I have a motion capture footage in a point cloud format and I need to use it for some simulations. The problem is that the particles are not moving from one position to the other but just appearing for one frame and there are different points on the next frame so there is no velocity or anything other then just plain positions which is not that useful for simulations.
I need a constant group of particles to move with the mocap.
I'm thinking about converting the point cloud to VDB and then make a set of points that follow that volume. I managed to fill the volume with points but I cant figure out how to make them follow the volume?
How should I do this? Also maybe it's not the best solution so I'm open to other ideas.
Thanks in advance for any help.
Particles follow volume
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- zeke.adam
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- AndyW
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- circusmonkey
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That does not sound ideal ….
Off the top of my head > I would just add a trail sop to create all my points over the entire animation range, then as your points turn on / off per frame, you could use that as a boolean trigger to emit particles from your trail ie > active or not. Create a direction vel vector and emit from there with pops.
You could refine further by creating lines from emitted pops / trail sop , based on a attribute , then create a flow direction vector and emit from there. Certainly a few options , fancy sharing a clip of your pointcloud ?.
Rob
Off the top of my head > I would just add a trail sop to create all my points over the entire animation range, then as your points turn on / off per frame, you could use that as a boolean trigger to emit particles from your trail ie > active or not. Create a direction vel vector and emit from there with pops.
You could refine further by creating lines from emitted pops / trail sop , based on a attribute , then create a flow direction vector and emit from there. Certainly a few options , fancy sharing a clip of your pointcloud ?.
Rob
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- zeke.adam
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Of course, here is a sample:
https://drive.google.com/open?id=0B5BNtY3ovu44M2huTEw5X3JlZU0 [drive.google.com]
I couldn't get the mentioned methods to work.
I'm looking at tutorials and forums for days and tried many things but can't get my head around how to solve this.
Thanks for the help!
https://drive.google.com/open?id=0B5BNtY3ovu44M2huTEw5X3JlZU0 [drive.google.com]
I couldn't get the mentioned methods to work.
I'm looking at tutorials and forums for days and tried many things but can't get my head around how to solve this.
Thanks for the help!
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- circusmonkey
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Unfortunately in the real world there is not a tutorial for everything, you just have to get digging and start exploring ideas and break your problem down into bite sized chunks. Fortunately Houdini is the perfect tool for this. 
Addictive as your problem is I have to get back to work, but here's 10mins of digging around with the problem to get a base start point. ie using the trail sop , adding a attribute that's got a value on each start frame. So we can see whats happening to all the points over the frame range. so we can see a slice of whats happening .
Rob
Addictive as your problem is I have to get back to work, but here's 10mins of digging around with the problem to get a base start point. ie using the trail sop , adding a attribute that's got a value on each start frame. So we can see whats happening to all the points over the frame range. so we can see a slice of whats happening . Rob
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- Karl Richter
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- Karl Richter
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Well, I couldn't leave it at that. Here is a more optimized version with reseeding. The main issue with this method is that when disconnected areas of the point cloud appear and disappear, the tracking breaks down. This is not a perfect solution, but I think you could use it to generate a decent velocity field….
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- zeke.adam
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