable highlights.

Routing boundary

Use $threejs-procedural-fields when the main problem is designing shared scalar/vector causes. Use $threejs-procedural-planets for a complete orbit-to-close-approach body, not merely its material. Use $threejs-parallax-occlusion-mapping when a height field must own ray-marched intersection, silhouette coverage, or relief-aware shadows.