Why does VrayDistanceTex affected viewport performance?

[GeraldW]

Hey everyone,

can anyone explain why the VrayDistanceTex affects the viewport performance, even when it doesnt show in the viewport?

Demostrating this on a basic test scene with a default plane and sphere.
The plane has a VrayMtl and i picked the sphere inside VrayDistanceTex.
Viewport Shading is set to Standard.

Test Scene and screenshot in the next post.


FPS differences when moving the sphere:

120 FPS (not connected at all):



90 FPS:
It even affects the viewport if its not connected to the shader (2.image)





40 FPS (VrayCompTex):


7 FPS:




I´ve attached the demo file as well.

Thanks!

[GeraldW]

Screenshot and attached max file:

[hermit.crab]

No issues on my end. Usually, VRayDistanceTex slowdowns occur when there are many objects in the scene (it assesses all of them), hence why we implemented a "Compute in viewports" checkbox to avoid that. Otherwise, I noticed you were using a very outdated version of V-Ray. Does it happen if you update?

[GeraldW]

Thanks for your reply.
I just tested the file with the newest 3ds max and Vray version. The slowdown still occurred, BUT turning the "Compute in viewport" off and on again fixed it.

Also I have to admit, I didn´t know there is a "Compute in viewports" checkbox. I only need it at render times so, I can easily turn it off for now.

Thanks for the help!