We also looked at this hard body, but as stated in the commentary, the real mechanism somehow will have a MyGameObject class with a position, orientation, OpenGL grid and a pointer in the hard body. The green field is a form of collision, in the same position and orientation, as a network. Although this form of collision can be the network itself, it is often a bad idea for performance. In this manual we use a physical-ball mechanism, but the concepts are exactly the same for everyone else: PhysX, Havok, etc. In addition, these functions are probably more optimized than yours: all motors use spatial separation structures that avoid the need to check for intersections with most objects that are not in the same area. The NDC is a cube centered in the center, so the radius of “passing through the mouse” in this space is a straight line perpendicular to the nearest plane! This makes the calculations of LRayStart_NDC and lEndStart_NDC so easy to calculate. The idea is that the game engine needs a physics engine anyway, and that all the physics engines have a function to trim the bar with the scene. Note that the rigid hull uses the collision shape to determine its shape. The first thing you need to do is to find the beam that starts in the camera and passes through the mouse.