public PSI_Plane[] GetFacePlanes()
{
// Generating a returning the box faces as planes.
var facePlanes = new PSI_Plane[6];
facePlanes[0] = new PSI_Plane(pPosition - transform.right * pSize.x * 0.5f, this.transform.rotation * Quaternion.Euler(0, 0, 90), new Vector2(pSize.y, pSize.z));
facePlanes[1] = new PSI_Plane(pPosition - transform.up * pSize.y * 0.5f, this.transform.rotation * Quaternion.Euler(0, 0, 180), new Vector2(pSize.x, pSize.z));
facePlanes[2] = new PSI_Plane(pPosition + transform.right * pSize.x * 0.5f, this.transform.rotation * Quaternion.Euler(0, 0, -90), new Vector2(pSize.y, pSize.z));
facePlanes[3] = new PSI_Plane(pPosition + transform.up * pSize.y * 0.5f, this.transform.rotation * Quaternion.Euler(0, 0, 0), new Vector2(pSize.x, pSize.z));
facePlanes[4] = new PSI_Plane(pPosition + transform.forward * pSize.z * 0.5f, this.transform.rotation * Quaternion.Euler(90, 0, 0), new Vector2(pSize.x, pSize.y));
facePlanes[5] = new PSI_Plane(pPosition - transform.forward * pSize.z * 0.5f, this.transform.rotation * Quaternion.Euler(-90, 0, 0), new Vector2(pSize.x, pSize.y));
return(facePlanes);
}
public static bool BoxBoxCollisionOccured(PSI_Collider_Box col1, PSI_Collider_Box col2, out Vector3 point)
{
point = Vector3.zero;
// Determine the axis to check during SAT.
var col1Axes = col1.GetAxes();
var col2Axes = col2.GetAxes();
var axesToCheck = new Vector3[]
{
col1Axes[0],
col1Axes[1],
col1Axes[2],
col2Axes[0],
col2Axes[1],
col2Axes[2],
Vector3.Cross(col1Axes[0], col2Axes[0]),
Vector3.Cross(col1Axes[0], col2Axes[1]),
Vector3.Cross(col1Axes[0], col2Axes[2]),
Vector3.Cross(col1Axes[1], col2Axes[0]),
Vector3.Cross(col1Axes[1], col2Axes[1]),
Vector3.Cross(col1Axes[1], col2Axes[2]),
Vector3.Cross(col1Axes[2], col2Axes[0]),
Vector3.Cross(col1Axes[2], col2Axes[1]),
Vector3.Cross(col1Axes[2], col2Axes[2])
};
// Determine the verts to check during SAT.
var col1Verts = col1.GetVertices();
var col2Verts = col2.GetVertices();
// Determine if the boxes are colliding using SAT.
Vector3 minOverlapAxis = Vector3.zero;
float minOverlap = 0f;
bool isColliding = CheckForOverlapUsingSAT(axesToCheck, col2Verts, col1Verts, out minOverlapAxis, out minOverlap) ||
CheckForOverlapUsingSAT(axesToCheck, col1Verts, col2Verts, out minOverlapAxis, out minOverlap);
if (isColliding)
{
// Estimate the collision point by converting the box faces to planes and projecting the vertices of the other
// box onto them. The projection points with the smallest distance are averaged to give the collision point.
var facePlanes = new PSI_Plane[][] { col1.GetFacePlanes(), col2.GetFacePlanes() };
var verts = new Vector3[][] { col1Verts, col2Verts };
var contactPoints = new List <Vector3>();
float contactPointDist = float.PositiveInfinity;
for (int i = 0; i < 2; i++)
{
foreach (var plane in facePlanes[i])
{
foreach (var vert in verts[1 - i])
{
float projectionDist = float.PositiveInfinity;
if (plane.PointProjectsOntoPlane(vert, out projectionDist))
{
projectionDist = Mathf.Abs(projectionDist);
if (Mathf.Abs(projectionDist - contactPointDist) < float.Epsilon)
{
contactPoints.Add(vert);
}
else if (projectionDist < contactPointDist)
{
contactPoints.Clear();
contactPoints.Add(vert);
contactPointDist = projectionDist;
}
}
}
}
}
point = Vector3.zero;
foreach (var contactPoint in contactPoints)
{
point += contactPoint;
}
point /= contactPoints.Count;
// Resolve any overlap between the boxes.
var collisionAxis = CorrectCollisionAxisDirection(col2.pPosition, col1.pPosition, minOverlapAxis);
ResolveCollisionOverlaps(col1, col2, collisionAxis, minOverlap);
// Calculate and apply the collision impulse to the boxes.
ApplyImpulses(col1, col2, collisionAxis, point);
return(true);
}
return(false);
}
