private void CreateScene()
{
scene = new Scene();
scene.camera = new TrackBallCamera(trackballTumbleWidget);
scene.background = new Background(new RGBA_Floats(0.5, .5, .5), 0.4);
AddBoxAndSheresBooleanTest();
//AddBoxAndBoxBooleanTest();
#if false
renderCollection.Add(new BoxShape(new Vector3(), new Vector3(1, 1, 1),
new SolidMaterial(new RGBA_Floats(.9, .2, .1), .01, 0.0, 2.0)));
renderCollection.Add(new BoxShape(new Vector3(.5, .5, .5), new Vector3(1.5, 1.5, 1.5),
new SolidMaterial(new RGBA_Floats(.9, .2, .1), .01, 0.0, 2.0)));
#endif
//renderCollection.Add(new CylinderShape(.25, 1, new SolidMaterial(RGBA_Floats.Cyan, 0, 0, 0)));
//AddTestStl();
//AddPolygonTest();
//AddSphereAndBox();
//AddAxisMarker();
//AddCubeOfShperes();
//renderCollection.Add(MakerGearXCariage());
allObjects = BoundingVolumeHierarchy.CreateNewHierachy(renderCollection);
allObjectsHolder = new Transform(allObjects);
//allObjects = root;
scene.shapes.Add(allObjectsHolder);
//AddAFloor();
//add two lights for better lighting effects
scene.lights.Add(new PointLight(new Vector3(5000, 5000, 5000), new RGBA_Floats(0.8, 0.8, 0.8)));
scene.lights.Add(new PointLight(new Vector3(-5000, -5000, 3000), new RGBA_Floats(0.5, 0.5, 0.5)));
}
/// <summary>
/// This will remove the shapes from 'Shapes' and add them to a Bounding Volume Hierarchy. Then add that at a single element
/// to 'Shapes'. You could also create a list of 'List<IPrimitive>' and put that directly into a BVH and then add that
/// to the Shapes list (there could be more than 1 BVH in the 'Shapes' list.
/// </summary>
public ITraceable MoveShapesIntoBoundingVolumeHierachy()
{
var rootObject = BoundingVolumeHierarchy.CreateNewHierachy(shapes);
if (rootObject != null)
{
shapes.Clear();
shapes.Add(rootObject);
}
return(rootObject);
}
private void AddBoxAndBoxBooleanTest()
{
BoxShape box1 = new BoxShape(new Vector3(.5, .5, .5), new Vector3(1.5, 1.5, 1.5),
new SolidMaterial(RGBA_Floats.Green, .01, 0.0, 2.0));
List <IPrimitive> subtractShapes = new List <IPrimitive>();
SolidMaterial material = new SolidMaterial(RGBA_Floats.Red, 0, 0, 0);
subtractShapes.Add(new BoxShape(new Vector3(), new Vector3(1, 1, 1), material));
IPrimitive subtractGroup = BoundingVolumeHierarchy.CreateNewHierachy(subtractShapes);
Difference merge = new Difference(box1, subtractGroup);
renderCollection.Add(merge);
}
private void AddCubeOfShperes()
{
List <IPrimitive> scanData1 = new List <IPrimitive>();
Random rand = new Random(0);
double dist = 2;
for (int i = 0; i < 4000; i++)
{
BaseShape littleShpere = new SphereShape(new Vector3(rand.NextDouble() * dist - dist / 2, rand.NextDouble() * dist - dist / 2, rand.NextDouble() * dist - dist / 2),
rand.NextDouble() * .1 + .01,
new SolidMaterial(new RGBA_Floats(rand.NextDouble() * .5 + .5, rand.NextDouble() * .5 + .5, rand.NextDouble() * .5 + .5), 0, 0.0, 2.0));
scanData1.Add(littleShpere);
}
renderCollection.Add(BoundingVolumeHierarchy.CreateNewHierachy(scanData1));
}
private void CreateScene()
{
scene = new Scene();
scene.camera = new TrackBallCamera(trackballTumbleWidget);
//scene.background = new Background(new RGBA_Floats(0.5, .5, .5), 0.4);
scene.background = new Background(new RGBA_Floats(1, 1, 1, 0), 0.6);
AddTestMesh(loadedMeshGroups);
allObjects = BoundingVolumeHierarchy.CreateNewHierachy(renderCollection);
allObjectsHolder = new Transform(allObjects);
//allObjects = root;
scene.shapes.Add(allObjectsHolder);
//AddAFloor();
//add two lights for better lighting effects
//scene.lights.Add(new Light(new Vector3(5000, 5000, 5000), new RGBA_Floats(0.8, 0.8, 0.8)));
scene.lights.Add(new PointLight(new Vector3(-5000, -5000, 3000), new RGBA_Floats(0.5, 0.5, 0.5)));
}
private void AddBoxAndSheresBooleanTest()
{
BoxShape box1 = new BoxShape(new Vector3(.5, .5, .5), new Vector3(1.5, 1.5, 1.5),
new SolidMaterial(RGBA_Floats.Green, 0, 0, 0));//.01, 0.0, 2.0));
List <IRayTraceable> subtractShapes = new List <IRayTraceable>();
SolidMaterial material = new SolidMaterial(RGBA_Floats.Red, 0, 0, 0);
#if true
// two big spheres. Looks good.
subtractShapes.Add(new SphereShape(new Vector3(.5, .5, 1), .6, material));
subtractShapes.Add(new SphereShape(new Vector3(1.5, .5, 1), .6, material));
Transform cylinder = new Transform(new CylinderShape(.1, 3, material));
cylinder.MoveToAbsolute(1, 1, 1);
cylinder.RotateRelative(.1, .6, .6);
//subtractShapes.Add(cylinder);
//renderCollection.Add(cylinder);
#else
for (int z = 0; z < 6; z++)
{
for (int y = 0; y < 6; y++)
{
for (int x = 0; x < 6; x++)
{
subtractShapes.Add(new SphereShape(new Vector3(x * .2 + .5, y * .2 + .5, z * .2 + .5), .1, material));
//subtractShapes.Add(new SphereShape(new Vector3(x * .2 + .5, y * .2 + .5, z * .2 + .5), .13, material));
}
}
}
#endif
IRayTraceable subtractGroup = BoundingVolumeHierarchy.CreateNewHierachy(subtractShapes);
Difference merge = new Difference(box1, subtractGroup);
renderCollection.Add(merge);
}
private void CreateScene()
{
scene = new Scene();
scene.camera = new Camera((int)Width, (int)Height, MathHelper.DegreesToRadians(40));
scene.background = new Background(new RGBA_Floats(0.5, .5, .5), 0.4);
//AddBoxAndSheresBooleanTest();
//AddBoxAndBoxBooleanTest();
#if false
renderCollection.Add(new BoxShape(new Vector3(), new Vector3(1, 1, 1),
new SolidMaterial(new RGBA_Floats(.9, .2, .1), .01, 0.0, 2.0)));
renderCollection.Add(new BoxShape(new Vector3(.5, .5, .5), new Vector3(1.5, 1.5, 1.5),
new SolidMaterial(new RGBA_Floats(.9, .2, .1), .01, 0.0, 2.0)));
#endif
//renderCollection.Add(new CylinderShape(.25, 1, new SolidMaterial(RGBA_Floats.Cyan, 0, 0, 0)));
AddTestStl();
//AddPolygonTest();
//AddSphereAndBox();
//AddAxisMarker();
//AddCubeOfShperes();
//renderCollection.Add(MakerGearXCariage());
allObjects = BoundingVolumeHierarchy.CreateNewHierachy(renderCollection);
trackBallTransform = new Transform(allObjects);
//allObjects = root;
scene.shapes.Add(trackBallTransform);
//AddAFloor();
//add two lights for better lighting effects
scene.lights.Add(new Light(new Vector3(50, 10, 100), new RGBA_Floats(0.8, 0.8, 0.8)));
scene.lights.Add(new Light(new Vector3(-30, 150, 50), new RGBA_Floats(0.8, 0.8, 0.8)));
OrientCamera();
}
public static IPrimitive CreateNewHierachy(List <IPrimitive> traceableItems, int maxRecursion = int.MaxValue, int recursionDepth = 0, SortingAccelerator accelerator = null)
{
if (accelerator == null)
{
accelerator = new SortingAccelerator();
}
int numItems = traceableItems.Count;
if (numItems == 0)
{
return(null);
}
if (numItems == 1)
{
return(traceableItems[0]);
}
int bestAxis = -1;
int bestIndexToSplitOn = -1;
var axisSorter = new CompareCentersOnAxis(0);
if (recursionDepth < maxRecursion)
{
if (numItems > 50)
{
bestAxis = accelerator.NextAxis;
bestIndexToSplitOn = numItems / 2;
}
else
{
double totalIntersectCost = 0;
int skipInterval = 1;
for (int i = 0; i < numItems; i += skipInterval)
{
IPrimitive item = traceableItems[i];
totalIntersectCost += item.GetIntersectCost();
}
// get the bounding box of all the items we are going to consider.
AxisAlignedBoundingBox OverallBox = traceableItems[0].GetAxisAlignedBoundingBox();
for (int i = skipInterval; i < numItems; i += skipInterval)
{
OverallBox += traceableItems[i].GetAxisAlignedBoundingBox();
}
double areaOfTotalBounds = OverallBox.GetSurfaceArea();
double bestCost = totalIntersectCost;
var totalDeviationOnAxis = default(Vector3);
double[] surfaceArreaOfItem = new double[numItems - 1];
double[] rightBoundsAtItem = new double[numItems - 1];
for (int axis = 0; axis < 3; axis++)
{
double intersectCostOnLeft = 0;
axisSorter.WhichAxis = axis;
traceableItems.Sort(axisSorter);
// Get all left bounds
AxisAlignedBoundingBox currentLeftBounds = traceableItems[0].GetAxisAlignedBoundingBox();
surfaceArreaOfItem[0] = currentLeftBounds.GetSurfaceArea();
for (int itemIndex = 1; itemIndex < numItems - 1; itemIndex += skipInterval)
{
currentLeftBounds += traceableItems[itemIndex].GetAxisAlignedBoundingBox();
surfaceArreaOfItem[itemIndex] = currentLeftBounds.GetSurfaceArea();
totalDeviationOnAxis[axis] += Math.Abs(traceableItems[itemIndex].GetCenter()[axis] - traceableItems[itemIndex - 1].GetCenter()[axis]);
}
// Get all right bounds
if (numItems > 1)
{
AxisAlignedBoundingBox currentRightBounds = traceableItems[numItems - 1].GetAxisAlignedBoundingBox();
rightBoundsAtItem[numItems - 2] = currentRightBounds.GetSurfaceArea();
for (int itemIndex = numItems - 1; itemIndex > 1; itemIndex -= skipInterval)
{
currentRightBounds += traceableItems[itemIndex - 1].GetAxisAlignedBoundingBox();
rightBoundsAtItem[itemIndex - 2] = currentRightBounds.GetSurfaceArea();
}
}
// Sweep from left
for (int itemIndex = 0; itemIndex < numItems - 1; itemIndex += skipInterval)
{
double thisCost = 0;
{
// Evaluate Surface Cost Equation
double costOfTwoAABB = 2 * AxisAlignedBoundingBox.GetIntersectCost(); // the cost of the two children AABB tests
// do the left cost
intersectCostOnLeft += traceableItems[itemIndex].GetIntersectCost();
double leftCost = (surfaceArreaOfItem[itemIndex] / areaOfTotalBounds) * intersectCostOnLeft;
// do the right cost
double intersectCostOnRight = totalIntersectCost - intersectCostOnLeft;
double rightCost = (rightBoundsAtItem[itemIndex] / areaOfTotalBounds) * intersectCostOnRight;
thisCost = costOfTwoAABB + leftCost + rightCost;
}
if (thisCost < bestCost + .000000001) // if it is less within some tiny error
{
if (thisCost > bestCost - .000000001)
{
// they are the same within the error
if (axis > 0 && bestAxis != axis) // we have changed axis since last best and we need to decide if this is better than the last axis best
{
if (totalDeviationOnAxis[axis] > totalDeviationOnAxis[axis - 1])
{
// this new axis is better and we'll switch to it. Otherwise don't switch.
bestCost = thisCost;
bestIndexToSplitOn = itemIndex;
bestAxis = axis;
}
}
}
else // this is just better
{
bestCost = thisCost;
bestIndexToSplitOn = itemIndex;
bestAxis = axis;
}
}
}
}
}
}
if (bestAxis == -1)
{
// No better partition found
return(new UnboundCollection(traceableItems));
}
else
{
var leftItems = new List <IPrimitive>(bestIndexToSplitOn + 1);
var rightItems = new List <IPrimitive>(numItems - bestIndexToSplitOn + 1);
if (numItems > 100)
{
// there are lots of items, lets find a sampled bounds and then choose a center
var totalBounds = AxisAlignedBoundingBox.Empty();
for (int i = 0; i < 50; i++)
{
totalBounds.ExpandToInclude(traceableItems[i * numItems / 50].GetCenter());
}
bestAxis = totalBounds.XSize > totalBounds.YSize ? 0 : 1;
bestAxis = totalBounds.Size[bestAxis] > totalBounds.ZSize ? bestAxis : 2;
var axisCenter = totalBounds.Center[bestAxis];
for (int i = 0; i < numItems; i++)
{
if (traceableItems[i].GetAxisCenter(bestAxis) <= axisCenter)
{
leftItems.Add(traceableItems[i]);
}
else
{
rightItems.Add(traceableItems[i]);
}
}
}
else // sort them and find the center
{
axisSorter.WhichAxis = bestAxis;
traceableItems.Sort(axisSorter);
for (int i = 0; i <= bestIndexToSplitOn; i++)
{
leftItems.Add(traceableItems[i]);
}
for (int i = bestIndexToSplitOn + 1; i < numItems; i++)
{
rightItems.Add(traceableItems[i]);
}
}
IPrimitive leftGroup = CreateNewHierachy(leftItems, maxRecursion, recursionDepth + 1, accelerator);
IPrimitive rightGroup = CreateNewHierachy(rightItems, maxRecursion, recursionDepth + 1, accelerator);
var newBVHNode = new BoundingVolumeHierarchy(leftGroup, rightGroup, bestAxis);
return(newBVHNode);
}
}
public void DifferenceTestsForBox()
{
SolidMaterial redMaterial = new SolidMaterial(ColorF.Red, 0, 0, 0);
SolidMaterial blueMaterial = new SolidMaterial(ColorF.Blue, 0, 0, 0);
Ray castRay = new Ray(new Vector3(0, -1, 0), Vector3.UnitY);
BoxShape box1X1 = new BoxShape(new Vector3(-.5, -.5, -.5), new Vector3(.5, .5, .5), blueMaterial);
// just a box all by itself
{
IntersectInfo testInfo = box1X1.GetClosestIntersection(castRay);
Assert.IsTrue(testInfo.hitType == IntersectionType.FrontFace, "Found Hit : Box No CSG");
Assert.IsTrue(testInfo.closestHitObject == box1X1, "Found Hit : Box No CSG");
Assert.IsTrue(testInfo.HitPosition == new Vector3(0, -.5, 0), "Hit position y = -.5 : Box No CSG");
Assert.IsTrue(testInfo.distanceToHit == .5, "Hit length = .5 : Box No CSG");
Assert.IsTrue(testInfo.normalAtHit == -Vector3.UnitY, "Normal Correct : Box No CSG");
}
// one subtract from the front of a box, the front faces are aligned
{
BoxShape subtractBox = new BoxShape(new Vector3(-.5, -.5, -.5), new Vector3(.5, 0, .5), redMaterial);
Difference merge = new Difference(box1X1, subtractBox);
IntersectInfo testInfo = merge.GetClosestIntersection(castRay);
Assert.IsTrue(testInfo.hitType == IntersectionType.FrontFace, "Found Hit : One Subtract");
Assert.IsTrue(testInfo.closestHitObject == subtractBox, "Found Hit : One Subtract");
Assert.IsTrue(testInfo.HitPosition == new Vector3(0, 0, 0), "Hit position y = 0 : One Subtract");
Assert.IsTrue(testInfo.distanceToHit == 1, "Hit length = 1 : One Subtract");
Assert.IsTrue(testInfo.normalAtHit == -Vector3.UnitY, "Normal Correct : One Subtract");
}
#if false
// An internal primary object that needs to be skipped over
{
List <IPrimitive> primaryShapes = new List <IPrimitive>();
BoxShape insideBox = new BoxShape(new Vector3(-.1, -.1, -.1), new Vector3(.1, .1, .1), blueMaterial);
primaryShapes.Add(box1X1);
primaryShapes.Add(insideBox);
IPrimitive primamryGroup = BoundingVolumeHierarchy.CreateNewHierachy(primaryShapes);
List <IPrimitive> subtractShapes = new List <IPrimitive>();
subtractShapes.Add(new BoxShape(new Vector3(-.5, -.5, -.5), new Vector3(.5, .4, .5), redMaterial));
IPrimitive subtractGroup = BoundingVolumeHierarchy.CreateNewHierachy(subtractShapes);
Difference merge = new Difference(primamryGroup, subtractGroup);
IntersectInfo testInfo = merge.GetClosestIntersection(castRay);
Assert.IsTrue(testInfo.isHit == true, "Found Hit : 5 Subtracts");
//Assert.IsTrue(testInfo.closestHitObject == subtractBox, "Found Hit : 5 Subtracts");
Assert.IsTrue(testInfo.hitPosition == new Vector3(0, 0, 0), "Hit position y = 0 : 5 Subtracts");
Assert.IsTrue(testInfo.distanceToHit == 1, "Hit length = 1 : 5 Subtracts");
Assert.IsTrue(testInfo.normalAtHit == -Vector3.UnitY, "Normal Correct : 5 Subtracts");
}
// Go through 5 subtract boxes to get to 1/2 way through the main box.
{
List <IPrimitive> subtractShapes = new List <IPrimitive>();
for (int i = 0; i < 5; i++)
{
subtractShapes.Add(new BoxShape(new Vector3(-.5, -.5 + i * .1, -.5), new Vector3(.5, -.4 + i * .1, .5), redMaterial));
}
IPrimitive subtractGroup = BoundingVolumeHierarchy.CreateNewHierachy(subtractShapes);
Difference merge = new Difference(box1X1, subtractGroup);
IntersectInfo testInfo = merge.GetClosestIntersection(castRay);
Assert.IsTrue(testInfo.isHit == true, "Found Hit : 5 Subtracts");
//Assert.IsTrue(testInfo.closestHitObject == subtractBox, "Found Hit : 5 Subtracts");
Assert.IsTrue(testInfo.hitPosition == new Vector3(0, 0, 0), "Hit position y = 0 : 5 Subtracts");
Assert.IsTrue(testInfo.distanceToHit == 1, "Hit length = 1 : 5 Subtracts");
Assert.IsTrue(testInfo.normalAtHit == -Vector3.UnitY, "Normal Correct : 5 Subtracts");
}
#endif
}
public static IPrimitive CreateNewHierachy(List<IPrimitive> traceableItems, int maxRecursion = int.MaxValue, int recursionDepth = 0, SortingAccelerator accelerator = null)
{
if (accelerator == null)
{
accelerator = new SortingAccelerator();
}
int numItems = traceableItems.Count;
if (numItems == 0)
{
return null;
}
if (numItems == 1)
{
return traceableItems[0];
}
int bestAxis = -1;
int bestIndexToSplitOn = -1;
CompareCentersOnAxis axisSorter = new CompareCentersOnAxis(0);
if (recursionDepth < maxRecursion)
{
if (numItems > 5000)
{
bestAxis = accelerator.NextAxis;
bestIndexToSplitOn = numItems / 2;
}
else
{
double totalIntersectCost = 0;
int skipInterval = 1;
for (int i = 0; i < numItems; i += skipInterval)
{
IPrimitive item = traceableItems[i];
totalIntersectCost += item.GetIntersectCost();
}
// get the bounding box of all the items we are going to consider.
AxisAlignedBoundingBox OverallBox = traceableItems[0].GetAxisAlignedBoundingBox();
for (int i = skipInterval; i < numItems; i += skipInterval)
{
OverallBox += traceableItems[i].GetAxisAlignedBoundingBox();
}
double areaOfTotalBounds = OverallBox.GetSurfaceArea();
double bestCost = totalIntersectCost;
Vector3 totalDeviationOnAxis = new Vector3();
double[] surfaceArreaOfItem = new double[numItems - 1];
double[] rightBoundsAtItem = new double[numItems - 1];
for (int axis = 0; axis < 3; axis++)
{
double intersectCostOnLeft = 0;
axisSorter.WhichAxis = axis;
traceableItems.Sort(axisSorter);
// Get all left bounds
AxisAlignedBoundingBox currentLeftBounds = traceableItems[0].GetAxisAlignedBoundingBox();
surfaceArreaOfItem[0] = currentLeftBounds.GetSurfaceArea();
for (int itemIndex = 1; itemIndex < numItems - 1; itemIndex += skipInterval)
{
currentLeftBounds += traceableItems[itemIndex].GetAxisAlignedBoundingBox();
surfaceArreaOfItem[itemIndex] = currentLeftBounds.GetSurfaceArea();
totalDeviationOnAxis[axis] += Math.Abs(traceableItems[itemIndex].GetCenter()[axis] - traceableItems[itemIndex - 1].GetCenter()[axis]);
}
// Get all right bounds
if (numItems > 1)
{
AxisAlignedBoundingBox currentRightBounds = traceableItems[numItems - 1].GetAxisAlignedBoundingBox();
rightBoundsAtItem[numItems - 2] = currentRightBounds.GetSurfaceArea();
for (int itemIndex = numItems - 1; itemIndex > 1; itemIndex -= skipInterval)
{
currentRightBounds += traceableItems[itemIndex - 1].GetAxisAlignedBoundingBox();
rightBoundsAtItem[itemIndex - 2] = currentRightBounds.GetSurfaceArea();
}
}
// Sweep from left
for (int itemIndex = 0; itemIndex < numItems - 1; itemIndex += skipInterval)
{
double thisCost = 0;
{
// Evaluate Surface Cost Equation
double costOfTwoAABB = 2 * AxisAlignedBoundingBox.GetIntersectCost(); // the cost of the two children AABB tests
// do the left cost
intersectCostOnLeft += traceableItems[itemIndex].GetIntersectCost();
double leftCost = (surfaceArreaOfItem[itemIndex] / areaOfTotalBounds) * intersectCostOnLeft;
// do the right cost
double intersectCostOnRight = totalIntersectCost - intersectCostOnLeft;
double rightCost = (rightBoundsAtItem[itemIndex] / areaOfTotalBounds) * intersectCostOnRight;
thisCost = costOfTwoAABB + leftCost + rightCost;
}
if (thisCost < bestCost + .000000001) // if it is less within some tiny error
{
if (thisCost > bestCost - .000000001)
{
// they are the same within the error
if (axis > 0 && bestAxis != axis) // we have changed axis since last best and we need to decide if this is better than the last axis best
{
if (totalDeviationOnAxis[axis] > totalDeviationOnAxis[axis - 1])
{
// this new axis is better and we'll switch to it. Otherwise don't switch.
bestCost = thisCost;
bestIndexToSplitOn = itemIndex;
bestAxis = axis;
}
}
}
else // this is just better
{
bestCost = thisCost;
bestIndexToSplitOn = itemIndex;
bestAxis = axis;
}
}
}
}
}
}
if (bestAxis == -1)
{
// No better partition found
return new UnboundCollection(traceableItems);
}
else
{
axisSorter.WhichAxis = bestAxis;
traceableItems.Sort(axisSorter);
List<IPrimitive> leftItems = new List<IPrimitive>(bestIndexToSplitOn + 1);
List<IPrimitive> rightItems = new List<IPrimitive>(numItems - bestIndexToSplitOn + 1);
for (int i = 0; i <= bestIndexToSplitOn; i++)
{
leftItems.Add(traceableItems[i]);
}
for (int i = bestIndexToSplitOn + 1; i < numItems; i++)
{
rightItems.Add(traceableItems[i]);
}
IPrimitive leftGroup = CreateNewHierachy(leftItems, maxRecursion, recursionDepth + 1, accelerator);
IPrimitive rightGroup = CreateNewHierachy(rightItems, maxRecursion, recursionDepth + 1, accelerator);
BoundingVolumeHierarchy newBVHNode = new BoundingVolumeHierarchy(leftGroup, rightGroup, bestAxis);
return newBVHNode;
}
}
