Rotation vector in affine transformation

[marsha-c]

Hello,

Can someone please explain how the rotation vector input works in the EGS_AffineTransform Class Reference?

Thanks in advance :)

[ftessier]

Yes, this is not a very common way to define a rotation, but it is eminently useful! The rotation is defined as the rotation that transforms the input rotation vector to a vector along (0, 0, 1). The highlighted text above provides an example. To transform the vector (-1, 0, 1) so that it lies along the z-axis, you need a +45 degree rotation around the y-axis; hence (-1, 0, 1) in this way defines a +45 degree rotation around the y-axis.

[marsha-c]

Ah, I get it now! Thanks very much, Fred :)