If you want an object to rotate properly about its own axis transformations must be carried out in it’s own axis. My method is to store the position vector and global axis vectors in local space for each object and rotate translate them in the opposite direction every time the objects stats are changed. Then using the dot-product with the position vector and each of the global axis vectors the position of the object can be found. How do I find the angles of the spaceship for the glrotatef function and/or the vectors to rotate around. Or, is there another, better way of using local space that still allows proper rotation.
You have built a mountain out of a flattened molehill.
OpenGL transformations are done in the “local” coordinate system. If you want to display two spaceships and light them, you do it like this:
glMatrixMode( GL_MODELVIEW ); glLoadIdentity(); gluLookAt(); glPushMatrix(); // Save world space glTranslate(); // Move to the light's location glRotate(); // Rotate around the translated origin SetLight(); // Make a light glPopMatrix(); // Restore world space glPushMatrix(); // Save world space glTranslate(); // Move to the ship's location glRotate(); // Rotate around the translated origin DrawShip1(); // Draw ship 1 glPopMatrix(); // Restore world space glPushMatrix(); // Save world space glTranslate(); // Move to the ship's location glRotate(); // Rotate around the translated origin DrawShip2(); // Draw ship 2 glPopMatrix(); // Restore world space .... glFlush();
Note that the translation call is before the rotation. If the translation is after the rotation, it occurs in the rotated coordinate system.
Now, figuring out what the glRotate() parameters are is going to take some research.
Thank you for replying to my topic. Not without some considerable degree of effort Ihave now finally solved the problem using quaternions. Thank you for your help