Line 65 to 76 are not really drawing the mesh (in a Processing draw way), but rather creating the mesh. If the points do not change, it would be more efficient to create the mesh once instead of 60 times per second. In other words seperate the creation from the drawing of the mesh. For example by putting that code in a createMesh() function that you call when you want to build the mesh. Doing the creation once (only when needed) and then drawing continuously, will improve the speed of your sketch significantly. If necessary you could put a if (mesh == null) check in your code or just make sure the mesh is never drawn before it's created.

On a side note you could use java generics with your arraylists. While you have only posted a partial, non-runnable example, I believe something like this would work in your code:

1. // something like this...
   
2. ArrayList meshPartList = new ArrayList();
3. for (int i = 0; i < meshPartList.size(); i++) {
4.   Particle newPart = (Particle) meshPartList.get(i);
5.   brush.drawAtAbsolutePos(new Vec3D(newPart.pos.x, newPart.pos.y, newPart.pos.z), density);
6. }
7. 
   
8. // could be rewritten like this...
   
9. ArrayList <Particle> meshPartList = new ArrayList <Particle> ();
10. for (Particle p : meshPartList) {
11.   brush.drawAtAbsolutePos(p.pos, density);
12. }

Hi Amnon,