鼠标的射线拾取功能，在模型的不同位置，拾取相对应的模型三角形；有注释,Pick up the mouse-ray features, the different locations in the model, pick up the model that corresponds to the triangle annotated

3D图形中射线的碰撞检测，射线与AABB，三角形，球的碰撞分析-3D graphics ray collision detection, ray and AABB, triangle, the ball' s collision analysis