How can I get a direction vector from a an Euler angle?

Question

Im trying to get a directional vector from an euler angle. But im not getting how to do it. This is what i got so far.

escapeAngle += 90;
var radians = escapeAngle * (Mathf.PI / 180);

var escapeAngleAsDirectionVector = new Vector2 ();
escapeAngleAsDirectionVector.x = Mathf.Cos (radians);
escapeAngleAsDirectionVector.y = Mathf.Sin (radians);

escapeAngleAsDirectionVector = transform.TransformPoint (escapeAngleAsDirectionVector);

Answer 1

You can create a rotation quaternion from your Euler angles. By multiplying it with a vector 'right', you get a Vector2:

Vector2 v = Quaternion.Euler(x, y, z) * Vector2.right

Answer 2

The correct formula is V = {r*cos(theta), y*sin(theta)} to get a vector from an angle with line at angle theta of length r, so your calculations look right. BUT one thing you need to account for is if the angle is negative. then you would have to add 360 to the angle.

E.g.

if(esacapeAngle < 0)
    escapeAngle += 360;

Another thing you should probably check if the angle is greater than or equal to 360 after the addition, because that wouldn't be valid either.

if(escapeAngle >= 360)
    throw error

then do the rest of your calculations.

This will give you a perpendicular vector though, as you add 90 to the angle.

Converting Polar coordinates to Cartesian coordinates