[Bf-committers] Particle surface reconstruction issues (Farsthary)

[Raul Fernandez Hernandez]

Hi all :)

 Check some new videos at http://farsthary.wordpress.com

  The fluid is performing well so far, I have being able to push it to the
current particle limit (100k particle) without much stress (though at
those numbers is far from realtime ;) ) and Stephen is working hard in
the stiffness code.

  Currently I wanted to handle the surface reconstruction code but i'm
facing some issues:

  Metaballs could be used as instanced particles but only for relativelly
small number of particles but metaballs always return a blobby fluid.
  For Eulerian fluids (Grid based) is relaively straigthfoward to
implement a meshing algorithm using the already discretized domain, for
particles based simulations there's a hundred of papers explaining the
particle dynamics but very few actually tackle the surface
reconstruction and many approaches fall in the cathegory of discretizing
a domain with grids.

  But that's exactly what I want to avoid: using a grid domain for meshing
limit the principal advantage of the particle fluid. So the remaining
solution is using an octree/kd tree based scene domain, that although is
still a discretization of the domain is transparent to the user and
there's no need to define a domain at all, and here is where I get
stuck.

  I was reviewing the metaball's code since it performs the way I want
(correct me if I'm wrong), it uses an octree to store the metaelements
wich define a mathematical density function based on the distance to
each metaelement ,and for polygonalization it march trough the cubes,
but only the cubes defined in the metaballs.
 What SPH particles need is similar but with a sligthly difference: the
density function is not a mathematical returned value that depends only
on distance to the mball centre, the density function should be returned
from querying the ParticleSystem Kdtree.

  Who was the developer of Metaballs?
  Could someone suggest another approach?

  Also why metabalss don't support material blending?

                                 Thanks in advance           Farsthary