I'm doing a computer vision program in which I have three coplanar points and I want to know their position at all times. In other words, I want to realize when there is translation and when there is rotation.
For the translation I have no problems (at least for now), but the rotation to the sides (right and left) is driving me crazy, I can not figure out how to calculate it.
Being 3 points I work it as a triangle, I am able to know the distance between sides, angles, heights and area of the triangle. But none of this works for me since the rotation to the left and the rotation to the right are always symmetrical and therefore the computer is not able to detect what direction it is. Do you know any method for this calculation without adding more points? I'm sure this has been solved before but I don't know what else to think.
Thank you so much
EDIT
It's not a duplicate of this question because my triangles are 2D. That is the problem, I'm working with 2D coplanar points. That's what's difficult to know if the rotation is to the left or to the right because the behaviour is symmetrical.
Hint.
Calculating the actual the barycenter and comparing with the former one, we can obtain a translation transformation. After that, assuming the common origin at the barycenter we can compute the rotational transformation.