DRD Team

The "restart" ccmd allows you to change which game you are changing - or more importantly, what the contents of your PLAYPAL lump contains. The Palette Tonemap shader does not yet account for this, however. For example, you may start the game with Heretic, but then restart with Doom - as shown in the screenshot.

Damn it, thought it was safe to just generate the LUT texture first time needed and then keep it. Are there other ways the PLAYPAL lump might change besides with a restart ccmd?

No - the only way to change it is when GZDoom is willing to open new files, and that's at the beginning of the game or through a "restart" - afaik.

Pull request fixing this: https://github.com/coelckers/gzdoom/pull/88