Etienne Vouga

I have a sequence of .obj files, and a list of times in a text file. I would like to turn each mesh into a keyframe at the specified time, i.e., all of the point positions in the i-th mesh are where those points should be at the i-th time in the text file.

What's the best way to do this?

I see that I can create a channel for each point's XYZ coordinates, using the Geometry node inside a CHOP. But then how do I populate the channels with data imported from the mesh sequence?

I have some complex, highly concave geometry that consist of a thin volume enclosed by a pair of surfaces (loaded from two .obj files; these surfaces are very close together but do not intersect). I want to render the cross-section of this volume, i.e. intersect the volume with a plane.

The way I'm trying to do this now is by taking the two .obj meshes, inverting the normals on one of them, merging them together, and then using Cookie intersect on this object and a plane (created using an isosurface using the equation aX + bY + cZ + d = 0).

It… kind of works. But Cookie seems to be very buggy/non-robust and so I get artifact triangles from the plane that aren't actually inside the volume, pieces of the “cap” in the interstitial space that are missing, etc. Playing around with the “3D tolerance” helps a bit but doesn't actually fix the problem completely (in fact setting it too small is disastrous). Jitter doesn't seem to help at all.

Is there a more robust way of doing boolean operations, for the special case where I just need the cross-section with a plane?

I have simulation output that I would like to render. The geometry is stored in a sequence of .obj files, and Houdini loads these very easily using the File node.

Now each .obj has a corresponding .txt file containing extra information that I want to use for rendering: a list of vertex indices and brightness values, e.g.

0 .1
1 .2
2 .1
3 .5
4 .6

etc.

What is the easiest way to load this data into Houdini?