hi, it'd be cool if we also had a good kdtree implementation for spatial stuff too :) For cases when we had say 1000 objects or so.
note, the wikipedia entry has a basic implementation in python http://en.wikipedia.org/wiki/Kd-tree There's also some quadtree python code lying around if you needed it(see cookbook). However, maybe even a simple grid will be better for you. cu, On Fri, Oct 10, 2008 at 2:46 AM, Peter Gebauer <[EMAIL PROTECTED]> wrote: > Hello René. > > The thing is, in a large world spanning 16000x10000 pixels that will be a > huge mask. Even if I reduce the resolution of the mask alone it will be > either top inprecise or still too large. > > I don't want to write for OpenGL alone even though the plan is to use OpenGL > as test output. My plan is to build a large world of 3 or 4-sided > convex polygons that could be used to detect colliding with large shapes in > that world. > > The best way to do this is probably to expose some of Zhang Fan's physics > code, much of the math involved is already there, it just lacks > non-rectangular shapes and a nice Python API to access it. > > /Peter > > On 2008-10-09 (Thu) 11:41, René Dudfield wrote: >> hi, >> >> Note, that you can find contact normals with the mask module. See mask >> example. >> >> For some types of games, per pixel collision detection is fast enough. >> It uses rect bounding boxes as a first pass, so mostly it's not much >> slower than rect collision detection. Assuming you are working in 2d, >> and you cache the mask(not regenerating it every frame) that is. >> However the mask.from_surface routine is fairly fast, it could do with >> some more optimization. >> >> For opengl, it'd be interesting to do it in a shader too... since then >> you could just reuse your drawing routines to draw your >> objects(sprites) into a buffer (each with a different color), then use >> a shader to find all of the contact normals. That way your collision >> could be pixel perfect, even with different methods of >> drawing(cartoon, glow, and other shaders) where the polygon >> representation is not correct. >> >> >> cheers, >> >> >> >> >> On Wed, Oct 8, 2008 at 9:46 PM, Greg Ewing <[EMAIL PROTECTED]> wrote: >> > Nirav Patel wrote: >> > >> >> If the polygons are Surfaces or can be turned into Surfaces, they can >> >> be turned into Masks to do pixel collision. >> >> >> >> On Tue, Oct 7, 2008 at 11:21 AM, Peter Gebauer >> >> <[EMAIL PROTECTED]> wrote: >> >> >> >> > Yep, but as I said, I need to find colliding polygons, not pixels. >> > >> > Pixel collision isn't suitable for all purposes, >> > e.g. if you need to find contact normals for >> > physics calculations. >> > >> >
