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Getting a vector having dimension rotations.

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Well, I want to make a vector out of rotations, for example, if I have RotX = 0 RotY = 90 RotZ = 0 the unit vector that would come out would be(i think) v.x = 0 v.y = 0 v.z = 1 How could I come on accomplishing this? I figured how to do it in 2D angles, since the hypothenus is always a length of 1, then we can get side A and side B with: sin(angle) = A cos(angle) = B this way, i could create a vector like so v.x = cos(angle) v.y = sin(angle) but, when it comes to 3 dimensions, how could i go on accomplishing my objectives?

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And so the sticking point starts...
There are different ways to play with things in 3d.
The 3rd dimension adds lots of complexity.

There are a few methods: euler rotation, axis-angle, and quaternions.

You can compose a complete 4x4 matrix for rotation, translation, and scaling based on euler rotation I believe.

The code here assumes rotation around a given axis(kind of)
theta is the YZ plane rotation or around the Z axis.
phi is XZ plane rotation or around Y.
phi is YZ plane rotation or around X.

x'' = y * sin(theta) + x * cos(theta)
y'' = y * cos(theta) - x * sin(theta)
z'' = z

x'''' = x'' * sin(phi) + x'' * cos(phi)
y'''' = y''
z'''' = z'' * cos(phi) - z'' * sin(phi)

x'''''' = x''''
y'''''' = y'''' * sin(chi) + y'''' * cos(chi)
z'''''' = z'''' * cos(chi) - z'''' * sin(chi)

This is the easiest method to derive.
It also is somewhat like the OpenGL glRotate() call.

For high-quality code, quaternions are the method of choice for rotations.(Last I checked- its kind of a debate thing)

Hope that helped...



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