/**
* Returns geometry corresponding to volume @a that is divided into
* two separate pieces by @b. Return results in the form of two BSPTree
* instances: @side and @side2.
*/
public static void Slice(BSPTree a, BSPTree b, out BSPTree side1, out BSPTree side2)
{
side1 = a.Clone();
BSPTree bClone = b.Clone();
List <Triangle> side1Discarded = new List <Triangle>();
bClone.Invert();
bClone.ClipByTree(a, false);
side1.ClipByTree(b, true, side1Discarded);
side1.AddTriangles(bClone.GetAllTriangles());
bClone.Invert();
side2 = new BSPTree();
side2.AddTriangles(bClone.GetAllTriangles());
side2.AddTriangles(side1Discarded);
}
/**
* Returns geometry corresponding to volume that is occupied by @a,
* but not by @b.
*/
public static BSPTree Subtract(BSPTree a, BSPTree b)
{
BSPTree aClone = a.Clone();
BSPTree bClone = b.Clone();
float startTime = Time.realtimeSinceStartup;
bClone.Invert();
bClone.ClipByTree(a, false);
aClone.ClipByTree(b);
aClone.AddTriangles(bClone.GetAllTriangles());
return(aClone);
}
/**
* Returns geometry corresponding to volume @a that is divided into
* two separate pieces by @b, but @b is treated as a plane (the first split plane
* from the first node is used for splitting).
*
* Return results in the form of two List<Triangle> instances: @side and @side2.
*/
public static void FastSlice(BSPTree a, BSPTree b, out List <Triangle> side1, out List <Triangle> side2)
{
side1 = null;
side2 = null;
BSPTree bClone = b.Clone();
float startTime = Time.realtimeSinceStartup;
bClone.ClipByTree(a, false);
float clipTime = Time.realtimeSinceStartup - startTime;
List <Triangle> aTriangles = a.GetAllTriangles();
List <Triangle> bTriangles = bClone.GetAllTriangles();
bClone.Invert();
List <Triangle> bInvertedTriangles = bClone.GetAllTriangles();
if (bTriangles.Count > 0)
{
Plane splitPlane = bTriangles[0].OrientationPlane;
side1 = new List <Triangle>();
side2 = new List <Triangle>();
var coplanar = new List <Triangle>();
for (int i = 0; i < aTriangles.Count; i++)
{
Triangle tri = aTriangles[i];
Partitioner.SliceTriangle(tri, splitPlane, side1, side2, coplanar, coplanar);
}
side1.AddRange(bTriangles);
side2.AddRange(bInvertedTriangles);
}
else
{
side1 = aTriangles;
side2 = null;
}
}