Interface CreateLightingBitOptionsAdvanced

Options for createLightingBit: the shading math of a lighting model, such as toon or Blinn-Phong, around a light loop the factory writes

The generated fragment lighting slot runs:

preLighting
for (each light that can reach this fragment) {
  work out light, lightDir, attenuation, nDotL and shadow, or skip the light
  perLight
}
postLighting
Copy

1. In preLighting, declare and zero your accumulators, such as directLight, and work out anything that doesn't depend on the light, such as nDotV.
2. In perLight, add this light's share to them. continue; skips the rest of this light. Lights that don't reach the fragment or that the surface faces away from never get here.
3. In postLighting, write finalColor from the accumulators and whatever the material bit declared, such as emissive. Exposure, fog and tone mapping run after it.

The loop sits in a block of its own, so names these snippets declare aren't visible to later slots such as end.

What perLight can read

Anything else the model needs, such as albedo and roughness, comes from the material bit that runs before it. The light's kind is light.kind in WGSL and light.type in GLSL; compare it with LIGHT_DIRECTIONAL, LIGHT_POINT or LIGHT_SPOT.

Lobes

Another bit in the descriptor can add per-light math to this loop, rather than run a second loop that samples every shadow again, through the fragment slots lobePreLighting, lobePerLight and lobePostLighting. Each runs after the matching snippet here, in the order the lobe bits are listed, so lobePostLighting sees the assembled finalColor and can rewrite it.

Requirements

Use the bit in a material with BaseMaterial3D#lit on, the default. A pass's own shader can't run it.