Someone have this warning after instancing aiVolume?
Render start is very long, any suggestion?
# Warning: aiVolume1Shape: could not set BOOL parameter "disable_ray_extents"
That warning is for a parameter that was removed from the Arnold Volume node. You'll get that warning as soon as you create a Volume node in Maya, because MtoA still tries to set the parameter.
It won't affect instancing or how long it takes to render.
I tested a scene with thousands of volume instances, and I didn't see any slowdown on scene initialization.
If you can post an Arnold (with verbosity = Info) we can where the time is being spent.
For the error I guessed that this attribute is no longer there, the question only remained why it is still in the attributes of the container.
For the instance I use soup development instance manager with 50000 instances aiVolume, in mtoa 3.0.0.2 render start more longer then in mtoa 2.1
But I think question feels closed