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Motion Blur Vertex limitation

Posted: Sun Oct 04, 2020 11:35 pm
by Raoul
Hi Aoktar,

I've run into a bit of a problem and would love some clarification.


im trying to achieve these "motion trails" in Octane
Image

this works on simple transform motion.. in that you'll get proper curved trails... but unfortunately doesn't work with any vertex animation.. ( ie an animated character)
instead it only ever draws straight blur lines. You do get a motion blur effect but it just doesn't accurately follow the curve of the movement of the object..

I've obviously tried pushing up the 'time sampling per frame' but it has no effect on this problem. ( object also set to transform/vertex in its object tag)


I've included a very simple scene to explain the problem.. a simple tall pole bending 180ยบ.
Instead of getting a nice soft curve following the top of the pole you just get a strange straight line following it. Which is obviously inaccurate.
( theres also a cube bouncing around which does properly have a motion curve... but i assume as its just transform data.. not vertex movement. )
test.mov
(4 MiB) Downloaded 2697 times
MOTION_03.c4d.zip
(77.44 KiB) Downloaded 158 times


Its a pity because you can do some really beautiful things with motion blur when it accurately follows an objects motion. ( particularly human motion)


So my questions are:

Am i doing something wrong?

Is this problem contained to the C4D plugin? Would it be fine in the standalone?

Is it a bug or something more complicated?

Can it/will it be fixed?

Re: Motion Blur Vertex limitation

Posted: Mon Oct 05, 2020 1:48 pm
by aoktar
I'm testing the case with my scene, your scene is not containing the mesh. Nevermind it's ok!

Re: Motion Blur Vertex limitation

Posted: Mon Oct 05, 2020 11:11 pm
by Raoul
Awesome, thanks Aoktar! Very much appreciated. let me know if you want me to resupply an example.
thanks
R

Re: Motion Blur Vertex limitation

Posted: Tue Oct 06, 2020 6:49 pm
by aoktar
Raoul wrote:Awesome, thanks Aoktar! Very much appreciated. let me know if you want me to resupply an example.
thanks
R
I'm still on to discover the reason of problem. Will let you know.

Re: Motion Blur Vertex limitation

Posted: Tue Oct 06, 2020 9:39 pm
by Raoul
Great, thanks for letting me know. Would be a great thing to get working as it opens up a lot of interesting visual possibilities. Will stand by.

Re: Motion Blur Vertex limitation

Posted: Fri Oct 09, 2020 12:09 am
by Raoul
Hi Aoktar,
Just wondering if you'd made any progress on this? Were you able to replicate the problem?
any thoughts would be much appreciated.
thanks
R

Re: Motion Blur Vertex limitation

Posted: Fri Oct 09, 2020 5:58 am
by aoktar
Raoul wrote:Hi Aoktar,
Just wondering if you'd made any progress on this? Were you able to replicate the problem?
any thoughts would be much appreciated.
thanks
R
Yes I can confirm that's not working across our expectations. And cannot find a way to fix it from plugin. Need to get some answer from core team

Re: Motion Blur Vertex limitation

Posted: Sat Oct 10, 2020 12:11 am
by Raoul
Thanks for the update! Sorry i don't use the stand alone.. was just curious is this a problem across all versions of octane or just the Cinema Plugin?

Would it be of any use for me to bring this up with Jules?

In essence it is a pretty fundamental feature, as in even less extreme motion blur situations it'd be creating inaccurate results (Basically all character animation). As Octane prides itself on being an unbiased ad accurate render it seems a worthwhile thing to get right.

Really appreciate your help on this Aoktar!
thanks
R

Re: Motion Blur Vertex limitation

Posted: Tue Oct 13, 2020 2:36 pm
by monomagnus
This might be related, but Octane Motion Blur isn't working as expected in one of my projects containing a lot of particles as well.

It worked when I first set it up, but when I cranked the number of particles the motion blur suddenly just disappeared.
There's a time shift when I enable/disable it that indicate some time calculation is going on, but no actual blur.

Project file : https://www.dropbox.com/s/6ew1kj9siej3p ... e.c4d?dl=0

UPDATE : I got my motion blur back when I deselected the Motion Vector Info Pass.

Re: Motion Blur Vertex limitation

Posted: Wed Oct 14, 2020 7:16 am
by bepeg4d
monomagnus wrote: UPDATE : I got my motion blur back when I deselected the Motion Vector Info Pass.
Yes, this is how it works, if you enable the Motion Vector pass, it means that you want to obtain the motion blur in compositing, over a non motion-blurred frame.

ciao Beppe