Find tangent direction of point ?

[CinnamonMetal]

How to find the tangent direction of a point ?

Edited April 30, 2019 by CinnamonMetal

[CinnamonMetal]

I should have said, how can I rotate a tangent vector ?

[kiryha]

To rotate vector (N) with matrix (you can also rotate vector with quaternions or euler):
 

// Set orientation vector: normal
@N = {1,0,0};
// create matrix
matrix3 matrx = ident();
float angle = -radians(chf('Rotation_Y'));
// rotate matrix
rotate(matrx, angle, {0,1,0});
// Apply rotation
@N *= matrx;

To create a vector from 2 points you just need to subtract their positions.  If you have only one point you can use origin as a second position.

[CinnamonMetal]

Ok, how do you get two vectors to point at each other, or that ties in with vector subtraction.

 

Edited April 30, 2019 by CinnamonMetal

[kiryha]

I did not understand your question, Christopher... 
But the position of a vector does not matter (if we are not speaking about the spetial type of vectors - positional vectors), you can move a vector anywhere in 3D space and it would be the same vector.  

[CinnamonMetal]

Thanks it helped