Often, for common point lookup tasks, for the sake of ease, when I want to look up point info I just use the nearpoint() function or just a simple pcopen() followed by pcfilter(). I've also used pciterate and the other related functions for occasional purposes.

But there are a lot of point cloud functions I never use, and because they exist, they must be useful. Ideally I'd want to find out which ones will make my point lookups as fast as possible.

Are there any pro-level tutorials that go over them with examples anywhere?

Cheers,

Jon

Only thing that you need to know about Houdini it's this
Than just combine
https://www.youtube.com/watch?v=dq5B3TeFeL8 [www.youtube.com]

srletak76
Only thing that you need to know about Houdini it's this
Than just combine
https://www.youtube.com/watch?v=dq5B3TeFeL8 [www.youtube.com]

Sorry but I didn't see anything about the point cloud specific VEX function that I mentioned. I'm not a beginner by any stretch of that word.

I find the pointcloud functions that return arrays to be the most useful. The while pcopen/iterate shenanigans are from another time. I'm not sure if there's any performance implications between them.

The grid based pgfind uses a different algorithm that may or may not be faster in some circumstances, it's worth checking out.

I think Jon means functions like pcopenlod() and pcsampleleaf() which can speed up point cloud queries
https://www.sidefx.com/docs/houdini/vex/functions/pcopenlod.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/pcsampleleaf.html [www.sidefx.com]

I have seen them being used in the shading context, however never used them myself

tamte
I think Jon means functions like pcopenlod() and pcsampleleaf() which can speed up point cloud queries
https://www.sidefx.com/docs/houdini/vex/functions/pcopenlod.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/pcsampleleaf.html [www.sidefx.com]

I have seen them being used in the shading context, however never used them myself

Neat, never used those before. Sounds like something a photon shader would use such as the gi light.

jsmack
I find the pointcloud functions that return arrays to be the most useful. The while pcopen/iterate shenanigans are from another time. I'm not sure if there's any performance implications between them.

Last time I checked there was a performance difference favoring the old pcopen.

tamte
I think Jon means functions like pcopenlod() and pcsampleleaf() which can speed up point cloud queries
https://www.sidefx.com/docs/houdini/vex/functions/pcopenlod.html [www.sidefx.com]
https://www.sidefx.com/docs/houdini/vex/functions/pcsampleleaf.html [www.sidefx.com]

I have seen them being used in the shading context, however never used them myself

Yes, exactly… Jeff Wagner talks about pgfind in his VEX masterclass and touches on point clouds a little bit, but sometimes it's hard to creatively imagine novel uses for these. I'm guessing a lot of them were added with specific use cases in mind.

Some sort of example page with snippets for each would be fun to create some day. (Matt Estela? )

jpparkeramnh
I'm guessing a lot of them were added with specific use cases in min

this may be the intended use case
$HFS/houdini/vex/Light/sampler_pclight.vfl

jpparkeramnh
Jeff Wagner talks about pgfind in his VEX masterclass and touches on point clouds a little bit, but sometimes it's hard to creatively imagine novel uses for these.

Hi Jon -

This may or may not be helpful but in the vellum solver (for the grains) there's a VOP called “get_neighbors” that uses both pcfind and pcfind_radius (switched by the “uniform_radius” parameter), and there's a bit commented out on pgfind (which IIRC is for accessing points that are spatially partitioned in to blocks the way a VDB might, could be wrong tho) - all of that could be a bit of a clue as to what the finer distinctions between them are.

-T

Peace @jpparkeramnh

I just wanted to say that you can use color value to
manipulate everything in Houdini. But calm you will eventually grasp
Have a nice day.

Thanks all, appreciate the reply. There's no free lunch here… and no substitute for a lack of free time to play around with the functions myself.