magneto Posted December 22, 2015 Share Posted December 22, 2015 Hi, I am using an SDF to move my points on the surface of my geometry but it doesn't work. Is it because my SDF volume has to encapsulate all the points? I thought SDF can still return correct distance and gradient outside its boundaries. Am I wrong? Thanks gradient.hip Quote Link to comment Share on other sites More sharing options...
symek Posted December 22, 2015 Share Posted December 22, 2015 Why are you conveting SDF back to polygons (twise)? If you turn off three nodes after vdbfrompolygons1 it seems all works as expected (points colapse onto mesh)... 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted December 22, 2015 Author Share Posted December 22, 2015 Thanks Symek, I thought the initial mesh wasn't correct, holes etc. Quote Link to comment Share on other sites More sharing options...
fathom Posted December 22, 2015 Share Posted December 22, 2015 not that it necessarily pertains here, but one thing to be aware about with sdf's and vdbs -- since vdbs are sparse, you can't always rely on them to provide good distance info as you get farther away from your surface (since you're likely to end up outside the active area). 1 Quote Link to comment Share on other sites More sharing options...
magneto Posted December 23, 2015 Author Share Posted December 23, 2015 Ok I Just checked but it doesn't work completely: As you can see some points are outside the duck. Is this normal? Quote Link to comment Share on other sites More sharing options...
Hamp Posted December 23, 2015 Share Posted December 23, 2015 Hmm, are you growing your exterior band sufficiently? Quote Link to comment Share on other sites More sharing options...
magneto Posted December 24, 2015 Author Share Posted December 24, 2015 Hmm, are you growing your exterior band sufficiently? No. Similar issues happen with IsoOffset SDFs though. Also if I extend the volume to encapsulate the points, the volume could become a lot bigger, heavier or crude. I thought the point of SDFs was fast checking of collisions but with these issues, I don't know how you could use them efficiently. Quote Link to comment Share on other sites More sharing options...
fathom Posted December 24, 2015 Share Posted December 24, 2015 maybe a raysop would be more appropriate then -- nearest point. 1 Quote Link to comment Share on other sites More sharing options...
Hamp Posted December 24, 2015 Share Posted December 24, 2015 Would also love to find out why this happens. My suggestion came from a attractor setup I tried that worked with isooffset but not with vdb unless I expanded exterior band to encapsulate everything. 1 Quote Link to comment Share on other sites More sharing options...
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