The tutorial is fine but doesnt help me. Following (too simple) problem: I want to look at a rotating cube. What happens is, that I'm rotating around the cube. That means the cube looks sometimes dark and sometimes bright like the day and nightside of a planet. I've read the lighting part of the OpenGl-Redbook. They write that you have to put the "light position"-function different places to get different results. This seems totally intuitve and clear to me. E.g. to put it after a translation in the displayfunc produces a translation of the light source... But in my code the "position (Light 0) $= ..." call doesnt do anything. It doesnt matter where I put it in the code and it makes no difference what position in my room the lightsource gets. Everytime the animation looks equal to that before. I think I've forgotten something really important or some calls are not on the right place. Here is my code. The lightposition-call isnt in there but I tried every possible position in the code. The light-stuff is stolen from one of the GLUT examples. This example looks fine but doesnt have any animation. <haskell> myinit = do lighting $= Enabled light (Light 0) $= Enabled main = do ... initialDisplayMode $= [GLUT.Double, GLUT.RGBA, GLUT.Depth] ... myinit ... myReshape :: ReshapeCallback myReshape size@(Size w h) = do viewport $= (Position 0 0, size) matrixMode $= Projection loadIdentity perspective 60 ((fromIntegral w)/(fromIntegral h)) 0.01 100.0 lookAt (Vertex3 0 0 5) (Vertex3 0 0 0) (Vector3 0 1 0) matrixMode $= Modelview 0 loadIdentity myDisplay :: IORef GLfloat ->DisplayCallback myDisplay arg = do angle <- readIORef arg clear [ColorBuffer, DepthBuffer] matrixExcursion $ do rotatef angle (Vector3 1 1 (1::GLfloat)) stdCube swapBuffers </haskell> I dont know if this mailinglist supports atachments but here to pics of this cube at day and night :-) Greetings Patrick
