[kami]

With another scene I notice a strange behavoir I did not expect, so I did some speed tests to show what I mean.
It is concerning objects being hidden from camera and masks.

The scene is an exterior building (not very large). Overall polygon count is 4.2 million (with instances disabled).
There is a small forest in the scene which I only needed for light and reflection purposes consisting from 134 (instanced) lowpoly trees. (= 1.8 mio polygons)
I let all of them run until SL5. Here are the different settings and results:

Normal Setup - instances disabled - no objects hidden from camera:
5m26s

Normal Setup - Instances enabled- no objects hidden from camera:
10m22s (that was what I was expecting)

Normal Setup - all trees hidden from camera:
instances off: 15m58s
instances on: 1h02m12s
this came very unexpectedly ... the same scene running 3 to 6 times longer, just because some objects are being hidden from camera


Mask tests:
Normal Setup - instances disabled - no objects hidden from camera - rendering channel always enabled besides the masks:
no masks (as above): 5m26s
minimal masks (alpha and materialID): 5m46s
multiple masks (alpha, materialID, objectID, z-depth, normals): 6m35s
shadow masks (just the shadow mask!): 9m13s
multiple masks (same as above+shadow): 10m13s
this was also a suprise to me, that the shadow mask alone slowed down the rendering by almost 50%

Is there a specific reason for both of these speed losses? Is this something that might be optimized for Maxwell v3?

[polynurb]

are you referring to as you write "hidden to camera" or "hidden"?
in rhino there are both options, and "hidden to camera" does only exactly that: objects are hidden from the cam, but are still calculated in all other respect(shadows refraction,etc.). So I would not expect any speed-up using hidden to cam at all.
It is unexpected though that it takes much longer with instances hidden than visible, seems like this is a rare case the engine is not very optimized for.

[kami]

yeah, I did not expect that huge time difference as well, even when instances are disabled.
I meant the "hidden to camera" because I wanted the shadows and reflections.