glRotatef

I don’t quite understand how glRotatef works

the first parameter is the angle and the rest 3 are the axes

how are the axes affected by changing the 3 parameters?

does anyone have a picture to help me understand?

Hi kiwon,

the first parameter is the rotation angle, that’s correct. The rest are the x, y and z coordinate of the axis around which you want your objects to rotate. So if you want to rotate around the x axis, you use glRotatef(angle, 1, 0, 0).

You could give more information about what you want to achieve. It’s hard to tell what you don’t understand.

Maybe you have a look at http://www.opengl.org/sdk/docs/man/xhtml/glRotate.xml for further explanation.

hi,

just think of the 3 parameters to be a line from 0,0,0

so you have x=3,y=2,z=4 => so think of a line from 0,0,0 to 3,2,4…

and now you just rotate the amount fo angle around this line …

if angle is negativ than you just rotate the other way …

think about: if you spin a ring around your finger it can always only be spined around the axis the finger is repesenting…
its the same with glrotate.

hope that helps
cu
uwi