I have a problem with this sentence: glVertex3f( 0.0f, 1.0f, 0.0f); glVertex3f(-1.0f,-1.0f, 0.0f); glVertex3f( 1.0f,-1.0f, 0.0f); in all OpenGL examples everything seems normalized, why? are the coords being scaled by some factor? thanks, tomer

No. These are not normalized vertices, these are just vertices that happen to have only ones and zeroes in them. It has no purpose besides being perhaps the most simple example one can give for coordinates.

Illco

Some day before,I have the same question.

I know it was control by these functions.

1./Orthographic Projection
void glOrtho(GLdouble left,GLdouble right,GLdouble bottom,GLdouble top,
　　　　　　GLdouble near,GLdouble far)

2./Perspective Projection
void glFrustum(GLdouble left,GLdouble Right,GLdouble bottom,GLdouble top,
　　　　　　GLdouble near,GLdouble far);


if you real understand this two functions,you can catch it.