How can I rotate a shape in 2D space?

AI Thread Summary
To rotate a shape in 2D space, one must use a rotation matrix that involves the cosine and sine of the desired angle, theta. The transformation is expressed as [x'; y'] = [cos(theta) sin(theta); -sin(theta) cos(theta)][x; y]. Before applying this formula, it's essential to clarify how the shape is encoded and represented in terms of its position and angle. Understanding the unit circle concept can aid in visualizing the rotation process. Properly encoding the shape's information is crucial for accurate rotation.
fcs04001
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How do I rotate some shape in 2d space? That is, what factor do I multiply the x and y components to rotate my shape?

Thanks.
 
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fcs04001 said:
How do I rotate some shape in 2d space? That is, what factor do I multiply the x and y components to rotate my shape?

Thanks.

Sin of (y) and Cos of (x)

Think of a unit circle ( a cicle of Radius 1 around the origin)
 
Before we can answer that unambiguously, you must first of all explain how you "encode" your shape, that is: how you store the information about your shape and how you "draw" it, or specify its position and angle.

--------
Assaf
http://www.physicallyincorrect.com/"
 
Last edited by a moderator:
I got it:
[x'; y'] = [cos(theta) sin(theta); -sin(theta) cos(theta)][x; y]

Thanks.
 

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