Find what object is ahead of other

Questions & Answers
1

I have two game objects heading in relatively the same direction. How can I figure out which one is in front and which is behind?

For example, if you look at the image, B would be considered behind and A ahead.

alt text

2

Oh, found my own answer: http://forum.unity3d.com/threads/53188-how-do-i-detect-if-an-object-is-in-front-of-another-object

To summarize those posts:

var heading : Vector3 = a.position - b.position;
var dProduct = Vector3.Dot(heading, a.forward);
if (dProduct > 0) {
   // a is ahead
} else if (dProduct < 0) {
   // b is ahead
} else {
   // side by side
}