Cool! I always wanted to add the ray intersect test to make this thing more robust, but have long since run out of energy...
Ciaran On Wed, May 8, 2013 at 1:14 AM, Eric Thivierge <ethivie...@hybride.com>wrote: > Thanks guys, > > Ciaran, your addon actually works exceptionally well in my case. The > slider for the "Override_test_distance" gets rid of the errant areas very > very well. Not to mention generating this particle cloud is super fast now. > You've saved me some late night work today. :) > > I did try to roll my own but was still getting the unwanted areas. The > tips on how to build it are appreciated as it may help in future cases. > > Cheers, > > > Eric Thivierge > =============== > Character TD / RnD > Hybride Technologies > > > On 07/05/2013 7:23 PM, Ciaran Moloney wrote: > > IIRC implementing the ray intersect technique is problematic in ICE, since > the raycast node only returns the first intersection. You'd have to > manually shoot subsequent rays after every hit. > > > > On Wed, May 8, 2013 at 12:06 AM, Raffaele Fragapane < > raffsxsil...@googlemail.com> wrote: > >> You could write/wire the test yourself. >> Point inside hull is fairly trivial outside of fringe cases, shoot a ray >> in any direction, if it intersects an odd number of times, it's outside, >> even, it's inside. >> You might want multiple rays and take the median of the result, or work >> conservatively and flag it even if just one tests true. >> >> You can further refine this with a force field approach, run a distance >> from hull (closest location on geo), and if the point is close enough to a >> location with a normal facing away from its distance vector remove it, and >> remove anything within a certain threshold (very close) indiscriminately. >> >> Testing against denser geometry also helps, even if it's more expensive, >> sparse and variedly populated topology tends to introduce more room for >> error. >> Lastly, a triangulated mesh, especially if you have a certain degree of >> dis-planarity in your geo on large enough areas, will also improve things >> in my experience. >> >> >> >> On Wed, May 8, 2013 at 4:54 AM, Eric Thivierge <ethivie...@hybride.com>wrote: >> >>> Anyone notice how many times this just doesn't work correctly? Even >>> toggling the Closed volume inside often doesn't give the correct results as >>> well... >>> >>> I have a voxel setup with particles and testing inside a geometry to >>> keep the ones that are within, works, however there are many points still >>> outside the geo that remain and aren't deleted. The ones left outside >>> changes each frame as well. >>> >>> Anyone have any sure fire methods / workarounds that don't involve >>> having helper nulls to delete the remaining ones outside? >>> >>> -- >>> Eric Thivierge >>> =============== >>> Character TD / RnD >>> Hybride Technologies >>> >>> >>> >> >> >> -- >> Our users will know fear and cower before our software! Ship it! Ship it >> and let them flee like the dogs they are! >> > > >
