Motion blur evaluation

[bartolos]

Hi,

Looking over the console output - I can see the exporter is sampling temporally at whole frames and in-between (of course depending on how many time samples per frame are selected in the render settings).
Say - for example - with my current settings (1 time per frame, shutter half FPS, shutter alignment BEFORE) when rendering frame 15, it exports time samples at frame 14, 14.5, 15.

My question is: Is it possible to somehow set the sampling to occur at frames: 14.5, 15, 15.5 ?
I tried different shutter-alignment and time-shift settings but the change happens only on the mid-frame sample - i.e. 14, 14.8, 15, etc.

Also it would be very convenient having a possibility to disable motion blur caching for specific Octane ObjectTags when sequence rendering. Right now I had to work around this by writing a script that keeps rendering single frames one by one separately, which is sub-optimal at least.

Cheers,
B

[aoktar]

Mblur shift can provide this but cannot confirm without spending time on. One thing that has to calculate frame for current time, others should be shiftable. But great you solved the logic which is behind of that.

Second, objecttag->motionblur=none. At this option, plugin will not export any key frames for current object and this means no motion blur for that.

[bartolos]

Thanks for so fast response!

I am sorry I was not clear in explaining my intention - my wish is to disable only the motion blur cache on specific objects - like force recalcucate...

Please let me explain how i see this:

Right now when rendering animation frames with object with vertex motion it is like that:

Frame 1:
Calculate object shape for frame 0
Calculate object shape for frame 0.5
Calculate object shape for frame 1
*RENDER*
Frame 2:
Reuse shape from frame 1
Calculate shape for frame 1.5
Calculate shape for frame 2
*RENDER*
Frame 3:
Reuse shape from frame 2.... and so on.
I understand this is efficient for most cases and saves calculation time...

My hopeful wish is:
1. to have setting on ObjectTag to force calculate on every animation frame (do not reuse motion blur from previous frame)
2. to have ability to adjust time offset for calculating shape of objects, i.e. at frame 5 - get object geometry at frame 4.5, 5, and 5.5

To explain why:

For example: Realflow mesh loader plugin is keeping consistent vertex count in-between frames - i.e. time segment between frames 4.5->5.49999 has consistent vertex count, and there is motion on vertices added.

Also: for scenes with jerky camera-tracked motion (like handheld footage) whole-frame motion blur calculation (even when using fast shutter) causes fast movement to become smoother (spikes in f-curves get averaged out) which causes CG elements for float over original footage. Right now my solution is to render without motion blur and add fake motionblur in compositing (and it looks so much worse). If it was possible to time-sample at - i.e. frame 4.9, 5, 5.1, the motion smoothing effect would be less noticeable. Again I understand this is a special case and would be low priority on the big wishlist.

Cheers,
B