This is a nasty bug I fought a lot against while redoing the lighting of arachind2.
I noticed that sometime that lightmap may be repainted over glow map, notice how the neon is not entirely white:
And if it's a lot of white, it's thanks to a lot of time lost to adjust the light emitting shader backlight…
So I found the issue, it's occurring when there is both a diffuseMap stage and a legacy lightmap stage (in the form { map $lightmap … }, in this case the lightmap is painted twice: over the diffusemap and before the glow map (implicit lightmap stage that goes with diffusemap), and then over again with the explicit legacy lightmap stage.
This is how it must look:
Notice how the whole lighting is more brighter and does not have the same colour, meaning the lighting was initially done against a bug and is not anymore what was wanted to be (the outside has a cold blue light and the blue color was intentional to produce that cold feeling).
This is a nasty bug I fought a lot against while redoing the lighting of arachind2.
I noticed that sometime that lightmap may be repainted over glow map, notice how the neon is not entirely white:
And if it's a lot of white, it's thanks to a lot of time lost to adjust the light emitting shader backlight…
So I found the issue, it's occurring when there is both a
diffuseMap stageand a legacy lightmap stage (in the form{ map $lightmap … }, in this case the lightmap is painted twice: over the diffusemap and before the glow map (implicit lightmap stage that goes with diffusemap), and then over again with the explicit legacy lightmap stage.This is how it must look:
Notice how the whole lighting is more brighter and does not have the same colour, meaning the lighting was initially done against a bug and is not anymore what was wanted to be (the outside has a cold blue light and the blue color was intentional to produce that cold feeling).