I have a really hard time trying to get a satisfying result of motion blur on some bird wings. Each flap is about 4-6 frames from up to down and back up again.

However I set my motion blur settings I cant really get nice long motion blur without it overshooting and making the wings look way longer than they actually are. Any tips?

I'm using Geometry Velocity Blur with Trail SOP. And increasing the Geo Time Samples doesńt seem to make any difference at all.

Have you tried multisegment deformation blur instead of velocity blur?

G

keyframe
Have you tried multisegment deformation blur instead of velocity blur?

G

No I have not, but it sure sounds interesting. How does that work and how do I set it up?

Have a look here:

http://www.sidefx.com/docs/houdini10.0/rendering/motionblur [sidefx.com]

G

keyframe
Have a look here:

http://www.sidefx.com/docs/houdini10.0/rendering/motionblur [sidefx.com]

G

I've read through that one a couple of times before and sadly I can't get anything close to what I want anyway. I guess I'm missing something. The oversampling documented there seems to regard several samplings per frame. I would probably want the opposite (however unrealistic it may be).

I've attached a scene which a MUCH simplified setup which is similar to my original one which perhaps could help find some fault in my settings. As seen in the picture I can't seem to get any motion blur longer than that one, at least not without making it overshoot. And with motion blur as in the pictures it looks unrealistic and unsmooth.

And with motion blur as in the pictures it looks unrealistic and unsmooth.

Based on your file, everything seems legit. Note though, that your wings tips are travelling in a straight line – so that's all that blur that you can expect to get.

Perhaps you could illustrate using an image what you are after?

Reading between the lines, you may be after a blur of a longer time segment
ie: render frame 1 as if 10 frames have gone by. If that's the case, then you need to adjust your shutter parameter on the sampling tab of your camera.
At the moment it's goal is to blur for 0.5 the frame. You'll obviously need more subsamples (geo, or v) in your rop as well

G

keyframe

At the moment it's goal is to blur for 0.5 the frame. You'll obviously need more subsamples (geo, or v) in your rop as well

I must have misread the documentation of that parameter before. Or just assumed that that parameter controlled when on the frame the shutter opened, like 0.5 = the middle. Why I got that strange idea is a mystery but I'll try to experiment with it a little tomorrow when I get back to work. Thanks in advance!