Shape-based Hit Detection in 8

"A while back I posted a demo of shape-based hit detection in Flash 8. At the time, I wasn't allowed to post the source code, but promised I would later. So here it is.

The com.gskinner.sprites.CollisionDetection class is really simple to work with, there is a single static method called checkForCollision with four parameters:"

Recursive Dimensional Clustering

"Collision detection can be done in many ways. The most straightforward and simplest way is to just test every object against all other objects. Because every object has to test only for others after it in the list of objects, and testing an object with itself is useless, we arrive at the well known brute force comparison algorithm:"

Motor Physics: Collision Demo

"Collisions are resolved using a very simple but fast method which doesn't support rotational effects - basically the collision model just applies an impulse based on the velocities and masses of both bodies along the normal of collision to separate them, and computes some sort of dynamic friction along the normals tangential component. A restitution factor is used to simulate energy loss (blend between perfect elastic and inelastic collisions)."

Neat demo of an alternate way to detect collisions.

Drunken Ragdolls

"Sumotori Dreams is a small demoscene game created by Peter Sotesz for the Breakpoint 2007 96k game competition (it took first). The premise is simple: two self-balancing physics rigs face off in a sumo ring. The first rig to fall over loses. The implementation is simple but satisfying, and is well supported by solid physics, decent lighting, and good camera work. You can play against a computer opponent, but the real fun is playing Sumotori against a friend on the same keyboard."

Gravity Probe B is a success

"Conceived by Stanford Professors Leonard Schiff, William Fairbank and Robert Cannon in 1959 and funded by NASA in 1964, GP-B is the longest running, continuous physics research program at both Stanford and NASA."

The experiment has finally come to an end, confirming Einstein's original predictions about the warping of space time around the Earth, specifically "frame-dragging".