I have a offscreen scene that is rendered into a texture that is used as background in a lemur Panel using QuadBackgroundComponent. I would like to have only the rendered object on this panel, the rest should be transparent. I thought setting the alpha to 0 of the ViewPort, but it didn’t change anything:
Hmm - I still have an issue here. And maybe someone has a hint
As written before, I removed the FXAAFilter from the offscreen view. Since doing this, the background is transparent, great! But some parts of my model are now transparent as well. There are two materials on this model, both are pbr. One has the BaseColor set to a color, and this is displayed correctly (opaque). But the other one uses the BaseColorMap with a texture and its completely transparent. First I thought its about some alpha values of the texture, so I replaced it with a generated one using ImageRaster with an imageFormat Image.Format.RGBA8 and only the color ColorRGBA.Blue to ensure no bad alpha values, but it didn’t change a thing.
I am pretty sure I am doing something wrong and I know its hard to give any hints without having a testcase, but maybe someone has some direction nevertheless.
@Nehon: Its somehow PBR related, so maybe you have an idea?
Edit: If I enable the FXAAFilter again, I get a completely fine “blue” model - but then the background is black instead of transparent again…
My problem was fixed after setting the Color for BaseColor in addition to the BaseColorMap. I am not 100% sure but I think its because the shader takes the color information from the map, but the alpha gets multiplied by the basecolor anyway which results in 0 if there is no BaseColor set: