private bool IsDetailedEnough(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
var distanceToCamera = (node.Bounds.Center - _cameraPosition).Length;
var screenSpaceError = (node.GeometricError / distanceToCamera) * _k;
return screenSpaceError <= _allowedScreenSpaceError;
}
public void Creates_root_node_with_no_leafs_at_zero_depth()
{
var sut = new ChunkedLodTreeFactory();
var expectedBounds = new Box3D(new Vector3d(-1, -2, -3), new Vector3d(1, 2, 3));
var result = sut.Create(expectedBounds, 0);
Assert.AreEqual(expectedBounds, result.Bounds);
Assert.AreEqual(1, result.GeometricError);
Assert.IsEmpty(result.Nodes);
}
public void Creates_root_node_with_four_children_at_depth_one()
{
var sut = new ChunkedLodTreeFactory();
var expectedBounds = new Box3D(new Vector3d(-1, -1, -1), new Vector3d(1, 1, 1));
var result = sut.Create(expectedBounds, 1);
Assert.AreEqual(expectedBounds, result.Bounds);
Assert.AreEqual(2, result.GeometricError);
Assert.AreEqual(4, result.Nodes.Length);
}
public void Creates_children_with_correct_bounds_and_are_leafs_at_depth_one()
{
var sut = new ChunkedLodTreeFactory();
var expectedBounds = new Box3D(new Vector3d(-1, -1, -1), new Vector3d(1, 1, 1));
var result = sut.Create(expectedBounds, 1);
AssertLeaf(new Box3D(new Vector3d(-1, -1, -1), new Vector3d(0, 0, 1)), result.Nodes[0]);
AssertLeaf(new Box3D(new Vector3d(0, -1, -1), new Vector3d(1, 0, 1)), result.Nodes[1]);
AssertLeaf(new Box3D(new Vector3d(-1, 0, -1), new Vector3d(0, 1, 1)), result.Nodes[2]);
AssertLeaf(new Box3D(new Vector3d(0, 0, -1), new Vector3d(1, 1, 1)), result.Nodes[3]);
}
public static ChunkedLodTreeFactory.ChunkedLodTreeNode CreateTree()
{
var chunkedLodTreeFactory = new ChunkedLodTreeFactory();
double width = 8192 * 2 * 2;
var bounds = new Bounds2D(
new Vector2d(-width / 2, -width / 2),
new Vector2d(width / 2, width / 2));
var chunkResolution = 32;
var depth = (int)Math.Log((width / chunkResolution), 2);
return(chunkedLodTreeFactory.Create(bounds, depth));
}
public static ChunkedLodTreeFactory.ChunkedLodTreeNode CreateTree()
{
var chunkedLodTreeFactory = new ChunkedLodTreeFactory();
double width = 8192 * 2 * 2;
var bounds = new Bounds2D(
new Vector2d(-width/2, -width/2),
new Vector2d(width/2, width/2));
var chunkResolution = 32;
var depth = (int)Math.Log((width / chunkResolution), 2);
return chunkedLodTreeFactory.Create(bounds, depth);
}
public void Creates_tree_for_depth_of_two()
{
var sut = new ChunkedLodTreeFactory();
var expectedBounds = new Box3D(new Vector3d(-1, -1, -1), new Vector3d(1, 1, 1));
var result = sut.Create(expectedBounds, 2);
Assert.AreEqual(4, result.GeometricError);
var leafs = result.Nodes.SelectMany(x => x.Nodes);
Assert.AreEqual(16, leafs.Count());
foreach (var leaf in leafs)
{
Assert.IsEmpty(leaf.Nodes);
}
}
private void CalculateVisibleNodes(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
if (!IsVisible(node))
return;
if (IsDetailedEnough(node) || node.IsLeaf())
{
_visibleNodes.Add(node);
return;
}
foreach (var child in node.Nodes)
{
CalculateVisibleNodes(child);
}
}
private bool IsVisible(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
var center = new Vector3d(node.Bounds.Center.X, node.Bounds.Center.Y, 0);
var delta = node.Bounds.Max - node.Bounds.Min;
var side = Math.Max(delta.X, delta.Y);
var radius = Math.Sqrt(side * side + side * side);
for (var i = 0; i < _frustumPlanes.Length; i++)
{
var sphereIsOutsideOfPlane = PlaneDistance(_frustumPlanes[i], center) < -radius;
if (sphereIsOutsideOfPlane)
{
return false;
}
}
return true;
}
public List<ChunkedLodTreeFactory.ChunkedLodTreeNode> Calculate(
ChunkedLodTreeFactory.ChunkedLodTreeNode root,
double viewportWidth,
double horizontalFieldOfView,
Vector3d cameraPosition,
double allowedScreenSpaceError,
Vector4d[] frustumPlanes)
{
_frustumPlanes = frustumPlanes;
_allowedScreenSpaceError = allowedScreenSpaceError;
_cameraPosition = cameraPosition;
_visibleNodes = new List<ChunkedLodTreeFactory.ChunkedLodTreeNode>();
_k = viewportWidth / (Math.Tan(horizontalFieldOfView / 2));
CalculateVisibleNodes(root);
return _visibleNodes;
}
private static ChunkedLodTreeFactory.ChunkedLodTreeNode CreateTree()
{
var chunkedLodTreeFactory = new ChunkedLodTreeFactory();
var bounds = new Box3D(
new Vector3d(-4096, -4096, 0),
new Vector3d(4096, 4096, 0));
var levels = Math.Log((8192 / 128), 2);
//calculate depth so that one square is one meter as maximum resolution
return chunkedLodTreeFactory.Create(bounds, (int)8);
}
private void CacheNode(ChunkedLodTreeFactory.ChunkedLodTreeNode node)
{
_cache.Add(node);
}
private void AssertLeaf(Box3D expected, ChunkedLodTreeFactory.ChunkedLodTreeNode actual)
{
Assert.IsEmpty(actual.Nodes);
Assert.AreEqual(1, actual.GeometricError);
Assert.AreEqual(expected, actual.Bounds);
}