private void Split()
{
//discard parent's resources
if (Parent != null)
{
Parent.DestroyNode();
}
//force too coarse neighbors to split as well
for (byte i = 0; i < 4; i++)
{
if (SplitLevel > Neighbors[i].Node.SplitLevel && !Neighbors[i].Node.HasChildren)
{
Neighbors[i].Node.Split();
return;
}
}
#region TOP LEFT
var volume1 = new PatchAABB();
volume1.Vertices.Add(Volume.Vertices[0]);
volume1.Vertices.Add(Vector3.Lerp(Volume.Vertices[0], Volume.Vertices[1], 0.5f));
volume1.Vertices.Add(Middle);
volume1.Vertices.Add(Vector3.Lerp(Volume.Vertices[3], Volume.Vertices[0], 0.5f));
var uv1a = Volume.UVs[0];
var uv1b = Vector3.Lerp(Volume.UVs[0], Volume.UVs[1], 0.5f);
var uv1d = Vector3.Lerp(Volume.UVs[3], Volume.UVs[0], 0.5f);
var uv1c = new Vector3(uv1b.x, uv1d.y, 0);
volume1.UVs.Add(uv1a);
volume1.UVs.Add(uv1b);
volume1.UVs.Add(uv1c);
volume1.UVs.Add(uv1d);
#endregion
#region TOP RIGHT
//second child - top right
var volume2 = new PatchAABB();
volume2.Vertices.Add(Vector3.Lerp(Volume.Vertices[0], Volume.Vertices[1], 0.5f));
volume2.Vertices.Add(Volume.Vertices[1]);
volume2.Vertices.Add(Vector3.Lerp(Volume.Vertices[1], Volume.Vertices[2], 0.5f));
volume2.Vertices.Add(Middle);
var uv2a = Vector3.Lerp(Volume.UVs[0], Volume.UVs[1], 0.5f);
var uv2b = Volume.UVs[1];
var uv2c = Vector3.Lerp(Volume.UVs[1], Volume.UVs[2], 0.5f);
var uv2d = new Vector3(uv2a.x, uv2c.y, 0);
volume2.UVs.Add(uv2a);
volume2.UVs.Add(uv2b);
volume2.UVs.Add(uv2c);
volume2.UVs.Add(uv2d);
#endregion
#region BOTTOM RIGHT
//third child - bottom right
var volume3 = new PatchAABB();
volume3.Vertices.Add(Middle);
volume3.Vertices.Add(Vector3.Lerp(Volume.Vertices[1], Volume.Vertices[2], 0.5f));
volume3.Vertices.Add(Volume.Vertices[2]);
volume3.Vertices.Add(Vector3.Lerp(Volume.Vertices[3], Volume.Vertices[2], 0.5f));
var uv3b = Vector3.Lerp(Volume.UVs[1], Volume.UVs[2], 0.5f);
var uv3c = Volume.UVs[2];
var uv3d = Vector3.Lerp(Volume.UVs[3], Volume.UVs[2], 0.5f);
var uv3a = new Vector3(uv3d.x, uv3b.y, 0);
volume3.UVs.Add(uv3a);
volume3.UVs.Add(uv3b);
volume3.UVs.Add(uv3c);
volume3.UVs.Add(uv3d);
#endregion
#region BOTTOM LEFT
//fourth child - bottom left
var volume4 = new PatchAABB();
volume4.Vertices.Add(Vector3.Lerp(Volume.Vertices[3], Volume.Vertices[0], 0.5f));
volume4.Vertices.Add(Middle);
volume4.Vertices.Add(Vector3.Lerp(Volume.Vertices[3], Volume.Vertices[2], 0.5f));
volume4.Vertices.Add(Volume.Vertices[3]);
var uv4a = Vector3.Lerp(Volume.UVs[3], Volume.UVs[0], 0.5f);
var uv4c = Vector3.Lerp(Volume.UVs[3], Volume.UVs[2], 0.5f);
var uv4d = Volume.UVs[3];
var uv4b = new Vector3(uv4c.x, uv4a.y, 0);
volume4.UVs.Add(uv4a);
volume4.UVs.Add(uv4b);
volume4.UVs.Add(uv4c);
volume4.UVs.Add(uv4d);
#endregion
var q1 = new PatchTree(this, volume1);
var q2 = new PatchTree(this, volume2);
var q3 = new PatchTree(this, volume3);
var q4 = new PatchTree(this, volume4);
//set internal neighbors
q1.SetNeighbor(PatchNeighborDirection.Bottom, q4, PatchNeighborDirection.Top);
q1.SetNeighbor(PatchNeighborDirection.Right, q2, PatchNeighborDirection.Left);
//set internal neighbors
q2.SetNeighbor(PatchNeighborDirection.Bottom, q3, PatchNeighborDirection.Top);
q2.SetNeighbor(PatchNeighborDirection.Left, q1, PatchNeighborDirection.Right);
//set internal neighbors
q3.SetNeighbor(PatchNeighborDirection.Top, q2, PatchNeighborDirection.Bottom);
q3.SetNeighbor(PatchNeighborDirection.Left, q4, PatchNeighborDirection.Right);
//set internal neighbors
q4.SetNeighbor(PatchNeighborDirection.Top, q1, PatchNeighborDirection.Bottom);
q4.SetNeighbor(PatchNeighborDirection.Right, q3, PatchNeighborDirection.Left);
//store as children of the current node
Children[0] = q1;
Children[1] = q2;
Children[2] = q3;
Children[3] = q4;
Sphere.Splitted = true;
HasChildren = true;
ReLink();
}
