collision detection michael fuller. overlap testing most common technique most error prone test if...
Post on 22-Dec-2015
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Intersection Testing
Predicts future collision before they happen
Multiple collision can occur in one time sample
Tests geometry of two swept objects
Intersection Limitations
Networked Games cannot reliably use this method.Needs perfect information to be accuratePacket loss can cause sync errors with timing
Assumes no Acceleration during stepsEngine would have to accommodate for this.
Geometry Testing
Very Tedious to Test Every Edge Instead use simplified geometry
Alex from Half-Life 2, Model, Hit Boxes, Physics Model
Simplified Geometry
Use Simplified models for Testing Not acceptable for all games
Physics Model Render Model
Minkowski Sum
Merge two shapes and create a new volume
Determine Overlap by testing if a single point is contained inside of the sum.
Bounding Volumes
Turn Complex objects into bounded areas for testing
Fast, but not reliable Great 1st test, but should be followed by
another test
More Bounding Boxes
Use of Multiple Bounding Boxes Chain of Bounding Boxes
G-Man, Dog & Alex from Half-Life 2
Time Complexity
Test for Collisions Faster Partitioning
Put Every Object into a CellTest Adjacent Cells
Plane SweepTest Objects who have colliding planes
Terrain Collisions
How to test for collisions within a 3d landscape
Most terrains are height mapsNo Cliffs, or Overhead TerrainUsed in Oblivion, Half-life 2 & Supreme
Commander Non-Uniform Terrains (TINs)
Polygon Meshes for terrain, ex. Caves, interiors.
Triangulated Irregular Networks
Irregular meshes can still be parsed using oct-trees.
Oct-trees are useful, because they subdivide into smaller segments. So knowing which oct-tree your in allows the engine to search within in, until the correct polygon is found.
Also can be used to make simpler geometry for distant scenery.