Wednesday, July 02, 2008

Real Triangles, well infinate planes anyway...

The first big steps to removing the need to subdivide meshes has been taken. The biggest chunk of the required infrastructure is in place and working. The triangles however are approximated as infinite planes instead. But due to the fact that I use the particle boundary code there should not be to many issues to iron out as most of the code has been used a quite a bit.

I make one quite big assumption. I approximate all properties across the face of a triangle as a linear combination of the vertex values. This means that velocity of the face is not accurate for large polygons that are rotating, but this can be solved simply with subdivision for these perhaps quite rare cases. Another consideration is that the force of the fluid is transfered to rigid bodies in a similar fashion for rigid body dynamics, and this could also lead to inaccuracies and perhaps instability.

The code is not in the best state, and there is still quite a bit of try and comment out code as well as out right hacks in there. The is already one regression. The plugin does not preserve state of object that are created after the physics plugin for example.

In order to catch regressions early, I was thinking of releasing regular snapshots that are simply totaly untested. If folks would like this it would mean that regressions would be picked up sooner rather than later. Otherwise the whole debug cycle gets a little slow. Let me know what you think.

So the next *proper* beta release (0.7) I will hopefully have the following fetures.
  • Full polygon boundaries for moving and stationary objects.
  • Basic Rigid body dynamics.
  • Animating parameters.
I have also noticed some serious performance issues. Its just much slower than it should be. This will perhaps not get looked at in the next release.


Anonymous said...

Nice to see you're back on track with this.

Anything which helps speed up the process must be good so I would be in favour of trying out untested versions to help find regressions.


Anonymous said...

Hi Bob,

regarding "release soon - release often" to shorten cycles via snapshots:

Yes - please do so!