Probe captures: deferred opaque path (G-buffer + base lighting at probe resolution) #833

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opened 2026-10-17 22:16:24 +00:00 by sky_line · 1 comment

sky_line commented

2026-10-17 22:16:24 +00:00

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Plan

Opaque probe-face geometry goes through the G-buffer FS (#813, 48 registers) into small per-face G-buffer targets (128 px; a few MB for six faces).
Then a #827-style base lighting pass (72 registers) at probe resolution, with local lights from the probe's own list (nearest-N, as #829).
Alpha stays forward (capture FS).

Benefits:

lower registers / higher occupancy for the bulk of capture shading;
one lighting implementation for probes and the main view (no drift between the two).

Measure

GTX 1080 at 4K, high: capture shading pr_face + pr_rt_face is ~1.5-1.7 ms today. Expected 0.5-1 ms gain. Plus a probe image A/B against the forward path. Do this after the probe-cull sharing ticket.

Probe captures run the forward path per face (capture FS 142 registers on a GTX 1080 after #829). LL / Firestorm capture probes through their deferred pipeline (G-buffer + deferred lighting at probe resolution). ### Plan - Opaque probe-face geometry goes through the G-buffer FS (#813, 48 registers) into small per-face G-buffer targets (128 px; a few MB for six faces). - Then a #827-style base lighting pass (72 registers) at probe resolution, with local lights from the probe's own list (nearest-N, as #829). - Alpha stays forward (capture FS). **Benefits:** - lower registers / higher occupancy for the bulk of capture shading; - one lighting implementation for probes and the main view (no drift between the two). ### Measure GTX 1080 at 4K, high: capture shading `pr_face` + `pr_rt_face` is ~1.5-1.7 ms today. Expected 0.5-1 ms gain. Plus a probe image A/B against the forward path. Do this after the probe-cull sharing ticket.

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2026-10-17 22:16:24 +00:00

sky_line added this to the Slipstream project

2026-10-17 22:16:24 +00:00

sky_line referenced this issue from a commit

2026-10-22 19:32:55 +00:00

VK probes #833: deferred opaque path for probe captures (RenderVKProbeDeferred)