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In article <397### [at] peak edu ee>, Margus Ramst
<mar### [at] peak edu ee> wrote:
> Strange, it sometimes happens without running ipf previously
> (although that seems to be a sure-fire way). Haven't found the
> connection yet.
It still sounds like an uninitialized variable or a dangling pointer.
> I see. Actually, I think this is sufficient in most cases, especially
> with liquids.
Inter-particle collisions would probably just interfere with liquid-like
behavior.
> As for the "solid" particles - I don't think inter-particle collision
> and deflection would be at all expensive for spherical particles, and
> prohibitively expensive for most other shapes.
Actually, the only way I can think of doing it would also work for
arbitrary shaped objects(like meshes), but would be computationally
expensive for all of them. I suppose the cheapest one would be a
triangle, followed by triangle pairs, other simple, non-solid shapes,
and boxes. Spheres would definitely not be the cheapest.
I definitely need to learn more about rigid body dynamics before I try
this.
> What physical properties would be needed? Collision is easy,
> deflection and impact energy absorption too, friction I'm not so sure
> about... What else?
Impact energy absorption already exists, as elasticity. Friction
coefficient, shatter speed, geometry, etc. Internally, center of
gravity, angular velocity, a bounding box...
> BTW, I found an interesting page discussing sorting algorithms for
> particle systems (specifically kd-trees and Barnes-Hut trees). I saw
> no actual code, but pretty informative nevertheless. The URL is:
> http://physics.gmu.edu/~large/lr_forces/lr_general.html
Thanks, I will take a look...
--
Christopher James Huff - Personal e-mail: chr### [at] mac com
TAG(Technical Assistance Group) e-mail: chr### [at] tag povray org
Personal Web page: http://homepage.mac.com/chrishuff/
TAG Web page: http://tag.povray.org/
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