Strange Motion Blur Sampling

[Karba]

Thank you Karba! I know you are busy so I appreciate this. I know a majority of users may not benefit from this, but those of us pushing the renderer to its limits are!

I got your scene.
Unfortunately it is time precision issue of 3dsmax. you have very fast motion in very short period of time. So there is nothing I can do here. Try to increase motion duration and reduce the speed.

[profbetis]

I got your scene.
Unfortunately it is time precision issue of 3dsmax. you have very fast motion in very short period of time. So there is nothing I can do here. Try to increase motion duration and reduce the speed.

Oh, very interesting. I noticed that the animation graph looked strange inside Max as well when zoomed into to such an extent. Thanks for looking into this.

[profbetis]

I just realized that in the kernel settings I can set the motion blur duration to greater than 1.0, which totally makes my motion-blur based workflow way better. It also essentially fixes this problem.

[fellowla]

If that doesn't look wrong to you, I will post some stills from my current project to better illustrate the issue I'm having. But I keep running into the same issue where object with rotation that are moving in a straight line do not have proper motion blur. They have a weird curved motion blur.

You can see it in this picture I posted a few months back as well. The object is moving in a perfect straight line. no reason for the motion blur to look like that.

http://render.otoy.com/forum/download/f ... &mode=view

Are you expecting straight lines in motion blur of rotating objects? LOL

Hi Karba,

Sorry to reopen this case but i have the same issue of not understanding the behavior of this motion sometime.

I will think in a case of a sphere rotating on herself and falling down straight that yes the motion blur will look overall straight but the pattern/texture on it will look like it's rotating.

I render some spheres falling with some rotation on themselves to illustrate.

It seem like the overall trajectories of the spheres become "curvy", is it what it should look like ? (I'm using octane standalone 2.14)

I render the same alembic with another render engine in maya and the result look like straight lines and that what i was expecting so maybe the way octane is doing it is the good one but I just want to make sure again as i'm a little bit trouble by that

Let me know what you think,

Thank's,

Ben

To see it in motion: (password : "octane")

octane render with no motion blur
https://vimeo.com/113453836

octane render with motion blur, shutter 100%
https://vimeo.com/113453835

The other render engine with motion blur
https://vimeo.com/113453834

[gueoct]

Can´t watch it, because it is a "Private Video"......

[profbetis]

That's definitely very strange motion blur

[fellowla]

Can´t watch it, because it is a "Private Video"......

The password is "octane"

[voltaire585]

The octane version looks wrong. The motion of rotating spheres should be straight, unless you are not rotating around their centres. This could only occur physically if the spheres weight was not even. eg biased to a side.

[fellowla]

Yes, that's what I would think even if i don't have a physical explanation . I feel that it was the same problem for "bcravin", that why i posted here.
Making sure it was not coming from the alembic interpretation I did another test just with a simple sphere rotating around his center. The result is the same, some curved motion blur in one direction. (I render it with the maya plugin).

Here are the motion test video with the sphere - vimeo password: "octane"
- Octane with motion blur
https://vimeo.com/113662654

- Octane no motion blur
https://vimeo.com/113663093

- Other render engine with motion blur
https://vimeo.com/113664591

Ben

[Karba]

I can't reproduce the issue.
What kind of MB do you use? object MB or vertex one?
Could you send me a scene?
[email protected]