Which is better for collision detection AABB or bounding spheres?
Bounding spheres. Using bounding spheres to detect collisions is a bit more complex than AABB, but still fairly quick to test. The main advantage of spheres is that they are invariant to rotation, so if the wrapped entity rotates, the bounding sphere would still be the same.
How to check if a point is inside an AABB?
Checking if a point is inside an AABB is pretty simple — we just need to check whether the point’s coordinates fall inside the AABB; considering each axis separately.
How can I change the size of an AABB?
If you have entities that will be rotating, you can either modify the dimensions of the bounding box so it still wraps the object, or opt to use another bounding geometry type, such as spheres (which are invariant to rotation.) The animated GIF below shows a graphic example of an AABB that adapts its size to fit the rotating entity.
Which is the best algorithm for 3D collision detection?
Followup articles will cover implementations in specific 3D libraries. As with 2D collision detection, axis-aligned bounding boxes (AABB) are the quickest algorithm to determine whether the two game entities are overlapping or not.
How does collision detection work in physics engine?
The way a physics engine works is by creating a physical body, usually attached to a visual representation of it. This body has properties such as velocity, position, rotation, torque, etc., and also a physical shape. This shape is the one that is considered in the collision detection calculations.
Why is the Axis aligned constraint used in collision detection?
The axis-aligned constraint is there because of performance reasons. The overlapping area between two non-rotated boxes can be checked with logical comparisons alone, whereas rotated boxes require additional trigonometric operations, which are slower to calculate.
How to check if a sphere contains a point?
To check whether a sphere contains a point we need to calculate the distance between the point and the sphere’s center. If this distance is smaller than or equal to the radius of the sphere, the point is inside the sphere.