I cant get camera motion blur working using H19 and Karma.
Ive got motionblur enabled in the camera effects of the Karma rop.
In the camera node Ive tried setting Shutter Time to 0.5 and 1.0

No motion blur in the Karma render to mplay or disk.

Help!

Do you have a Cache LOP in your graph? If you don't try placing one and set it to "Rolling Window of Frames" and see if that helps.

Good Luck

Hi Andy_23,
Thanks for your suggestion.
My current scene is just an old style hip scene with geometry, lights and camera nodes.

I have not explored LOP networks.

I guess Im going to have to learn all that in order add a Cache Lop.

Blur on in your Geometry Nodes?

Hi HM,

Yup blur is on in the geometry nodes.
Thing is the only thing animating is the camera.

SideFX recently posted a video on how to enable motion blur with Karma. Watch the whole series to see how to migrate a scene to Solaris as well.

This is the video: https://www.youtube.com/watch?v=lrLcX-cQZNY [www.youtube.com]

WillA
Hi Andy_23,
Thanks for your suggestion.
My current scene is just an old style hip scene with geometry, lights and camera nodes.

I have not explored LOP networks.

I guess Im going to have to learn all that in order add a Cache Lop.

You won't get blur in karma without any time samples. Normally this is fine because cameras come from usd files with all the time samples, and not your hip file where there would only be one time sample in existence at any given time. In LOPs, the cache node exists to force creation of multiple time samples. Without this cache node, motion blur is not possible for cameras created in the scene.

The Karma ROP creates everything from in the scene. Unless it has a cache node inside, it will not have any motion blur. In the current version (19.0.455) of Houdini, it does.

Hi jsmack,

Im on version 19.0.383 so I will update to 19.0455 to simply get camera motion blur working.
However, this issue is good motivation for me to learn LOPs.

Thanks for the help.

makrotius
SideFX recently posted a video on how to enable motion blur with Karma. Watch the whole series to see how to migrate a scene to Solaris as well.

This is the video: https://www.youtube.com/watch?v=lrLcX-cQZNY [www.youtube.com]

makrotius thanks for the link it's focused-on Karma and motion blur.

Homing in on my issue.

Just want to add this:
If you have a calculated rotation (like an expression based on $F) the Karma ROP viewport will not render motionblur for that rotation. If it is keyframed, it will.

OneBigTree
If you have a calculated rotation (like an expression based on $F) the Karma ROP viewport will not render motionblur for that rotation. If it is keyframed, it will.

I don't see any issues with expressions
there are really no expressions in usd, so whatever you use to control the LOP node's parameters with, it will store just resolved values in usd and hence the value clip produced by Cache LOP should be identical and MB should not produce different results

the only issue can be the actual expression itself
be careful with $F as that's integer frame, use $FF to make sure your values are continuous

Hi;

I have a usda file that contains a camera with animated xforms. I can see the attributes on the camera are green, indicating that it's animated (and, of course, when I scrub the timeline, I can see it moves).

However, I cannot seem to get camera motion blur going, and can't understand why. My Reference node that imports the USDA camera does not have a little watch icon next to it; I'm unsure whether this is significant. I've tried all manner of cache nodes, motionblur nodes, toggling settings, etc but still no camera motion blur. What might I be overlooking?

Following my above question: closer inspection of my imported USD camera revealed that it's open and close shutter times were both 0, indicating an instantaneous shutter. So, no manner of jiggling settings on Cache nodes or Motion Blur lops helped, but using an Edit Camera node to set open/close shutter times to nonzero values (-0.25 and 0.25 in my case) solved my issue and I can now see motion blur.

Leaving this here in the event it's helpful for anyone else.