Do transparent shadows work for PBR materials?

Questions
1

I have PBRMaterials with opacityTextures applied, with useBlurExponentialShadowMap, enableSoftTransparentShadow & transparencyShadow. I’m seeing the shadows for the mesh but it’s not taking into consideration the opacityTextures.

Do transparent shadows work for PBR materials or only standard?

Here’s a PG using PBRMaterial which doesn’t seem to work:
https://playground.babylonjs.com/#LKA8VM#4

And working StandardMaterial version:
https://playground.babylonjs.com/#LKA8VM

2

In more of a fair comparison, I made a version using StandardMaterial with transparency coming from opacityTexture rather than diffuseTexture.hasAlpha and that doesn’t work either.

https://playground.babylonjs.com/#LKA8VM#5

In my use case I have a single opacity texture applied to many different materials with opaque diffuse/albedo maps. It doesn’t make sense to add the same alpha channel to each of these instead of using a common opacity texture. It would incur too much additional bandwidth.

Is there a way to get transparent shadows working with opacityTexture in PBRMaterial?

3

By default the texture used to retrieve alpha data when generating the depth map texture is the diffuse texture. You can override the mat.getAlphaTestTexture function to use your opacity texture instead:

https://playground.babylonjs.com/#LKA8VM#6

1 Like
4

Thanks @Evgeni_Popov