Here's what I want to do:

I have an animated and deforming mesh and I want to apply (animated) Displacement onto it. The mesh was created inside Houdini out of a liquid simulation done in Realflow.

I just imported particles from Realflow and used the mesher inside Houdini. The problem is, the newly created mesh doesn't have any UVs on it.

If I project a static UV Map, this will not work with the Displacement and look strange, as the Displacement will be too different from underlying liquid motion. I need to find a way to animate the UVs so the Displacement will move with the geometry.

So I could measure the average point velocity of the mesh and probably animate the projected UVs accordingly. I was wondering if this was a good idea or if there was maybe a better and easier way (or more complex but more stable) to be doing so.

Any help is very much appreciated!!

Can you use a rest position sop?
Jim

Hi,

You could try and have UVs on points prior to meshing. If the point count not changing, then no problems at all, just create UVs on first frame. If it is, you have to setup something like assigning UVs with the emitter. After that transfer UVs to your mesh.

But of course this technique may produce weird results as the particles mix within fluid volume.

Maybe you can also find this paper useful: http://gamma.cs.unc.edu/TexturingFluids/ [gamma.cs.unc.edu]

Hi,

Thank you for your answers so far.

the Problem is emission for the particles doesn't take place inside Houdini (Realflow), particle counts are changing and as is the topology and poly counts.

We have 2 different node in the Houdini to project UV on the mesh.
1. UVTexture SOP
2. UV Project SOP

(Of course we have another nodes to do that like UV Unwrap SOP)

UVTexture SOP is depended to mesh topology and point's count
But UV Project SOP is independed .

Maybe you can solve your problem with UV Project SOP :?

the Problem is emission for the particles doesn't take place inside Houdini (Realflow), particle counts are changing and as is the topology and poly counts.

Yes, I got that. What I meant is you could probably assign UVs within your emitter area (volume) in Houdini and make them particles inherit it across their ways.