Using a substance inside a MDL network

[andrew.cirillo]

Hey, it's because you made some weird connections.
Did you watch the tutorials we made about MDL?

here is how you could set it:

Hi Vincent,
I did watch the tutorials. What exactly was wierd? Also, just to be clear I did not see the issue in substance designer, only externally when i tried to use the shader outside of SD. I tried just a basic fresnel setup as you have suggested here but I still saw the issue.

[Vincent Gault]

First I removed the metallic related nodes which are not useful in our case.
Then I changed the custom curve layer by a fresnel with an IOR of 1.5
Then the base color was plugged in the specular reflection as well.this is indeed weird that you still encounter the issue..

Are you sure you don't have any custom filters or tone mapping in the other application?

[andrew.cirillo]

Hi Vincent,
There are definitely no custom filters or tonemapping. I have checked with and without tonemapping and the problem is still present. As I mentioned the issue is not present in the latest release of iray that I have so the issue is most likely an iray issue. My only problem is that I need to use the older versions. I'll keep digging around and see if I can find a suitable workaround.

[andrew.cirillo]

Ok so I have identified what the problem is. If I am not wrong it is a combination of an iray bug and an issue with the baked map being output as 16bit regardless of what I have set the output per channel to.

Basically the older version of iray standalone seem to have issues with the 16bit texture. This issue has been fixed in the latest release.

Do you know if I can force the baked output for the substance to output an 8bit image rather than a 16bit image? I don't seem to be able to force this in the substance nodes, and not sure if this is actually a substance bug.

[Cyrille Damez]

Do you know if I can force the baked output for the substance to output an 8bit image rather than a 16bit image? I don't seem to be able to force this in the substance nodes, and not sure if this is actually a substance bug.

It is not a bug, but it can be confusing. The settings in the output node (for bit-depth, compression etc.) are only indications that are saved in the sbsar file for the integrations in third-party software (e.g. game engines) so that they know which format they should render the textures to. They are not used when exporting to bitmap files in Substance Designer. Currently the only way to export an 8 bit image is either to change the graph so that the node before the graph output has an 8bit result (e.g. by forcing to "absolute" and "8 bits"), or to export in a file format which does not support 16bpc.