Hello,

What I'm looking for is similar to Nuke's O-flow tool (where a 2d grid of motion vectors are generated for an image sequence, based on image information).

I wonder if similar could be possible using existing Houdini tools (microsolvers?) for volumes? Say, I have a sequence of 3d volumes (scalar/density), and I'd like to generate a motion vector volume for them, by analyzing the difference between the volume on the current and the next frame.

I hope I'm making sense here

thanks
iosman

I think this is the node you're looking for, but I'm not sure if it exists as a microsolver. If you need it in a solver, it can be put into a sop solver.

https://www.sidefx.com/docs/houdini/nodes/sop/volumeopticalflow.html [www.sidefx.com]

You don't need a microsolver for this but if you need it, you can just invoke Volume Optical Flow from a SOP Solver DOP inside a DOP network.