[SHELVED] Material Layering Feedback for 4.19

[MDiamond]

@.Bunner

Hi MDiamond, that was the channel mask parameter. I added it to help the common operation of picking a single channel from a texture or color which comes up a lot with layers and we noted many cases ended up using static component masks for this. As each of those added potentially introduces a new permutation we wanted a cheaper alternative that allowed better re-use of materials, especially with an instance heavy workflow. Can you please go into a little more detail of how the addition would work?

Internally that node wraps up a vector parameter and a dot product to pull out the channel data, so in that case a black value of 0 would always return 0 i.e. no mask. I could see that having it’s uses to blend something out but if you have any good use-cases it would be nice to better understand the potential here.

Thanks for all the feedback so far everyone!

I have to dig an example of using a black ID, for now I guess its easier to educate my team to start painting Material Masks starting with the black color so the bottom-most material will be in black areas and each subsequent layer is read from the next channel.

I did however found an example of when adding masks from two channels could be useful. In the pics bellow, the chair fabric is two tone, and when blending materials, I’m selecting two channels to the fabric part, but then I’m using the Override Base Color and selecting just one of the channels.

This keeps my tiling, roughness etc values the same and makes me not pay the instruction cost of adding another fabric layer and using the same parameter values as the first fabric layer. I guess for weird exceptions I will make my own blend function that allows dot products of more channels at once, which is the beauty of the current implementation as I see it, unless there’s a better way to handling cases like that.