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graphics - How do you determine if a list of of points in 3D space are in clock-wise order?

point[0] = (0,1,1)
point[1] = (1,1,1)
point[2] = (0,0,1)
point[3] = (1,0,1)

For examples below, each point above maps to an index in the visualization below.

0----------1
|          |
|          |
|          |
3----------2
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You can't.

If the points are not coplanar, it is even impossible to define an orientation.

If the points are coplanar, you can look at their plane from both sides.


If you want this information with respect to an observer, project the vertices to the viewing plane (to reduce to 2D) and compute the algebraic area by the shoelace formula. The sign tells you the orientation.


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