Using a point cloud to deform a mesh, help needed!

[claudevervoort]

Hi,

I'd like to experiment using a point cloud simulation to drive the deformation of a mesh. So to start playing with the idea, I did a crude setup:
- a sphere polymesh (the sphere to be deformed)
- a point cloud emitting points from the sphere with a gravity force (that will drive the deformation)

So the idea is that, at the beginning of the sim, an ICE tree on the sphere will find for each point the closest point in the point cloud and remember the ID of the associated point.

Then, on each step, each point in the sphere will be updated to match the position of its peer point in the cloud. As a result, the sphere should deform as the point cloud.

Well it works fine for the first few frames, then (for no obvious reason to me) it degrades. Points in the mesh start to be bounded with a single point in the point cloud, until the all points of the sphere collapse in one point.

Since i've been looking at that for quite some time, I thought I'd ask, hopefully someone can shed some light on this.

I've attached the scene (2012 SP1) in case someone wants to give a try,

Thanks!

Claude

[Pooby]

YOu arent running it as a sim. so its evaluating every frame,

[claudevervoort]

Thanks a ton, that did it!!!

(Glad I asked, I somehow did not see the simulation step missing from there and thought the animation step was doing the same thing).

Claude

[Chris_TC]

I think your If statement does not actually do anything. Can you visualize it and see if it's ever true?
And for faster performance I think it would be advantageous to do the point assignment in a separate ICE tree that's not in the simulation stack, so that it evaluates only once.

[Robert_XSI]

Lagoa would be ideal for this. i just do not know how to connect a pointcloud to a mesh. any ideas?

[claudevervoort]

Chris: thanks for chiming in I actually started putting the 1st branch in the modelling section, but that was getting evaluated each time. In addition I need to take a capture of point positions of a simulation, which I believe generate points at frame 1. But i'll play a bit more (btw the if evaluates to false until a mesh point is bounded to a point cloud point).

Robert: that's exactly what I am after! As you see here, I bind a mesh to a point cloud. I started with a proof of concept using a simple mesh and a simple sim, but my real goal is to try with Lagoa Jello...

I hope to be able to get back to it soon, and i'll post around if/when I make any progress.

Claude