   Can anyone explain little bit of Collision detection
  Hi I am a newbie in Opengl and graphic related stuff. I read some of the tutorial on the nehe.gamedev.net (I think I typed right) about the collision detection but it has abit too much for me to digest it. Is there a good website that explain very well on that? I know the collision detection is to prevent the two objects for overlapping. How do we detect it in real time? E.g. If the program have two balls hitting face to face, do I detect the collision just before it hits or do I detect the collision at the start as the program starts? I am abit confused. Thanks if anyone could help meSimon   
Quote:Original post by kbundyI know the collision detection is to prevent the two objects for overlapping. How do we detect it in real time? E.g. If the program have two balls hitting face to face, do I detect the collision just before it hits or do I detect the collision at the start as the program starts? I am abit confused.There are many different ways to perform collision detection; some are very simple, and some are quite complex.One way to classify collision detection algorithms is by whether they are discrete or continuous.Discrete means that you take a 'snapshot' of the objects and determine if and how they are intersecting at that instant; in other words, the way in which they're moving is not considered. Continuous means that the motion is considered, and in addition to determining if and how the objects overlap, we also determine when.Discrete tests have some limitations; for example, if objects are moving quickly relative to their size they can pass through other objects ('tunneling'). However, discrete algorithms are usually simpler and easier to code than their continuous counterparts, and are a good place to start.If you go to the articles section here on gdnet and look for the 'collision detection' section, you'll find some good introductory articles that explain several fundamental intersection tests involving circles, spheres, boxes, and planes. Checking out some of the articles in this section will probably answer many of your questions.   ;  Thanks for ur help   