Autodesk has added a Phenomenon wrapping the shader, and it was just discovered there is a typo in the Phenomenon declaration, that causes one of the parameters to not actually function. The blur still works - but only with a fixed level. The checkbox for inheriting the blur from the Arch&Design material is non-functional!
You can easily fix this yourself by opening a file named "architectural_max.mi" which in the path: <3dsmax>\mentalimages\shaders_standard\mentalray\include.
Opening the file you can search for a line which reads like this:
"mia_material_blur" = interface "not m.mia_material_blur",
Edit this line to read:
"mia_material_blur" = interface "m.mia_material_blur",
...i.e. removing the "not ".
Now, all parameters of your environment blur (including inheriting blur from the Arch&Design material) should work!
Also, some people report issues with flickering in the reflections. This can be caused by two things:
- Too low resolution in the Envblur shader. The "resolution" value need to be high enough to resolve details in the original environment map.
- Intermittent interaction with the "blur" feature in 3ds max "Bitmap" shader. Turn down the blur in the Bitmap shader (in the "Coordinates" rollout) to lowest possible, which should resolve the problem.