Hi,
I would really appreciate any help and ideas from all you Java gods with regards to the following 2D problem:
- How do I detect AND recover from a collision between arbitrary polygons (convex or concave with more than 3 vertices) in 2D rotating and moving directionally at different speeds?
I was thinking of checking each line segment generated from each BEFORE MOVING vertex of polygon A to the AFTER MOVING vertex, against all the edges of the polygon B. The process is then repeated for polygon B “moving” in the opposite direction. Very brute-force I know, but at least it solves the speed problem with collision detection.
I’ve linked a pic to illustrate: http://www.imagedump.com/index.cgi?pick=get&tp=49876&poll_id=0&a mp;warned=y
In the picture, the red line segments generated from the movement are checked against the blue edges of the green polygon. The red circles represent the point of intersections.
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To detect collision during DIRECTION MOVEMENT at arbitrary speeds, i find the before and after coordinates and use the above algorithm. To correct the movement, I find the point of intersection with the least displacement from the original vertex and translate the polygon there instead.
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To detect collision during ROTATION at arbitrary speeds, i would use the exact same process, with the exception that line segments are now rotation arcs.
My big and ugly problem is that I can’t find a neat and (somewhat) efficient algorithm to compute the angle I must “un-rotate” to get the correct displacement. Since I’m hardly a mathematician, the algorithm I have, in a word, sucks.
Can anyone help with the algorithm? Is this even a good way to get around the problem? :-/
Thanks.