ssgi.renderFeature

The gather, the filter and the composite — three compute passes plus a blit, all at afterLighting.

order	pass
30	ssgi_gather — form-factor sum over nearby pixels into ssgi_raw (rgba16f)
31–34	the à-trous filter from @builtin::systems.denoising.denoiser
35	ssgi_apply — scene + albedo * irradiance * intensity
36	blit the composited result back over the scene

The gather reads @scene.color, @scene.depth, @scene.normal and @frame.camera; the composite also reads @scene.material. All of them resolve against the render target being drawn, so the result is correct in offscreen captures and RTT cameras at their own resolutions.

@scene.normal and @scene.material are the deferred G-buffer, so this needs the deferred path (the default).

Parameters arrive through the ssgi_params buffer, packed by @builtin::systems.screenSpaceGI.screenSpaceGI.