Hi! I have tried to draw cylinders using the function gluCylinder of “GL Utility library”. It’s pretty easy but I have gotten some problems because it draws a cylinder directly on the Z-axis, so, I must make some rotation before draw a cylinder in any axis.

I tryed to make 2 consecutive rotations, first in Y-Axis and then in the X-Axis, if I had the right angles, it should be enough to draw in any direction with the “gluCylinder” function.

The problem is that it doesn´t work when a have a cylinder, for instance, from the point P1( 0, 0, 0 ) to the point P2( 100, 100, 100 ), I have not been able to calculate the right angle to make the right rotation before call gluCylinder.

I did that : angleY = arctan[(p2.X - p1.X) / (p2.Z - p1.Z)];

angleX = arctan[(p2.Y - p1.Y) / (p2.Z - p1.Z)];

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Seems that the angleY is right, but the angleX is not.
If somebody could help me, showing how to calculate these angles, would be very nice.
Thanks a lot.
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Rogerio Brasiliense

Florianópolis - Brazil