Trigger Enter Side on a cube

Questions & Answers
1

Hey guys,
I would like to detect the side on which a trigger was entered/exited.
I’m talking about a trigger in the shape of a cube.
Is there any function that returns the side of a cube on which it was entered.

Thanks.

2

When using a !IsTrigger collider, you could use the hit normal, but as you want to use a trigger, I can only suggest this imprecise approach in the OnCollision() method:

// Only works if not rotated or scaled: Vector3 delta = collider.gameObject.transform.position - gameObject.transform.position;
Vector3 delta = gameObject.transform.InverseTransformPoint(collider.gameObject.transform.position);
float xAbs = Mathf.Abs(delta.x);
float yAbs = Mathf.Abs(delty.y);
float zAbs = Mathf.Abs(delty.z);
if (xAbs > yAbs && xAbs > zAbs) {
    // side is hit
   if (delta.x < 0)
       // left
   else
       // right
} else if (zAbs > yAbs) {
   // front/back is hit
   if (delta.z > 0)
       // back
   else
      // front
} else {
    // top/bottom is hit
    if (delta.y > 0)
        // top
    else
        // bottom
}

But if you need it a little more precise I would add 5 empty children with flat trigger collider boxes for the 5 additional (to the 1 already defined in the parent) sides. I think the latter would be my approach. :slight_smile: