Motion vector AOV in Karma

   12355   24   7
User Avatar
Member
7 posts
Joined: 2月 2016
Offline
Is it possible to do in karma. Does anyone still use it?
User Avatar
Member
88 posts
Joined: 2月 2021
Offline


This seems to do the thing.
Edited by TangheStudent - 2022年3月25日 19:38:41

Attachments:
houdini_Rh5eGENm98.png (10.5 KB)

User Avatar
Member
651 posts
Joined: 11月 2013
Offline
TangheStudent
Image Not Found


This seems to do the thing.

Hi,
I tested ,but it has not effect because there is no velocities primvar if animating by transform lop.
User Avatar
Member
88 posts
Joined: 2月 2021
Offline
what you need to do then is add the v atribute with a trail sop and rename it to velocities.
It could be that you need to promote the attribute to a primitive aswel wich might paint ver primitive instead of point.
But i haven`t tested out if it works with points.
User Avatar
Member
123 posts
Joined: 9月 2018
Offline
Just to note this. As far as I can see, the velocities described in this thread are only taking into account the velocity on the geometry not the geometry relative to the camera.
But I also can’t give any explanation on how to create a proper motion vector AOV like in mantra.
Edited by No_ha - 2022年5月29日 02:42:35
User Avatar
Member
88 posts
Joined: 8月 2019
Offline
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity
User Avatar
Member
651 posts
Joined: 11月 2013
Offline
arx_anima
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity

Hi,
I tried ray:motionvector and ray:velocity, but can't get the result.
Could you give any tip?

Thanks!

Attachments:
mvector.png (169.4 KB)

User Avatar
スタッフ
2641 posts
Joined: 7月 2005
Offline
I think you'll find that this will have a much improved workflow in the next major version of Houdini.
User Avatar
Member
2 posts
Joined: 1月 2019
Offline
What's the difference between motion vector and velocity. Is it with respect to camera? I'm getting data rendered in motionvector but not in velocity
arx_anima
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity
User Avatar
Member
8042 posts
Joined: 9月 2011
Offline
agastyafx
What's the difference between motion vector and velocity. Is it with respect to camera? I'm getting data rendered in motionvector but not in velocity
arx_anima
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity

motionvector is a screenspace vector, useful for post processing applications of motion blur. I'm not sure what ray:velocity is, but it's probably in world space.
User Avatar
Member
75 posts
Joined: 12月 2017
Offline
jerry7
arx_anima
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity

Hi,
I tried ray:motionvector and ray:velocity, but can't get the result.
Could you give any tip?

Thanks!





It's seems to be a Houdini19.5 things.

Attachments:
motion_V.jpg (32.7 KB)

User Avatar
Member
1 posts
Joined: 2月 2023
Offline
it doesnt work in xpu
User Avatar
Member
44 posts
Joined: 3月 2023
Offline
you can do a pass with cpu where you don't render anything except the aov.
User Avatar
Member
19 posts
Joined: 5月 2021
Offline
arx_anima
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity

Hey there,
I tried checking both the motionvector and velocity in the karma render node, however I still get a blank output. Am I missing something?

Thanks!

Attachments:
rendervars.png (34.6 KB)
noop.png (49.6 KB)

Pranesh Arry
3D Generalist at North Studio
User Avatar
Member
3 posts
Joined: 7月 2021
Offline
For motion vector to appear in renders do not forget to setup "Motion Blur" in Karma Render Properties [www.sidefx.com] and cache [www.sidefx.com] your animation.
Edited by 0x384c0 - 2023年6月21日 08:46:15
User Avatar
Member
4 posts
Joined: 9月 2012
Offline
pranesh arry
arx_anima
the karma node or the karma standart rendervars node has motion vectors and velocity aov as default to check.
We used them already in production and they work fine, they do not use primvars but a ray level check
ray:motionvector
ray:velocity

Hey there,
I tried checking both the motionvector and velocity in the karma render node, however I still get a blank output. Am I missing something?

Thanks!
Image Not Found

Image Not Found

Have you managed to make it work? I've been stuck trying to output AOV motion vectors with no sucess
User Avatar
スタッフ
413 posts
Joined: 2月 2008
Offline
On the Karma Render Settings LOP node, if you turn off Rendering > Camera Effects > Disable Image Blur do you get the expected motion blur?
Are you rendering with XPU or CPU? Only CPU has motion vectors supported at the moment.

Here's a hipfile that shows it working.

Attachments:
MotionVectors.hip (531.7 KB)

User Avatar
Member
2 posts
Joined: 5月 2015
Offline
I think I have a related problem. When I turn on motion blur (velocity) in Karma render settings and turn on Disable Image Blur, when rendered the geometry shifts towards motion blur direction. When Disable Image Blur is turned on it renders as expected. If I do not turn on motion blur, I do not get any velocity or motion vector AOVs, they come out blank. Tried it both on CPU and GPU and in both cases its the same. I'm on 20.5.278 right now.
User Avatar
Member
142 posts
Joined: 11月 2017
Offline
Simply doesn't work in 20. Nightmare. Or 20 settings need to be in a certain way that even a lottery win is more likely. Both CPU and XPU don't tint any pixel in the Motion Vector path.
User Avatar
Member
142 posts
Joined: 11月 2017
Offline
20.5 the same. No shading except from black pixels in the motion vectors aov. 20.5.332

Normal map, depth map, all show up nicely. MV doesn't.

What are the setting which need to be enabled/disabled to get the correct aov?
  • Quick Links