How to rotate your angle to someones position (In lua)?

Question

Let's say that we have function setAngle(x,y,z) which works perfectly. Now we also have position of ourself and a chicken. How can we use setAngle() to aim the chicken? This would be done in an fps game? I have no idea on how to convert the positions to the angle... >.<

Answer 1

There is math? Let be yourself at point

A(x, y, z)

and the chicken at

B(x, y, z)

A is part of plane E; its points satisfying the equation

a * x + b * y + c * z = d

Considering your game, E is possibly parallel to the XY-plane, so we have

E : c * z = d

Then, the angle enclosed by vector AB and the XY-plane is the arcsin of

c * ( B[z] - A[z] ) / ( mag(n) * mag(AB) )

where mag(n) is the magnitude of the surface normal of E resp. of the vector AB.

Considering your function, this might proof unnecessary, for it seems to me like adjusting things for you already.

Answer 2

It is the aTan of the slope of the line between you and the chicken. Use aTan2 though, it will work better regarding vertical directions (Thanks lhf)