The Neutral That Wasn't
WhiteBalance at its default now leaves your image untouched, instead of quietly tinting it green. And FXAA finally admits what it actually is.
Every color tool has a resting position, the setting where it promises to do nothing. For WhiteBalance that position is 6500 K, tint zero: the “neutral” preset you reach for when you want the node in your chain but not in your way. It was lying to you.
Drop a flat gray card through WhiteBalance at its defaults and the pixels came out a hair green and a touch darker. Not enough to notice at a glance, exactly enough to poison a grade you build on top of it. The two panels below are that gray card: left is the old default, right is the new one.
The cause was a mismatched pair of white points. The node adapts your image from a source white to a target white, and the target was computed from a color-temperature curve while the source was pinned to a hardcoded textbook value a few kelvin away. Two whites that should have been the same point were not, so the “do nothing” case did something: about a delta-E of 3, every frame, forever.
The fix is the kind that feels obvious in hindsight. Derive the source white from the exact same curve, evaluated at the exact same 6500 K. Now the two whites are the same point by construction, the adaptation math collapses to an identity, and the default is a true pass-through, byte for byte, on every GPU we run on. Nudge the temperature off 6500 and it adapts as before; sit it at neutral and it genuinely rests.
There is a test guarding it now, and the test does not trust a snapshot of our own output. It renders the same scene straight to the display and again through WhiteBalance at default, and demands the two be pixel-identical. A green cast cannot equal a clean frame, so the test cannot be quietly satisfied by a regression sneaking back in.
While we were being honest
FXAA got a smaller but related correction: it stops claiming to be something it isn’t. The node’s description advertised “FXAA 3.11,” the full reference edge-antialiasing algorithm with its edge-end search and all the trimmings. What ships is a lightweight seven-tap edge smoother. Good, cheap, fine for a still or a quick cleanup, but not the thing on the label. The description now says what it is, and points you at the temporal anti-aliasing on RenderScene when you’re pushing moving footage and want the sharper result. A tool that tells you its real strengths is worth more than one that oversells.