Repository navigation
Fix pathtracer double-counting ambient light - #642
Open
stefanatwork wants to merge 1 commit into
Open
stefanatwork wants to merge 1 commit into
stefanatwork wants to merge 1 commit into
Conversation
Skip ambient lights in next-event estimation since they are already added when rays escape the scene. Fixes #491. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
stefanatwork
force-pushed
the
fix-pathtracer-ambient-double-count
branch
from
October 23, 2026 08:57
81398c8 to
49e89ce
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #491.
The ambient light was added both when rays escape the scene and via next-event estimation in the per-vertex light loop, with no MIS weighting, so it was counted twice (~2x too bright; a diffuse plane with albedo 0.25 under unit ambient rendered 0.498 instead of 0.25).
This skips
LIGHT_AMBIENTin the NEE loop in bothpathtracer_device.cppandpathtracer_device.ispc; the escape branch still accounts for it.