Unity3d Box Collider Vertex - transform

Question

How do I get the vertexes of a box collider in world space in Unity3d? (with correct rotation and scale). Just doing local-world on the object does not work.
obj.transform.localToWorldMatrix.MultiplyPoint3x4(extents); and doing similar things for the other corners is what I tried.

Answer 1

Since you can easily get the BoxCollider's centre and extents you can get the local vertex position easily by adding or subtracting the extent from the centre, then transforming it into global world space with a method like Vector3.TransformPoint()
The following script prints the global position of each vertex of a BoxCollider attached to the same GameObject as the script, every Update() call.
using System.Collections;
public class DebugPrintColliderVertices : MonoBehaviour
{
const uint NUM_VERTICES = 8;
private BoxCollider boxCollider;
private Transform[] vertices;
void Awake()
{
boxCollider = (BoxCollider)this.gameObject.GetComponent(typeof(BoxCollider));
if (boxCollider == null)
{
Debug.Log ("Collider not found on " + this.gameObject.name + ". Ending script.");
this.enabled = false;
}
vertices = new Transform[NUM_VERTICES];
}
void Update()
{
Vector3 colliderCentre = boxCollider.center;
Vector3 colliderExtents = boxCollider.extents;
for (int i = 0; i != NUM_VERTICES ; ++i)
{
Vector3 extents = colliderExtents;
extents.Scale (new Vector3((i & 1) == 0 ? 1 : -1, (i & 2) == 0 ? 1 : -1, (i & 4) == 0 ? 1 : -1));
Vector3 vertexPosLocal = colliderCentre + extents;
Vector3 vertexPosGlobal = boxCollider.transform.TransformPoint(vertexPosLocal);
// display vector3 to six decimal places
Debug.Log ("Vertex " + i + " # " + vertexPosGlobal.ToString("F6"));
}
}
}
Note that the BoxCollider's size is multiplied by the transform.scale of the GameObject it's attached to. I haven't included that calculation in said script, but finding the overall rotation/scale should be fairly trivial from this point.