emission_raymarch

Marches a camera ray through an emissive volume and writes the result to a 2D target. Emission accumulates along the ray and density attenuates what is behind it, so a volume reads as light rather than as a surface.

Bindings

name	kind	what it is
vol	texture3d	the volume marched — RGB emission, A density
smp	sampler	how vol is filtered along the ray
out_tex	storage2d (rgba16f)	the image the march writes
U	buffer (read, f32)	camera, volume placement and march settings

U carries the inverse view-projection, the volume's world transform, the step count, density and emission gains, and the target's inverse size.