# Collision

## Methods

- Rigid vs. non-rigid
- Rigid bodies do not deform on impact
- Non-rigid bodies (or soft bodies) change shape

- Polygon vs. non-polygon
- Convex and non-convex
- Convex objects cannot get stuck on each other
- Non-convex objects can hook twist around other objects
- Breaks many nice geometric properties

- Voronoi diagrams
- Map regions to nearest points
- Separating axis theorem

- Minkoski sum
- Result of adding two shapes
- Can represent the region that is not free from collisions

- Sweeping volumes
- Integrate object position over time to produce volume
- Intersections in volumes represent collisions

## Acceleration

- Broad phase
- Find which objects need to be tested

- Narrow phase
- AABB vs. OBB
- Similar to ray tracing
- Trade off with speed and accuracy

- Geometric partitions
- Volumetric bounding
- Objects move through the regions
- Iterate sort, insertion into hierarchy