MDL graph and Iray renderer features are missing
End of life
MDL graphs and the Iray renderer were both removed in version 16.0.0 of Substance 3D Designer.
For photorealistic 3D renders, you may use our GPU Pathtracer renderer. This renderer is developed in-house and will be progressively rolled across Substance 3D applications.
Regarding MDL support, it is being removed a part of Substance 3D moving forward with MaterialX as its shading language of choice for interchangeable, widely-supported material definitions.
Version 15.1.3 is the last version of Designer with support for MDL graphs and the Iray renderer. Users of that feature should therefore not update to higher versions.
The documentation for these features is still available here:
recommendation-more-help
dd48abc6-e399-43d2-9777-578ec70c5a23