[vtkusers] Realtime Particle Simulation

[Mrs. Mister]

hello,

i am doing realtime particle simulation in vtk. im using
vtkInterpolatedVelocityField and vtkRungeKutta45. in a loop
this computes the positions of the "streamline" as needed.
Now the dataset consists of ~800000 points and the most time
is spent by finding the cell for interpolating velocity.
now the problem is instationary and the mesh is not static.
when going instationary i run into heavy speed problems,
because i have to search in 2 datasets for each step.

i searched vtk classes and found vtk(Abstract)CellLocator,
which is an interface to an optimized search datastructure with
additional memory costs. i read several cxx files and tried
to figure out how to use this interface. i want to implement
an own search structure and/or use an existing one (vtkOBBTree).
i want to do several speed tests then.

i found vtkPointSet which has a member pointer to a
vtkPointLocator, but no cell locator.
maybe someone could point me to the right direction.
i know how to use the cellocator standalone, but i want to
use it with vtkRungeKutta45 and i dont know how i can
make vtkUnstructuredGrid to use a cellocator in FindCell, which
is used by vtkRungeKutta45.

on the other hand i want to try out some new sort of octree.
to compute the octree i need several geometric operations.
i have axis aligned bounding boxes in this octree (AABB) and
now i have to compute:
1. which cells are inside of the box
2. is the box inside of a cell
3. overlap cells and the box
... this is something like a collision, penetration check.
i hope vtk has such functions implemented. i read vtkOBBTree
source, but maybe someone has a usefull hint.
i want to save the octree to hd and reuse it.

so i think this is a bigger problem and hope that someone
is interested in it too! :-)

btw, im using vtk 5.4.2-r1 on gentoo linux and use
openscenegraph to visualize particles and geometrys.
technical hints, if using nightly build (because of features?)
is better, would be nice too.

bye
henry