Metal

Target: Three.js 0.187.0, three/webgpu and TSL node materials from three/tsl; WebGPU only, no WebGL fallback, no GLSL strings.

Physical categories

Distinguish:

• painted metal
• bare aluminium
• stainless steel
• polished steel
• cast iron
• machined metal
• brushed metal
• galvanised metal
• oxidised metal
• weathered structural steel

Do not use one generic metallic material for everything.

Core response

Control:

• metalness
• roughness
• specular response
• base colour
• normal variation
• anisotropy where appropriate
• clearcoat only when a coating physically exists

Brushed metal should have directional anisotropic response.

Surface variation

Use subtle procedural variation for:

• machining marks
• brushing
• fine scratches
• oxidation
• dirt
• fingerprints
• edge wear

Variation should be correlated with physical causes.

Wear

Exposed edges can show more wear. Recesses can accumulate dirt. High-contact areas can become polished. Horizontal exposed surfaces can collect deposits.

Do not apply uniform random noise.

Scale

Large structural metal should have broad, restrained variation. Close-up machined components can have finer detail.

Train/rail guidance

Train exterior: usually coated/painted metal rather than bare metal.

Rails: steel with directional wear, polishing and environmental oxidation.

Underbody: darker, rougher, dirtier metal with higher variation.