如何在JOGL中旋转圆柱体

Question

I have drawn a wire cylinder in JOGL and I want to make it stand up when it is coming out of the screen?

I've been messing around with the following code in order to do the rotate but it is not rotating:

gl.glRotatef(cylinder_a, 0, 0, 90);

What is the correct way to rotate a cylinder in JOGL?

Answer 1

According to the JOGL documentation for gl.glRotatef its arguments are angle , x , y , z . With the arguments 0 , 0 , 90 for x, y, z, you are defining the vector along +z, pointing out of the screen. This means that you are rotating the cylinder about its axis, so the change isn't apparent. To make it stand "upright" you need to rotate it around the x axis.

(You can change the way x, y, and z point in OpenGL, but usually +x points right, +y point up, and +z "comes out" from the screen. You can use the right hand rule to remember that.)