UE4 still does not have any proper way to do tinted glass

[Rawalanche]

@Manoel.Neto

From what I understand, you want tinted glass to be rendered in a single pass, without resorting to using sceneTexture. To do tinted glass, you need to modulate the pixels behind the glass by a RGB value and add the reflected light/environment from the glass surface. There is no GPU blending mode that can do color modulation and color addition at the same time, therefore your request is impossible at the hardware level(*): you need to do it in two blend passes (first modulate, then additive).

(*) There are ways to do it on certain hardware: raytracing (RTX only) and tile-based mobile GPUs actually allow in-shader blending. There’s also an optional feature on some shader model 5.1 GPUs that allows in-shader blending, at a cost.

So? I don’t really care/mind about how many blend passes it takes. I mean for example Unreal already does one draw call per every material slot on a mesh. That’s like saying it’s impossible to have meshes with multiple materials on GPU because you can’t do multiple materials in a single draw call. It may not need to be so efficient that it happens on the GPU shader level under the hood, that’s not the priority here. Priority is just acceptable workflow from user experience standpoint.