When rendering with the BiDir engine and with transparent film selected, the background is displayed only half-transparent.
Saved images appear to be correct.
There is some mention in the code about "pre-multiplied" alpha (or more specifically, not applying it due to what Blender expects). Might be a good starting point for review what Blender expects currently, but also why BiDir and Path produce different results when seemingly RGBA data is identical.
Edit: This bug was already present in v2.10.2 and Blender 4.5
When rendering with the BiDir engine and with transparent film selected, the background is displayed only half-transparent.
Saved images appear to be correct.
There is some mention in the code about "pre-multiplied" alpha (or more specifically, not applying it due to what Blender expects). Might be a good starting point for review what Blender expects currently, but also why BiDir and Path produce different results when seemingly RGBA data is identical.
Edit: This bug was already present in v2.10.2 and Blender 4.5