Possible To Unify Varying Topology On A Filesop?

[frankvw]

Hi,

I have been provided a geo sequence as obj files, I need do some houdini things to the character to make him gooey and melting with metaballs. All fine so far, something that worked out fine on another character. Problems I am having are that the geo sequences for this critter have varying topolgy, points and primitive numbers varying slightly throughout the frame range.

And it is a legacy animation long since departed and only resurrected for this one piece, so I can't go back to the original animation that produced it.

Anyone know a way to unify geometry points, primitives, vertices across an animated geo sequence like this?

Thank you,

[3dbeing]

Are the total amount of points changing or just changing order?

If it's the total amount of points, that is quite strange, unless it was a bad model to begin with, obj's will remove any degenerate verts, which will change the count and order, still I would assum that would stay the same across the sequence.

If it's just the order, try sorting by vertex order with a sort sop.

Also try using the facet sop and remove inline points across the entire sequence.

Another possiblility is to polyReduce, and keep the lowest total number of points that exist in the sequence. then attribute transfer your uv's and other relavant attributes.

Othere than that I can't think of anything.

3db.

Edited March 5, 2007 by 3dbeing

[thekenny]

If your geometry is changing point count per frame on the fileSOP load then you are in a world of hurt. You would have to go back to the soure, which you said you can't so then you would have to try to find commonalities in the model per frame and reconstruct by hand or via procedural network if possible.

IF you have the same point/prim count per frame on the fileSOP load, just different point ordering then you could take on frame of geometry and use it as your "rest" and drop down the primMatchPointSOP.. i think it might be a protoinstall.. I can't remember.. anyway this sop will all you to match point number IF and ONLY IF the primitives are numbered the same way from geometry to geometry. This often happens on export of a .obj to maya and export of obj from maya to houdini. both packages have a different winding direction on the vertices.

IF you have different point and prim order per frame on the fileSOP load BUT the total count is consistent you could try your luck with the MatchtopologySOP and see if you can take a "rest" geometry and get the remaining to be conform to the rest's order. You may need to read the help on the SOP.. and see if you can get it to work. I have found it to work occasionally but sometimes it gets borked.

Otherwise.. you would have to go and try to rebuild your geometry from what you have... which is not pretty. You could do some of it in Houdini.. but really the power tools for this kind of work exist in surface fitting software used to create mesh from point clouds. They are usually used in automotive or industrial design where point cloud scans are used. I'm sure you could find something online.

Good luck

-k