Hello SideFX,

I think I found a bug where multiple shaders are not able to layer when using two Mtlx Mix nodes.

Here's the situation:

I'm creating a large environment that features salt flats:

And I want to add some snow on top of these mountains using a layered shader approach.

At the moment, I am accomplishing the transition between the salt / mountain areas using a Mtlx Mix node:

The mix is determined by a point attribute that is set in SOPs.

When I try adding another mix like this, everything will render white no matter what I do. In this example, I tried troubleshooting it by making my snow shader red. As you can see, it will revert to a white color no matter what:

As far as the mix attribute goes, I checked on this in SOPs as well:

And I double checked the signal with an unlit shader to make sure this information came through.

So... I'm pretty sure that this situation is bugged. Is there any other alternative that I can use to layer on a snow shader in the meantime?

I don't have time to upload the scene file, but I'll make sure to add a bug report.


Thanks,

- Tyler

Attachments:
saltFlatsTest_v5.jpg (261.6 KB)
saltFlatsTest_v6.jpg (52.2 KB)
saltFlatsTest_v7.jpg (149.5 KB)
saltFlatsTest_v8.jpg (128.0 KB)
saltFlatsTest_v9.jpg (138.7 KB)

Attachments:
Screenshot 2023-12-01 183856.png (149.3 KB)
Screenshot 2023-12-01 183707.png (885.4 KB)
Screenshot 2023-12-01 192232.png (642.6 KB)

sniegockiszymon
Yeah but you can mix those different diffuse/roughness etc before pluging them into shader. For exmaple I'm creating here blending between image textures (3 red nodes, for albedo,rgh and disp) with my second, procedural ice material, and everything is mixed before pluging them into one shader (because it has transmission it wasnt that easy, but its for another topic) generally mixing shader is good for "hard" transitions, like leafs and branches etc but when values are between 0-1 mixing shaders might work strange. The biggest advantage of mixing shaders is when you have to mix different ones (then its really only option) but if you are using everywhere standard surface then there is no need for blending shaders.

Ahh okay I gotcha. Thanks for sharing, I'll use that trick for getting around it. I usually go about it by doing this sort of thing in Redshift because it avoids a pileup of nodes:

But, I set up Karma in the way you mentioned, and it's looking great now.

So thanks again for the help!


Have a great day,

- Tyler

Attachments:
saltFlatsTest_v10.jpg (37.7 KB)
saltFlatsTest_v11.jpg (242.5 KB)