Multiple Channel Use in Texture Sample [Exposed in Instances]

[antonowski]

@.Bunner

4.19 added a new material node that should help here, the Channel Mask Parameter. Just realized this didn’t give an visual example in the release notes, but it’s something like the following:

https://mail.google.com/mail/u/0/?ui=2

Note how the mask channel value is set to green, so it pulls the matching data (in this case the quads containing data in the green channel).
Internally it’s just a wrapper for a vector parameter, so you can swap it at runtime or in an instance without creating a new permutation:

https://mail.google.com/mail/u/0/?ui=2&ik=a70827d74b&view=fimg&th=15fe0416ec06433c&attid=0.3&disp=emb&realattid=ii_15fe0351030f7ab7&attbid=ANGjdJ-XfRD8si2Eb_lYc_blgMX68rFZmk5jjpGhNXMpr6YUVOjIvz-zfGTW-fXzUgyaL_Qvj39zKDRMlyMNRoPZaWZsJ0ACmfGoOBUT2XyIYYerzgmMx4vSvQRVvp0&sz=w1088-h402&ats=1521566862930&rm=15fe0416ec06433c&zw&atsh=1

If you don’t want to update engine version, you can do the same thing with a vector parameter going into a dot product, just set the vector to the color of the channel you want to extract. This was introduced primarily to help with material layers where masks and blends are reused and we need to avoid compiling a separate shader for every variation.

Hey! Thanks for the reply.

Yeah, we’re not currently able to upgrade to 4.19 so what you suggested at the end there might be the better option.

This should make things a lot less complicated for our other artists, so thanks again!

This has led to another problem I’m finding with Mesh Decals (of which I’m sure you’re fully aware) - Mesh decal visibility is clipping through other meshes when using the deferred decal shader type and unfortunately there’s no way to resolve this short of using a translucent material type for mesh decals instead. That’s fine, but do you know if there’s a way to have a translucent material not be super bright even in shadows without simply reducing its opacity?

If I could figure that out, I’m sure we could stick with separate master materials for mesh decals and deferred decals as the limitations of each don’t cover both meshes and decal options.

Many thanks again!