[Epic] RT denoiser (shadows, AO, GI)

sky_line commented

2026-09-27 05:44:58 +00:00

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Goal: one reusable denoiser for 1-spp ray-traced signals: shadows (per light or aggregated), AO, diffuse GI (and later reflections).

Approach

SVGF / ReBLUR-style: temporal accumulation (reprojection via motion vectors, history length, disocclusion reset from depth+normal) -> variance estimate -> edge-aware à-trous spatial filter guided by the thin G-buffer. Separate signal inputs so AO/shadow/GI can share passes but keep distinct parameters.

Children

Temporal accumulation pass (shared).
Spatial à-trous filter (normal/depth/luminance weights).
Hook RT projector shadows: move shadow evaluation to a per-pixel visibility buffer for the top-N lights (or stochastic light selection) so it can be denoised; lit pass reads the filtered visibility.
Debug views (raw vs denoised, history length).

Size: M-L. Depends on: Temporal epic items 1, 2, 4, 6.

**Goal:** one reusable denoiser for 1-spp ray-traced signals: shadows (per light or aggregated), AO, diffuse GI (and later reflections). ### Approach SVGF / ReBLUR-style: temporal accumulation (reprojection via motion vectors, history length, disocclusion reset from depth+normal) -> variance estimate -> edge-aware à-trous spatial filter guided by the thin G-buffer. Separate signal inputs so AO/shadow/GI can share passes but keep distinct parameters. ### Children 1. Temporal accumulation pass (shared). 2. Spatial à-trous filter (normal/depth/luminance weights). 3. Hook RT projector shadows: move shadow evaluation to a per-pixel visibility buffer for the top-N lights (or stochastic light selection) so it can be denoised; lit pass reads the filtered visibility. 4. Debug views (raw vs denoised, history length). **Size:** M-L. **Depends on:** Temporal epic items 1, 2, 4, 6.

sky_line added this to the Rendering: temporal + RT effects milestone

2026-09-27 05:44:58 +00:00

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2026-09-27 05:44:58 +00:00

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2026-09-27 06:34:26 +00:00

[Epic] Emissive surfaces as light sources (RT emissive lighting) #91

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2026-09-29 22:12:39 +00:00

Ray-traced sun and moon shadows (RenderVKSunShadows 2) #185

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2026-09-30 03:15:29 +00:00

RT: opacity micromaps (VK_EXT_opacity_micromap) for hardware alpha-tested shadows, shader alpha-test fallback #194

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2026-09-30 03:17:38 +00:00

RT sun shadows: further optimization (shadow-mask pass, reduced-rate tracing, hybrid edges, denoise) #195

sky_line added this to the Slipstream project

2026-10-06 15:04:15 +00:00

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2026-10-09 08:54:49 +00:00

sky_line commented

2026-10-09 22:37:02 +00:00

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Child 2 (spatial a-trous filter) + child 4 (debug views) done for the RT shadow mask: c83c0ac0d6 (RenderVKRTShadowAtrous, RenderVKRTShadowDebug 1-5; off by default). Lands in 1.2.0 Beta 8. Remaining: temporal accumulation, per-light visibility for projectors, AO / GI inputs.

Child 2 (spatial a-trous filter) + child 4 (debug views) done for the RT shadow mask: c83c0ac0d6 (RenderVKRTShadowAtrous, RenderVKRTShadowDebug 1-5; off by default). Lands in 1.2.0 Beta 8. Remaining: temporal accumulation, per-light visibility for projectors, AO / GI inputs.

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2026-10-09 22:37:02 +00:00

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2026-10-09 23:19:24 +00:00

TAA / FSR: shadow edges move / settle when an animated avatar part (e.g. a wing) passes in front of them #608

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2026-10-10 03:31:53 +00:00

Refs #85: SVGF-style a-trous spatial filter + debug views for the RT shadow mask

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2026-10-10 03:31:53 +00:00

Refs #85, #608: SVGF-style RT shadow history + variance-driven a-trous (RenderVKRTShadowSvgf)

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2026-10-10 03:31:53 +00:00

Refs #85: RT shadow fast-history box always brackets the accepted taps' fast means

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2026-10-10 03:37:42 +00:00

RT shadows: foliage shimmers under FSR with the half-res shadow mask; full res fixes it but costs ~1.3 GB at 4K #625

sky_line commented

2026-10-10 05:33:01 +00:00

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Sun-shadow part is done and owner-verified: SVGF-style temporal history + variance-driven a-trous for the RT shadow mask (c83c0ac0d6, 7074b8109f, 9592885200), wing-flap artefact #608 fixed. Shipped in 1.2.0. Remaining and not started: per-light visibility for projectors, and AO / GI inputs (#86). Nothing is being worked on right now, so this moves from In Progress to To Do.

Sun-shadow part is done and owner-verified: SVGF-style temporal history + variance-driven a-trous for the RT shadow mask (c83c0ac0d6, 7074b8109f, 9592885200), wing-flap artefact #608 fixed. Shipped in 1.2.0. Remaining and not started: per-light visibility for projectors, and AO / GI inputs (#86). Nothing is being worked on right now, so this moves from In Progress to To Do.

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2026-10-10 05:33:01 +00:00

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2026-10-10 11:24:19 +00:00

[Epic] Ambient occlusion tiers: GTAO (screen-space, replaces SSAO) + ray-traced AO (RTAO) #86

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