public OctreeNode(OctreeNodeType _type)
{
Type = _type;
min = Vec3.Zero;
size = 0;
drawInfo = new OctreeDrawInfo();
children = new OctreeNode[8];
for (var i = 0; i < 8; i++)
{
children[i] = null;
}
}
static OctreeNode SimplifyOctree(OctreeNode node, double threshold)
{
if (node == null)
{
return(null);
}
if (node.Type != OctreeNodeType.Node_Internal)
{
// can't simplify!
return(node);
}
var qef = new QefSolver();
var signs = new int[8] {
-1, -1, -1, -1, -1, -1, -1, -1
};
var midsign = -1;
var edgeCount = 0;
var isCollapsible = true;
for (var i = 0; i < 8; i++)
{
node.children[i] = SimplifyOctree(node.children[i], threshold);
if (node.children[i] != null)
{
var child = node.children[i];
if (child.Type == OctreeNodeType.Node_Internal)
{
isCollapsible = false;
}
else
{
qef.add(child.drawInfo.qef);
midsign = (child.drawInfo.corners >> (7 - i)) & 1;
signs[i] = (child.drawInfo.corners >> i) & 1;
edgeCount++;
}
}
}
if (!isCollapsible)
{
// at least one child is an internal node, can't collapse
return(node);
}
Vec3 qefPosition;
qef.solve(out qefPosition, QEF_ERROR, QEF_SWEEPS, QEF_ERROR);
var error = qef.getError();
// convert to glm vec3 for ease of use
var position = new Vec3(qefPosition.X, qefPosition.Y, qefPosition.Z);
// at this point the masspoint will actually be a sum, so divide to make it the average
if (error > threshold)
{
// this collapse breaches the threshold
return(node);
}
if (position.X < node.min.X || position.X > (node.min.X + node.size) ||
position.Y < node.min.Y || position.Y > (node.min.Y + node.size) ||
position.Z < node.min.Z || position.Z > (node.min.Z + node.size))
{
position = qef.getMassPoint();
}
// change the node from an internal node to a 'psuedo leaf' node
var drawInfo = new OctreeDrawInfo();
drawInfo.corners = 0;
drawInfo.index = -1;
for (var i = 0; i < 8; i++)
{
if (signs[i] == -1)
{
// Undetermined, use centre sign instead
drawInfo.corners |= (midsign << i);
}
else
{
drawInfo.corners |= (signs[i] << i);
}
}
drawInfo.averageNormal = Vec3.Zero;
for (var i = 0; i < 8; i++)
{
if (node.children[i] != null)
{
var child = node.children[i];
if (child.Type == OctreeNodeType.Node_Psuedo ||
child.Type == OctreeNodeType.Node_Leaf)
{
drawInfo.averageNormal += child.drawInfo.averageNormal;
}
}
}
drawInfo.averageNormal = drawInfo.averageNormal.Normalized;
drawInfo.position = position;
drawInfo.qef = qef.getData();
for (var i = 0; i < 8; i++)
{
DestroyOctree(node.children[i]);
node.children[i] = null;
}
node.Type = OctreeNodeType.Node_Psuedo;
node.drawInfo = drawInfo;
return(node);
}