motion blur on animated vray sun?

[tzaar]

Hello!

I fear that this is a really stupid question, but I just can't get motion blur on the shadows of an animated daylight system.
I'm making a sped up/timelapse daylight study in a room. 24 hours in 240 frames. The sun is the only thing moving, and I just can't get motion blur, both with old phys cam and the new 2016 one. So I tried an animated box moving trough the room, to make sure I wasn't missing anything obvious, and that one does indeed get motion blurred.
Should I just render more frames and frame blend in post?

I'm on Max 2016 and vray 3.2 (will try to move our team up to 3.3 in the coming week, sorry if this is a fixed issue that I have missed in the change logs I've read)

Cheers!

[Zdravko.Keremidchiev]

Strangely enough the VRaySun can't seems to produce MB effect. I reported the issue to the developers.

[tzaar]

Ok, thanks for the reply! Thought I was making some noob mistake.
And I tried in 3.3 now and it's the same. Strange that this has not come up before, there must be lots of archviz guys that have tried to make a sped up daylight animation.

[vlado]

Well, you can always render intermediate frames and blend them to get the blur... you can render them at lower quality because the blend will reduce the noise.

Best regards,
Vlado

[vlado]

...or use the "multipass" motion blur in 3ds Max (although that only works with a standard camera).

Best regards,
Vlado

[tzaar]

I thought of rendering and blending intermediate frames, but would not have thought of lowering quality to speed things up. Good idea, thanks!