Collision detection: Difference between revisions

Revision as of 03:35, 28 November 2024

Revision as of 01:54, 4 December 2024

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</ref> The same approach works for pair wise collision and self-collisions.

=== Exploiting temporal coherence ===

During the broad-phase, when the objects in the world move or deform, the data-structures used to cull collisions have to be updated. In cases where the changes between two frames or time-steps are small and the objects can be approximated well with an [[axis-aligned bounding box]]es, the [[sweep and prune]] algorithm<ref name=":0" /> can be a suitable approach.

Several key observation make the implementation efficient: Two bounding-boxes intersect [[If and only if|if, and only if]], there is overlap along all three axes; overlap can be determined, for each axis separately, by sorting the intervals for all the boxes; and lastly, between two frames updates are typically small (making sorting algorithms optimized for almost-sorted lists suitable for this application). The algorithm keeps track of currently intersecting boxes, and as objects moves, re-sorting the intervals helps keep track of the status.<ref>{{Cite book |last=Ericson |first=Christer |url=https://realtimecollisiondetection.net/books/rtcd/ |title=Real-time collision detection |date= 22 December 2004|publisher=Elsevier |isbn=978-1-55860-732-3 |edition=Nachdr. |series=Morgan Kaufmann series in interactive 3D technology |___location=Amsterdam Heidelberg |pages=329–338}}</ref>