cloud_raymarch_v4

Volumetric-sky cloud raymarcher, v4. Adds procedural detail noise computed in-shader on top of the large-scale texture silhouette (removes v3's voxel-grid blockiness) and uses multi-distance shadow sampling (4 geometrically spaced strides) instead of a cone trace. Reads the cloud volume + occupancy textures and writes the lit raymarch result.

Bindings (see bindings.yaml): clouds (texture3d), occupancy (texture3d), cloud_smp (sampler), out_tex (storage2d rgba16f), U (read array<f32> uniforms).

Usage: dispatch by identity with compute.dispatchEx("@builtin::systems.volumetrics.shaders.cloud_raymarch_v4", ...) (textures/sampler/storage texture require resource binding, not positional buffers) — it resolves to the shader's stable guid and auto-compiles on first use (no setup).