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View Full Version : Does opengl use the left-hand or right-hand system by default?



hanz
03-23-2004, 10:25 PM
Hello, does opengl use the left-hand system or the right-hand system? Also, i figured out that if we're using the left-hand system, rotation will be clockwise, while in a right-hand system, rotation will be counterclockwise!! Is this right?

harsman
03-24-2004, 12:09 AM
OpenGL's default coordinate system is right handed, i.e positive z points out of the screen.

hanz
03-24-2004, 10:24 PM
thank you very much..

lapiz
03-26-2004, 04:20 AM
See "Appendix B" of OpenGL specification.
15. OpenGL does not force left- or right-handedness on any of its coordinates systems. Consider, however, the following conditions: (1) the object coordinate system is right-handed; (2) the only commands used to manipulate the model-view matrix are Scale (with positive scaling values only), Rotate, and Translate; (3) exactly one of either Frustum or Ortho is used to set the projection matrix; (4) the near value is less than the far value for DepthRange. If these conditions are all satisfied, then the eye coordinate system is righthanded and the clip, normalized device, and window coordinate systems are left-handed.