Hi all,
I am importing a lot of 3d models into a geometry node and wanna run some simulation on it. But there are too many vertices in some of the obj files. Is there a way to reduce the polygon count(which is like the opposite of subdivide)?

You can use the PolyReduce SOP:
http://www.sidefx.com/docs/houdini13.0/nodes/sop/polyreduce [sidefx.com]

But if you want to reverse a model subdivided using Catmull Clark subdivision, and get the original model back, there is no built-in SOP for that. Here is a paper if anyone wants to implement it for Houdini:

http://wscg.zcu.cz/wscg2006/Papers_2006/Full/B89-full.pdf [wscg.zcu.cz]

Thank you so much, Polyreduce is a Cool node That should definitely save me a lot of time

http://forums.odforce.net/topic/10181-de-subdivide/?p=73097 [forums.odforce.net]

pusat
You can use the PolyReduce SOP

There is also a Remesh SOP these days, for a bit different results.

SYmek
http://forums.odforce.net/topic/10181-de-subdivide/?p=73097 [forums.odforce.net]

This doesn't work on a subdivided box and other models I have tried. It might be missing certain cases like points shared by 3 edges.

eetu

pusat
You can use the PolyReduce SOP

There is also a Remesh SOP these days, for a bit different results.

That's a good SOP. I wish SESI implemented a CVT based Remesh SOP though that produces more equilateral triangles. I made one myself but without a Voronoi Split SOP that doesn't physically separate polygons, the fusing messes up the surface mid-process. A simple toggle parameter for that would be greatly appreciated