carstenkolve Posted December 10, 2009 Share Posted December 10, 2009 (edited) Hi, I'm looking into obtaining even but randomish point distributions on my geometry (even as in even distances between the points). I'd like to paint a density map for where the points should bunch up and I don't want to be bound to uv space. Here an example of a grid with a density map: (pic A) A straight scatter gives me something like this: (pic B ) My current approach is to to generate multiple scatter densities, fuse them individually with a different radius to get an even looking distributions at differerent densities and then blend them together based on the painted value - something like this: (pic C) Which works alrightish, but as the blending is based on randomness I get points overlapping in the blending areas. A final fuse helps to get rid of the worst offenders, but it's still not very pretty... I think the next thing to try would be a particle repulsion based approach... Anyone here would like to share their approach to the problem (I guess it must come up quite often for feathers and the likes). Cheers! Carsten Ps: there is a rough hip attached to demonstrate the approach pointDistribution_v001_001_ck.hip Edited December 10, 2009 by carstenkolve Quote Link to comment Share on other sites More sharing options...
Ratman Posted December 10, 2009 Share Posted December 10, 2009 Are you trying to do this over 3d geometry not a 2d plane? I'm looking at your file and for what I think you're doing might be overcomplicated from what I gathered there. Would changing the geometry to black and painting red and scattering based on color be what you're looking for? Edit. ack, I think I see what you're saying now pointDistribution_v001_002_ck.hip Quote Link to comment Share on other sites More sharing options...
petz Posted December 10, 2009 Share Posted December 10, 2009 not sure if this is what you are looking for but attached is the file. hth. petz pointDistribution_v001_003.hip Quote Link to comment Share on other sites More sharing options...
carstenkolve Posted December 10, 2009 Author Share Posted December 10, 2009 Heya, Thanks for this - while your doesn't quite give me what I'm looking for, it's certainly very interesting (+ I get to see how to use all those pointcloud vex nodes I've never touched). It produces a nicely distributed set of points of roughly uniform density throughout - but in addition I'd like the points to bunch up more in areas of higher densities. I've got to see if I can adjust the distance between the points based on the density map... Just found some images that explain what I'm after better "poisson disk sampling" - http://www.devmag.org.za/articles/55-POISSON-DISK-SAMPLING/#top3 luckily there is also lots of pseudocode on the same page, so I might have a look at implementing it in houdini... Cheers! not sure if this is what you are looking for but attached is the file. hth. petz Quote Link to comment Share on other sites More sharing options...
petz Posted December 11, 2009 Share Posted December 11, 2009 maybe something like this? petz pointDistribution_v001_004.hip Quote Link to comment Share on other sites More sharing options...
carstenkolve Posted December 11, 2009 Author Share Posted December 11, 2009 nice one! that's a pretty good distribution - only need to cull the P that go outside the geo and I'm golden. cheers! .carsten Quote Link to comment Share on other sites More sharing options...
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