the question is: "I raycast a body and get the point where the line meet the body. How can i know if the point is on arm, on a leg, excc..?". The aim of a physics engine is to simulate physics, not to get wich part of your body the point in inside. However no wrppers implementing this feature. but you may use joint (with ms3d or x, irrlicht support these joint file format only). Create a joint for arm, a joint for hand, a joint for the head, exc... Then raycast the line and find the point. Get ALL joint of your node. For ALL the joint get the respective bounding box. the recursive call irr::core::aabbox3d::isPointInside and pass the point to check in wich joint the point is inside
However this is not the aim of a physics engine\a wrapper
2)
This is possibleAlso, can you set your own callback functions for when specific objects collide?? Like if I make an asteroid game, if I want the asteroids to bounce off of each other, that shouldn't be too hard, but if when they hit the ship, I need to damage the ship, then I'd need my own callback function right
- create two materials, one for the spaceship one for the asteroids (IWorld::createMaterial and IBody::setMaterial)
- see IMaterial::setCollisionCallback function. IrrNewt will call your own functions when the asteroids collide with the spaceship
3)irrnewt don't apply gravity by default. if you want gravity you need to add your own force by calling the proper function (addForceContinuous) So if you write nothing irrnewt doesn't apply gravity for default