public void TestBvhClosestIntersection()
{
// for this shape imagine the 8 corners of a Rubik's cube and the center
var data = new List <BvhTreeItemData <int> >();
// left, front, bottom
data.Add(new BvhTreeItemData <int>(0, new AxisAlignedBoundingBox(0, 0, 0, 1, 1, 1)));
// right, front, bottom
data.Add(new BvhTreeItemData <int>(1, new AxisAlignedBoundingBox(2, 0, 0, 3, 1, 1)));
// left, back, bottom
data.Add(new BvhTreeItemData <int>(2, new AxisAlignedBoundingBox(0, 2, 0, 1, 3, 1)));
// right, back, bottom
data.Add(new BvhTreeItemData <int>(3, new AxisAlignedBoundingBox(2, 2, 0, 3, 3, 1)));
// center, center, center
data.Add(new BvhTreeItemData <int>(4, new AxisAlignedBoundingBox(1, 1, 1, 2, 2, 2)));
// left, front, top
data.Add(new BvhTreeItemData <int>(5, new AxisAlignedBoundingBox(0, 0, 2, 1, 1, 3)));
// right, front, top
data.Add(new BvhTreeItemData <int>(6, new AxisAlignedBoundingBox(2, 0, 2, 3, 1, 3)));
// left, back, top
data.Add(new BvhTreeItemData <int>(7, new AxisAlignedBoundingBox(0, 2, 2, 1, 3, 3)));
// right, back, top
data.Add(new BvhTreeItemData <int>(8, new AxisAlignedBoundingBox(2, 2, 2, 3, 3, 3)));
var bvhBuilder = new TradeOffBvhConstructor <int>();
var tree = bvhBuilder.CreateNewHierachy(data);
Assert.AreEqual(7, tree.CountBranches(), "these must be split up into multiple bounds");
var hitInfo = tree.GetClosestIntersection(new Ray(new Vector3(-.5, .5, .5), Vector3.UnitX));
Assert.IsNotNull(hitInfo, "found a hit");
Assert.AreEqual(0, hitInfo.ClosestHitObject, "found the left front bottom");
Assert.AreEqual(.5, hitInfo.DistanceToHit);
Assert.AreEqual(new Vector3(0, .5, .5), hitInfo.HitPosition);
Assert.AreEqual(IntersectionType.FrontFace, hitInfo.HitType);
Assert.AreEqual(new Vector3(-1, 0, 0), hitInfo.NormalAtHit);
hitInfo = tree.GetClosestIntersection(new Ray(new Vector3(3.5, .5, .5), -Vector3.UnitX));
Assert.IsNotNull(hitInfo, "found a hit");
Assert.AreEqual(1, hitInfo.ClosestHitObject, "found the right front bottom");
Assert.AreEqual(.5, hitInfo.DistanceToHit);
Assert.AreEqual(new Vector3(3, .5, .5), hitInfo.HitPosition);
Assert.AreEqual(IntersectionType.FrontFace, hitInfo.HitType);
Assert.AreEqual(new Vector3(1, 0, 0), hitInfo.NormalAtHit);
hitInfo = tree.GetClosestIntersection(new Ray(new Vector3(-.5, 1.5, 1.5), -Vector3.UnitX));
Assert.IsNull(hitInfo, "Found no items.");
hitInfo = tree.GetClosestIntersection(new Ray(new Vector3(-.5, 1.5, 1.5), Vector3.UnitX));
Assert.AreEqual(4, hitInfo.ClosestHitObject, "Found only center.");
Assert.AreEqual(new Vector3(1, 1.5, 1.5), hitInfo.HitPosition);
Assert.AreEqual(IntersectionType.FrontFace, hitInfo.HitType);
Assert.AreEqual(new Vector3(-1, 0, 0), hitInfo.NormalAtHit);
}
public void TestBvhTreeSearches()
{
// for this shape imagine the 8 corners of a Rubik's cube and the center
var data = new List <BvhTreeItemData <int> >();
// left, front, bottom
data.Add(new BvhTreeItemData <int>(0, new AxisAlignedBoundingBox(0, 0, 0, 1, 1, 1)));
// right, front, bottom
data.Add(new BvhTreeItemData <int>(1, new AxisAlignedBoundingBox(2, 0, 0, 3, 1, 1)));
// left, back, bottom
data.Add(new BvhTreeItemData <int>(2, new AxisAlignedBoundingBox(0, 2, 0, 1, 3, 1)));
// right, back, bottom
data.Add(new BvhTreeItemData <int>(3, new AxisAlignedBoundingBox(2, 2, 0, 3, 3, 1)));
// center, center, center
data.Add(new BvhTreeItemData <int>(4, new AxisAlignedBoundingBox(1, 1, 1, 2, 2, 2)));
// left, front, top
data.Add(new BvhTreeItemData <int>(5, new AxisAlignedBoundingBox(0, 0, 2, 1, 1, 3)));
// right, front, top
data.Add(new BvhTreeItemData <int>(6, new AxisAlignedBoundingBox(2, 0, 2, 3, 1, 3)));
// left, back, top
data.Add(new BvhTreeItemData <int>(7, new AxisAlignedBoundingBox(0, 2, 2, 1, 3, 3)));
// right, back, top
data.Add(new BvhTreeItemData <int>(8, new AxisAlignedBoundingBox(2, 2, 2, 3, 3, 3)));
var bvhBuilder = new TradeOffBvhConstructor <int>();
var tree = bvhBuilder.CreateNewHierachy(data);
Assert.AreEqual(7, tree.CountBranches(), "these must be split up into multiple bounds");
var results = new List <int>();
tree.SearchBounds(new AxisAlignedBoundingBox(0, 0, 0, 3, 3, 3), results);
Assert.AreEqual(results.Count(), 9, "Found all items.");
results.Clear();
tree.SearchPoint(1.5, 1.5, 1.5, results);
Assert.AreEqual(1, results.Count(), "All or around this point.");
Assert.AreEqual(4, results[0], "found the center point.");
results.Clear();
tree.SearchBounds(new AxisAlignedBoundingBox(1.5, 1.5, 0, 3, 3, 3), results);
Assert.AreEqual(3, results.Count(), "All or around this point.");
Assert.IsTrue(results.Contains(4), "found the center point.");
Assert.IsTrue(results.Contains(8), "found the center point.");
Assert.IsTrue(results.Contains(3), "found the center point.");
}
public void TestBvhSimpleTreeSearches()
{
var data = new List <BvhTreeItemData <int> >();
data.Add(new BvhTreeItemData <int>(1, new AxisAlignedBoundingBox(-10, -20, -30, 10, 20, 30)));
data.Add(new BvhTreeItemData <int>(2, new AxisAlignedBoundingBox(-9, -18, -29, 9, 19, 29)));
data.Add(new BvhTreeItemData <int>(3, new AxisAlignedBoundingBox(-9, -17, -29, 9, 19, 28)));
data.Add(new BvhTreeItemData <int>(4, new AxisAlignedBoundingBox(-9, -16, -29, 9, 19, 27)));
var bvhBuilder = new TradeOffBvhConstructor <int>();
var tree = bvhBuilder.CreateNewHierachy(data);
Assert.IsTrue(tree.CountBranches() == 1, "all the bounds overlap, there is no value in splitting them up");
var results = new List <int>();
tree.SearchBounds(new AxisAlignedBoundingBox(-9, -19, -29, 9, 19, 29), results);
Assert.AreEqual(results.Count(), 4, "Found all items.");
results.Clear();
tree.SearchPoint(0, 0, 0, results);
Assert.AreEqual(4, results.Count(), "All or around this point.");
}
public void MergeVertices(double treatAsSameDistance)
{
if (Vertices.Count < 2)
{
return;
}
var sameDistance = new Vector3Float(treatAsSameDistance, treatAsSameDistance, treatAsSameDistance);
var tinyDistance = new Vector3Float(.001, .001, .001);
// build a bvh tree of all the vertices
var bvhBuilder = new TradeOffBvhConstructor <int>();
var bvhTree = bvhBuilder.CreateNewHierachy(this.Vertices
.Select((v, i) => new BvhTreeItemData <int>(i, new AxisAlignedBoundingBox(v - tinyDistance, v + tinyDistance))).ToList());
var newVertices = new List <Vector3Float>(Vertices.Count);
var vertexIndexRemaping = Enumerable.Range(0, Vertices.Count).Select(i => - 1).ToList();
var searchResults = new List <int>();
// build up the list of index mapping
for (int i = 0; i < Vertices.Count; i++)
{
// first check if we have already found this vertex
if (vertexIndexRemaping[i] == -1)
{
var vertex = Vertices[i];
// remember the new index
var newIndex = newVertices.Count;
// add it to the vertices we will end up with
newVertices.Add(vertex);
// clear for new search
searchResults.Clear();
// find everything close
bvhTree.SearchBounds(new AxisAlignedBoundingBox(vertex - sameDistance, vertex + sameDistance), searchResults);
// map them to this new vertex
foreach (var result in searchResults)
{
// this vertex has not been mapped
if (vertexIndexRemaping[result] == -1)
{
vertexIndexRemaping[result] = newIndex;
}
}
}
}
// now make a new face list with the merge vertices
int GetIndex(int originalIndex)
{
return(vertexIndexRemaping[originalIndex]);
}
var newFaces = new FaceList();
foreach (var face in Faces)
{
int iv0 = GetIndex(face.v0);
int iv1 = GetIndex(face.v1);
int iv2 = GetIndex(face.v2);
if (iv0 != iv1 && iv1 != iv2 && iv2 != iv0)
{
newFaces.Add(iv0, iv1, iv2, newVertices);
}
}
this.Faces = newFaces;
this.Vertices = newVertices;
}
public void TestBvhAlongRay()
{
// for this shape imagine the 8 corners of a Rubik's cube and the center
var data = new List <BvhTreeItemData <int> >();
// left, front, bottom
data.Add(new BvhTreeItemData <int>(0, new AxisAlignedBoundingBox(0, 0, 0, 1, 1, 1)));
// right, front, bottom
data.Add(new BvhTreeItemData <int>(1, new AxisAlignedBoundingBox(2, 0, 0, 3, 1, 1)));
// left, back, bottom
data.Add(new BvhTreeItemData <int>(2, new AxisAlignedBoundingBox(0, 2, 0, 1, 3, 1)));
// right, back, bottom
data.Add(new BvhTreeItemData <int>(3, new AxisAlignedBoundingBox(2, 2, 0, 3, 3, 1)));
// center, center, center
data.Add(new BvhTreeItemData <int>(4, new AxisAlignedBoundingBox(1, 1, 1, 2, 2, 2)));
// left, front, top
data.Add(new BvhTreeItemData <int>(5, new AxisAlignedBoundingBox(0, 0, 2, 1, 1, 3)));
// right, front, top
data.Add(new BvhTreeItemData <int>(6, new AxisAlignedBoundingBox(2, 0, 2, 3, 1, 3)));
// left, back, top
data.Add(new BvhTreeItemData <int>(7, new AxisAlignedBoundingBox(0, 2, 2, 1, 3, 3)));
// right, back, top
data.Add(new BvhTreeItemData <int>(8, new AxisAlignedBoundingBox(2, 2, 2, 3, 3, 3)));
var bvhBuilder = new TradeOffBvhConstructor <int>();
var tree = bvhBuilder.CreateNewHierachy(data);
Assert.AreEqual(7, tree.CountBranches(), "these must be split up into multiple bounds");
var results = new List <int>();
tree.AlongRay(new Ray(new Vector3(-.5, .5, .5), Vector3.UnitX), results);
Assert.AreEqual(results.Count(), 2, "Found all items.");
Assert.IsTrue(results.Contains(0), "found the front left point.");
Assert.IsTrue(results.Contains(1), "found the front right point.");
results.Clear();
tree.AlongRay(new Ray(new Vector3(-.5, 1.5, 1.5), -Vector3.UnitX), results);
Assert.AreEqual(results.Count(), 0, "Found no items.");
results.Clear();
tree.AlongRay(new Ray(new Vector3(-.5, 1.5, 1.5), Vector3.UnitX), results);
Assert.AreEqual(results.Count(), 1, "Found only center.");
Assert.IsTrue(results.Contains(4), "found the center point.");
results.Clear();
tree.AlongRay(new Ray(new Vector3(-.5, -.5, -.5), new Vector3(1, 1, 1).GetNormal()), results);
Assert.AreEqual(results.Count(), 3, "Found all items.");
Assert.IsTrue(results.Contains(0), "found the left front bottom.");
Assert.IsTrue(results.Contains(4), "found the center.");
Assert.IsTrue(results.Contains(8), "found the right back top.");
results.Clear();
var shortRay = new Ray(new Vector3(-.5, -.5, -.5), new Vector3(1, 1, 1).GetNormal())
{
maxDistanceToConsider = 1
};
tree.AlongRay(shortRay, results);
Assert.AreEqual(results.Count(), 1, "Found all items.");
Assert.IsTrue(results.Contains(0), "found the left front bottom.");
}
