Hi all... More physics! (day 2 for me using Unity.. it rocks)

When you throw a dart point first, the drag on it is low. If you throw it with the point 90 degrees to the target it presents a different cross section to the air, and the drag increases.

I need Unity to understand this a little better, so I figured I could change rigidbody.drag based on the difference between heading and direction of movement.

Would I be subtracting Vector3's to get a difference? How then to convert that to simple degrees of deviation?

Conceptually simple... I think :) But in the end, euler degrees deviation is what I am searching for.

// Set this to be the "maximum drag", i.e. when
// the object is facing the wrong direction completely (rotation 180).
float maxDrag = 1;
// Offset angle is how much the object has
// rotated from "zero" in either direction, from 0 to 180.
float offsetAngle = (transform.eulerAngles.y + 180) % 180;
// Calculate ratio
float drag = (offsetAngle / 180) * maxDrag;
// Set drag here
rigidbody.drag = drag;