private bool ClipByPlane(Plane plane, WMesh originMesh, out WMesh slicedMesh, out WMesh remainedMesh)
{
slicedMesh = null;
remainedMesh = null;
List <WTriangle> bodyTris = originMesh.GetBodyTris();
List <WTriangle> slicedTris = new List <WTriangle>();
List <WTriangle> remainedTris = new List <WTriangle>();
List <WClipEdge> clipedEdges = new List <WClipEdge>();
//Plane clipPlane = new Plane(plane.normal, Vector3.zero);
Plane clipPlane = plane;
for (int i = 0; i < bodyTris.Count; i++)
{
WTriangle tri = bodyTris[i];
Vector3 worldPos = Target.GetPosition();
// Using modified Sutherland-Hodgman
Vector3 a = tri.a + worldPos;
Vector3 b = tri.b + worldPos;
Vector3 c = tri.c + worldPos;
float da = clipPlane.GetDistanceToPoint(a);
float db = clipPlane.GetDistanceToPoint(b);
float dc = clipPlane.GetDistanceToPoint(c);
if (WMath.InFront(da) && WMath.InFront(db) && WMath.InFront(dc))
{
slicedTris.Add(tri);
}
else if (WMath.Behind(da) && WMath.Behind(db) && WMath.Behind(dc))
{
remainedTris.Add(tri);
}
else if (WMath.InFront(da) && WMath.InFront(db) && WMath.Behind(dc))
{
Vector3 ac = WMath.Intersect(a, c, da, dc);
Vector3 bc = WMath.Intersect(b, c, db, dc);
slicedTris.Add(new WTriangle(ac, a, b, worldPos));
slicedTris.Add(new WTriangle(b, bc, ac, worldPos));
remainedTris.Add(new WTriangle(ac, bc, c, worldPos));
clipedEdges.Add(new WClipEdge(ac, bc, worldPos));
}
else if (WMath.Behind(da) && WMath.Behind(db) && WMath.InFront(dc))
{
Vector3 ac = WMath.Intersect(a, c, da, dc);
Vector3 bc = WMath.Intersect(b, c, db, dc);
remainedTris.Add(new WTriangle(ac, a, b, worldPos));
remainedTris.Add(new WTriangle(b, bc, ac, worldPos));
slicedTris.Add(new WTriangle(ac, bc, c, worldPos));
clipedEdges.Add(new WClipEdge(bc, ac, worldPos));
}
else if (WMath.InFront(da) && WMath.Behind(db) && WMath.InFront(dc))
{
Vector3 ab = WMath.Intersect(a, b, da, db);
Vector3 bc = WMath.Intersect(b, c, db, dc);
slicedTris.Add(new WTriangle(a, ab, c, worldPos));
slicedTris.Add(new WTriangle(ab, bc, c, worldPos));
remainedTris.Add(new WTriangle(ab, b, bc, worldPos));
clipedEdges.Add(new WClipEdge(bc, ab, worldPos));
}
else if (WMath.Behind(da) && WMath.InFront(db) && WMath.Behind(dc))
{
Vector3 ab = WMath.Intersect(a, b, da, db);
Vector3 bc = WMath.Intersect(b, c, db, dc);
remainedTris.Add(new WTriangle(a, ab, c, worldPos));
remainedTris.Add(new WTriangle(ab, bc, c, worldPos));
slicedTris.Add(new WTriangle(ab, b, bc, worldPos));
clipedEdges.Add(new WClipEdge(ab, bc, worldPos));
}
else if (WMath.Behind(da) && WMath.InFront(db) && WMath.InFront(dc))
{
Vector3 ab = WMath.Intersect(a, b, da, db);
Vector3 ac = WMath.Intersect(a, c, da, dc);
slicedTris.Add(new WTriangle(ab, b, c, worldPos));
slicedTris.Add(new WTriangle(c, ac, ab, worldPos));
remainedTris.Add(new WTriangle(ac, a, ab, worldPos));
clipedEdges.Add(new WClipEdge(ab, ac, worldPos));
}
else if (WMath.InFront(da) && WMath.Behind(db) && WMath.Behind(dc))
{
Vector3 ab = WMath.Intersect(a, b, da, db);
Vector3 ac = WMath.Intersect(a, c, da, dc);
remainedTris.Add(new WTriangle(ab, b, c, worldPos));
remainedTris.Add(new WTriangle(c, ac, ab, worldPos));
slicedTris.Add(new WTriangle(ac, a, ab, worldPos));
clipedEdges.Add(new WClipEdge(ac, ab, worldPos));
}
}
MakeCap(clipedEdges, out List <WTriangle> slicedCap, out List <WTriangle> remainedCap);
if (slicedTris.Count > 0 && remainedTris.Count > 0)
{
slicedMesh = new WMesh(slicedTris, slicedCap);
remainedMesh = new WMesh(remainedTris, remainedCap);
return(true);
}
else
{
return(false);
}
}