public bool RayCast(Vector3 from, Vector3 to, RayCastCallback callback = null)
{
Vector3 r = to - from;
r.Normalize();
float maxFraction = 1.0f;
// v is perpendicular to the segment.
Vector3 v = VectorUtil.FindOrthogonal(r).normalized;
Vector3 absV = VectorUtil.Abs(v);
// build a bounding box for the segment.
Aabb rayBounds = Aabb.Empty;
rayBounds.Include(from);
rayBounds.Include(to);
m_stack.Clear();
m_stack.Push(m_root);
bool hitAnyBounds = false;
while (m_stack.Count > 0)
{
int index = m_stack.Pop();
if (index == Null)
{
continue;
}
if (!Aabb.Intersects(m_nodes[index].Bounds, rayBounds))
{
continue;
}
// Separating axis for segment (Gino, p80).
// |dot(v, a - c)| > dot(|v|, h)
Vector3 c = m_nodes[index].Bounds.Center;
Vector3 h = m_nodes[index].Bounds.HalfExtents;
float separation = Mathf.Abs(Vector3.Dot(v, from - c)) - Vector3.Dot(absV, h);
if (separation > 0.0f)
{
continue;
}
if (m_nodes[index].IsLeaf)
{
Aabb tightBounds = m_nodes[index].Bounds;
tightBounds.Expand(-FatBoundsRadius);
float t = tightBounds.RayCast(from, to, maxFraction);
if (t < 0.0f)
{
continue;
}
hitAnyBounds = true;
float newMaxFraction =
callback != null
? callback(from, to, m_nodes[index].UserData)
: maxFraction;
if (newMaxFraction >= 0.0f)
{
// Update segment bounding box.
maxFraction = newMaxFraction;
Vector3 newTo = from + maxFraction * (to - from);
rayBounds.Min = VectorUtil.Min(from, newTo);
rayBounds.Max = VectorUtil.Max(from, newTo);
}
}
else
{
m_stack.Push(m_nodes[index].ChildA);
m_stack.Push(m_nodes[index].ChildB);
}
}
return(hitAnyBounds);
}