Fix #22574: fix volumetric fog back-face intersection artifacts#23588
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joaoconceicao12 wants to merge 2 commits intobevyengine:mainfrom
Open
Fix #22574: fix volumetric fog back-face intersection artifacts#23588joaoconceicao12 wants to merge 2 commits intobevyengine:mainfrom
joaoconceicao12 wants to merge 2 commits intobevyengine:mainfrom
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…acts Fixes angle-dependent volumetric fog artifacts in the atmosphere example (shadow flipping and hard edges while rotating the camera). Root cause was inconsistent back-face intersection setup: far-plane construction in CPU code and ray-plane intersection in WGSL shader code. This patch corrects both calculations and adds a regression test for far-plane positioning in volumetric fog (get_far_planes). Signed-off-by: João Conceição <joao.conceicao@tecnico.ulisboa.pt>
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Follow up target branch correction from PR #23406 |
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Objective
Fixes #22574.
This PR fixes angle-dependent volumetric fog artifacts in the atmosphere example ([--features free_camera], where rotating the camera caused shadow flipping and hard edges.
Solution
The root cause was inconsistent back-face intersection setup between CPU and shader paths:
CPU side: far-plane construction for fog volume traversal.
WGSL side: ray-plane intersection math.
This PR:
Corrects far-plane setup in the volumetric fog CPU path.
Corrects the WGSL ray-plane intersection calculation.
Adds a regression unit test for [get_far_planes]) to prevent this from regressing.
Testing
cargo test -p bevy_pbr --lib passes (including the new regression test).
Manual visual test:
cargo run -r --example atmosphere --features free_camera
Rotating the camera no longer shows the previous flipping/hard-edge artifacts. (see video)
video1.mov
Platform tested:
macOS (Metal backend).
No additional untested platform-specific behavior is currently known.Fixes angle-dependent volumetric fog artifacts in the atmosphere example (shadow flipping and hard edges while rotating the camera).