// Creates a clone of the mesh
#region Clone
public CSGMesh Clone()
{
var newPlanes = new Plane[Planes.Length];
for (int i = 0; i < Planes.Length; i++)
{
var plane = Planes[i];
newPlanes[i] = new Plane(plane.A, plane.B, plane.C, plane.D);
}
var newPolygons = new List <Polygon>(Polygons.Count);
foreach (var polygon in Polygons)
{
var newPolygon = new Polygon();
newPolygon.FirstIndex = polygon.FirstIndex;
newPolygon.Visible = polygon.Visible;
newPolygon.Category = polygon.Category;
newPolygon.PlaneIndex = polygon.PlaneIndex;
newPolygon.Bounds.Set(polygon.Bounds);
newPolygons.Add(newPolygon);
}
var newEdges = new List <HalfEdge>(Edges.Count);
foreach (var edge in Edges)
{
var newEdge = new HalfEdge();
newEdge.NextIndex = edge.NextIndex;
newEdge.PolygonIndex = edge.PolygonIndex;
newEdge.TwinIndex = edge.TwinIndex;
newEdge.VertexIndex = edge.VertexIndex;
newEdges.Add(newEdge);
}
var newVertices = new List <Vector3>(Vertices.Count);
foreach (var vertex in Vertices)
{
var newVertex = new Vector3();
newVertex.X = vertex.X;
newVertex.Y = vertex.Y;
newVertex.Z = vertex.Z;
newVertices.Add(newVertex);
}
var newBounds = new AABB(Bounds);
var newMesh = new CSGMesh(
newPlanes,
newPolygons,
newEdges,
newVertices,
newBounds);
return(newMesh);
}
public static ConcurrentDictionary <CSGNode, CSGMesh> ProcessCSGNodes(CSGNode root, IEnumerable <CSGNode> nodes)
{
var meshes = new ConcurrentDictionary <CSGNode, CSGMesh>();
var buildMesh =
(Action <CSGNode>)
delegate(CSGNode node)
{
CSGMesh mesh;
if (!cachedBaseMeshes.TryGetValue(node, out mesh))
{
// If the node we're performing csg on is a brush, we simply create the geometry from the planes
// If the node is a more complicated node, we perform csg on it's child nodes and combine the
// meshes that are created.
// Note that right now we cache brushes per node, but we can improve on this by caching on
// node type instead. Since lots of nodes will have the same geometry in real life and only
// need to be created once. It won't help much in runtime performance considering they're
// cached anyway, but it'll save on memory usage.
if (node.NodeType != CSGNodeType.Brush)
{
var childNodes = CSGUtility.FindChildBrushes(node);
var brushMeshes = ProcessCSGNodes(node, childNodes);
mesh = CSGMesh.Combine(node.Translation, brushMeshes);
}
else
{
mesh = CSGMesh.CreateFromPlanes(node.Planes);
}
// Cache the mesh
cachedBaseMeshes[node] = mesh;
}
// Clone the cached mesh so we can perform CSG on it.
var clonedMesh = mesh.Clone();
node.Bounds.Set(clonedMesh.Bounds);
meshes[node] = clonedMesh;
};
var updateDelegate =
(Action <KeyValuePair <CSGNode, CSGMesh> >)
delegate(KeyValuePair <CSGNode, CSGMesh> item)
{
var processedNode = item.Key;
var processedMesh = item.Value;
var inputPolygons = processedMesh.Polygons;
var insidePolygons = new List <Polygon>(inputPolygons.Count);
var outsidePolygons = new List <Polygon>(inputPolygons.Count);
var alignedPolygons = new List <Polygon>(inputPolygons.Count);
var reversedPolygons = new List <Polygon>(inputPolygons.Count);
CSGCategorization.Categorize(processedNode,
processedMesh,
root,
inputPolygons, // these are the polygons that are categorized
insidePolygons,
alignedPolygons,
reversedPolygons,
outsidePolygons
);
// Flag all non aligned polygons as being invisible, and store their categorizations
// so we can use it if we instance this mesh.
foreach (var polygon in insidePolygons)
{
polygon.Category = PolygonCategory.Inside;
polygon.Visible = false;
}
foreach (var polygon in outsidePolygons)
{
polygon.Category = PolygonCategory.Outside;
polygon.Visible = false;
}
foreach (var polygon in alignedPolygons)
{
polygon.Category = PolygonCategory.Aligned;
}
foreach (var polygon in reversedPolygons)
{
polygon.Category = PolygonCategory.ReverseAligned;
}
};
//
// Here we run build the meshes and perform csg on them either in serial or parallel
//
/*
* foreach (var node in nodes)
* buildMesh(node);
* CSGUtility.UpdateBounds(root);
* foreach (var item in meshes)
* updateDelegate(item);
* /*/
Parallel.ForEach(nodes, buildMesh);
CSGUtility.UpdateBounds(root);
Parallel.ForEach(meshes, updateDelegate);
//*/
return(meshes);
}
// Logical OR set operation on polygons
//
// Table showing final output from combination of categorization of left and right node
//
// | right node
// | inside aligned r-aligned outside
// -----------------+------------------------------------------
// left inside | I I I I
// node aligned | I A I A
// r-aligned | I I R R
// outside | I A R O
//
// I = inside A = aligned
// O = outside R = reverse aligned
//
#region LogicalOr
static void LogicalOr(CSGNode processedNode,
CSGMesh processedMesh,
CSGNode categorizationNode,
List <Polygon> inputPolygons,
List <Polygon> inside,
List <Polygon> aligned,
List <Polygon> revAligned,
List <Polygon> outside,
bool inverseLeft,
bool inverseRight)
{
var leftNode = categorizationNode.Left;
var rightNode = categorizationNode.Right;
var defaultCapacity = inputPolygons.Count / 2;
// ... Allocations are ridiculously cheap in .NET, there is a garbage collection penalty however.
// CSG can be performed without temporary buffers and recursion by using flags,
// which would increase performance and scalability (garbage collection interfers with parallelization).
// It makes the code a lot harder to read however.
var leftAligned = new List <Polygon>(defaultCapacity);
var leftRevAligned = new List <Polygon>(defaultCapacity);
var leftOutside = new List <Polygon>(defaultCapacity);
//var leftInside = new List<Polygon>(defaultCapacity); // everything that's inside the left node
// is always part of the inside category
// First categorize polygons in left path ...
if (inverseLeft)
{
Categorize(processedNode, processedMesh, leftNode,
inputPolygons,
leftOutside, leftRevAligned, leftAligned, inside);
}
else
{
Categorize(processedNode, processedMesh, leftNode,
inputPolygons,
inside, leftAligned, leftRevAligned, leftOutside);
}
// ... Then categorize the polygons in the right path
// Note that no single polygon will go into more than one of the Categorize methods below
if (inverseRight)
{
if (leftAligned.Count > 0)
{
if (inside == aligned)
{
inside.AddRange(leftAligned);
}
else
{
Categorize(processedNode, processedMesh, rightNode,
leftAligned,
aligned, inside, aligned, inside);
}
}
if (leftRevAligned.Count > 0)
{
if (inside == revAligned)
{
inside.AddRange(leftRevAligned);
}
else
{
Categorize(processedNode, processedMesh, rightNode,
leftRevAligned,
revAligned, revAligned, inside, inside);
}
}
if (leftOutside.Count > 0)
{
Categorize(processedNode, processedMesh, rightNode,
leftOutside,
outside, revAligned, aligned, inside);
}
}
else
{
if (leftAligned.Count > 0)
{
if (inside == aligned)
{
inside.AddRange(leftAligned);
}
else
{
Categorize(processedNode, processedMesh, rightNode,
leftAligned,
inside, aligned, inside, aligned);
}
}
if (leftRevAligned.Count > 0)
{
if (inside == revAligned)
{
inside.AddRange(leftRevAligned);
}
else
{
Categorize(processedNode, processedMesh, rightNode,
leftRevAligned,
inside, inside, revAligned, revAligned);
}
}
if (leftOutside.Count > 0)
{
Categorize(processedNode, processedMesh, rightNode,
leftOutside,
inside, aligned, revAligned, outside);
}
}
}
// Categorize the given inputPolygons as being inside/outside or (reverse-)aligned
// with the shape that is defined by the current brush or csg-branch.
// When an inputPolygon crosses the node, it is split into pieces and every individual
// piece is then categorized.
#region Categorize
public static void Categorize(CSGNode processedNode,
CSGMesh processedMesh,
CSGNode categorizationNode,
List <Polygon> inputPolygons,
List <Polygon> inside,
List <Polygon> aligned,
List <Polygon> revAligned,
List <Polygon> outside)
{
// When you go deep enough in the tree it's possible that all categories point to the same
// destination. So we detect that and potentially avoid a lot of wasted work.
if (inside == revAligned &&
inside == aligned &&
inside == outside)
{
inside.AddRange(inputPolygons);
return;
}
Restart:
if (processedNode == categorizationNode)
{
// When the currently processed node is the same node as we categorize against, then
// we know that all our polygons are visible and we set their default category
// (usually aligned, unless it's an instancing node in which case it's precalculated)
foreach (var polygon in inputPolygons)
{
switch (polygon.Category)
{
case PolygonCategory.Aligned: aligned.Add(polygon); break;
case PolygonCategory.ReverseAligned: revAligned.Add(polygon); break;
case PolygonCategory.Inside: inside.Add(polygon); break;
case PolygonCategory.Outside: outside.Add(polygon); break;
}
// When brushes overlap and they share the same surface area we only want to keep
// the polygons of the last brush in the tree, and skip all others.
// At this point in the tree we know that this polygon belongs to this brush, so
// we set it to visible. If the polygon is found to share the surface area with another
// brush further on in the tree it'll be set to invisible again in mesh.Intersect.
polygon.Visible = true;
}
return;
}
var leftNode = categorizationNode.Left;
var rightNode = categorizationNode.Right;
switch (categorizationNode.NodeType)
{
case CSGNodeType.Brush:
{
processedMesh.Intersect(categorizationNode.Bounds,
categorizationNode.Planes,
categorizationNode.Translation,
processedNode.Translation,
inputPolygons,
inside, aligned, revAligned, outside);
break;
}
case CSGNodeType.Addition:
{
// ( A || B)
var relativeLeftTrans = Vector3.Subtract(processedNode.Translation, leftNode.Translation);
var relativeRightTrans = Vector3.Subtract(processedNode.Translation, rightNode.Translation);
if (AABB.IsOutside(processedNode.Bounds, relativeLeftTrans, leftNode.Bounds))
{
if (AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
// When our polygons lie outside the bounds of both the left and the right node, then
// all the polygons can be categorized as being 'outside'
outside.AddRange(inputPolygons);
}
else
{
//Categorize(processedNode, mesh, right,
// inputPolygons,
// inside, aligned, revAligned, outside);
categorizationNode = rightNode;
goto Restart;
}
}
else
if (AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
//Categorize(processedNode, left, mesh,
// inputPolygons,
// inside, aligned, revAligned, outside);
categorizationNode = leftNode;
goto Restart;
}
else
{
LogicalOr(processedNode, processedMesh, categorizationNode,
inputPolygons,
inside, aligned, revAligned, outside,
false, false);
}
break;
}
case CSGNodeType.Common:
{
// !(!A || !B)
var relativeLeftTrans = Vector3.Subtract(processedNode.Translation, leftNode.Translation);
var relativeRightTrans = Vector3.Subtract(processedNode.Translation, rightNode.Translation);
if (AABB.IsOutside(processedNode.Bounds, relativeLeftTrans, leftNode.Bounds) ||
AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
// When our polygons lie outside the bounds of both the left and the right node, then
// all the polygons can be categorized as being 'outside'
outside.AddRange(inputPolygons);
}
else
{
LogicalOr(processedNode, processedMesh, categorizationNode,
inputPolygons,
outside, revAligned, aligned, inside,
true, true);
}
break;
}
case CSGNodeType.Subtraction:
{
// !(!A || B)
var relativeLeftTrans = Vector3.Subtract(processedNode.Translation, leftNode.Translation);
var relativeRightTrans = Vector3.Subtract(processedNode.Translation, rightNode.Translation);
if (AABB.IsOutside(processedNode.Bounds, relativeLeftTrans, leftNode.Bounds))
{
// When our polygons lie outside the bounds of both the left node, then
// all the polygons can be categorized as being 'outside'
outside.AddRange(inputPolygons);
}
else
if (AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
categorizationNode = leftNode;
goto Restart;
}
else
{
LogicalOr(processedNode, processedMesh, categorizationNode,
inputPolygons,
outside, revAligned, aligned, inside,
true, false);
}
break;
}
}
}
public CSGMesh Clone()
{
var newPlanes = new Plane[Planes.Length];
for (int i = 0; i < Planes.Length; i++)
{
var plane = Planes[i];
newPlanes[i] = new Plane(plane.A, plane.B, plane.C, plane.D);
}
var newPolygons = new List<Polygon>(Polygons.Count);
foreach (var polygon in Polygons)
{
var newPolygon = new Polygon();
newPolygon.FirstIndex = polygon.FirstIndex;
newPolygon.Visible = polygon.Visible;
newPolygon.Category = polygon.Category;
newPolygon.PlaneIndex = polygon.PlaneIndex;
newPolygon.Bounds.Set(polygon.Bounds);
newPolygons.Add(newPolygon);
}
var newEdges = new List<HalfEdge>(Edges.Count);
foreach (var edge in Edges)
{
var newEdge = new HalfEdge();
newEdge.NextIndex = edge.NextIndex;
newEdge.PolygonIndex = edge.PolygonIndex;
newEdge.TwinIndex = edge.TwinIndex;
newEdge.VertexIndex = edge.VertexIndex;
newEdges.Add(newEdge);
}
var newVertices = new List<Vector3>(Vertices.Count);
foreach (var vertex in Vertices)
{
var newVertex = new Vector3();
newVertex.X = vertex.X;
newVertex.Y = vertex.Y;
newVertex.Z = vertex.Z;
newVertices.Add(newVertex);
}
var newBounds = new AABB(Bounds);
var newMesh = new CSGMesh(
newPlanes,
newPolygons,
newEdges,
newVertices,
newBounds);
return newMesh;
}
static void LogicalOr( CSGNode processedNode,
CSGMesh processedMesh,
CSGNode categorizationNode,
List<Polygon> inputPolygons,
List<Polygon> inside,
List<Polygon> aligned,
List<Polygon> revAligned,
List<Polygon> outside,
bool inverseLeft,
bool inverseRight)
{
var leftNode = categorizationNode.Left;
var rightNode = categorizationNode.Right;
var defaultCapacity = inputPolygons.Count / 2;
// ... Allocations are ridiculously cheap in .NET, there is a garbage collection penalty however.
// CSG can be performed without temporary buffers and recursion by using flags,
// which would increase performance and scalability (garbage collection interfers with parallelization).
// It makes the code a lot harder to read however.
var leftAligned = new List<Polygon>(defaultCapacity);
var leftRevAligned = new List<Polygon>(defaultCapacity);
var leftOutside = new List<Polygon>(defaultCapacity);
//var leftInside = new List<Polygon>(defaultCapacity); // everything that's inside the left node
// is always part of the inside category
// First categorize polygons in left path ...
if (inverseLeft)
Categorize(processedNode, processedMesh, leftNode,
inputPolygons,
leftOutside, leftRevAligned, leftAligned, inside);
else
Categorize(processedNode, processedMesh, leftNode,
inputPolygons,
inside, leftAligned, leftRevAligned, leftOutside);
// ... Then categorize the polygons in the right path
// Note that no single polygon will go into more than one of the Categorize methods below
if (inverseRight)
{
if (leftAligned.Count > 0)
{
if (inside == aligned)
{
inside.AddRange(leftAligned);
} else
Categorize(processedNode, processedMesh, rightNode,
leftAligned,
aligned, inside, aligned, inside);
}
if (leftRevAligned.Count > 0)
{
if (inside == revAligned)
{
inside.AddRange(leftRevAligned);
} else
Categorize(processedNode, processedMesh, rightNode,
leftRevAligned,
revAligned, revAligned, inside, inside);
}
if (leftOutside.Count > 0)
{
Categorize(processedNode, processedMesh, rightNode,
leftOutside,
outside, revAligned, aligned, inside);
}
} else
{
if (leftAligned.Count > 0)
{
if (inside == aligned)
{
inside.AddRange(leftAligned);
} else
Categorize(processedNode, processedMesh, rightNode,
leftAligned,
inside, aligned, inside, aligned);
}
if (leftRevAligned.Count > 0)
{
if (inside == revAligned)
{
inside.AddRange(leftRevAligned);
} else
Categorize(processedNode, processedMesh, rightNode,
leftRevAligned,
inside, inside, revAligned, revAligned);
}
if (leftOutside.Count > 0)
{
Categorize(processedNode, processedMesh, rightNode,
leftOutside,
inside, aligned, revAligned, outside);
}
}
}
public static void Categorize(CSGNode processedNode,
CSGMesh processedMesh,
CSGNode categorizationNode,
List<Polygon> inputPolygons,
List<Polygon> inside,
List<Polygon> aligned,
List<Polygon> revAligned,
List<Polygon> outside)
{
// When you go deep enough in the tree it's possible that all categories point to the same
// destination. So we detect that and potentially avoid a lot of wasted work.
if (inside == revAligned &&
inside == aligned &&
inside == outside)
{
inside.AddRange(inputPolygons);
return;
}
Restart:
if (processedNode == categorizationNode)
{
// When the currently processed node is the same node as we categorize against, then
// we know that all our polygons are visible and we set their default category
// (usually aligned, unless it's an instancing node in which case it's precalculated)
foreach (var polygon in inputPolygons)
{
switch (polygon.Category)
{
case PolygonCategory.Aligned: aligned.Add(polygon); break;
case PolygonCategory.ReverseAligned: revAligned.Add(polygon); break;
case PolygonCategory.Inside: inside.Add(polygon); break;
case PolygonCategory.Outside: outside.Add(polygon); break;
}
// When brushes overlap and they share the same surface area we only want to keep
// the polygons of the last brush in the tree, and skip all others.
// At this point in the tree we know that this polygon belongs to this brush, so
// we set it to visible. If the polygon is found to share the surface area with another
// brush further on in the tree it'll be set to invisible again in mesh.Intersect.
polygon.Visible = true;
}
return;
}
var leftNode = categorizationNode.Left;
var rightNode = categorizationNode.Right;
switch (categorizationNode.NodeType)
{
case CSGNodeType.Brush:
{
processedMesh.Intersect( categorizationNode.Bounds,
categorizationNode.Planes,
categorizationNode.Translation,
processedNode.Translation,
inputPolygons,
inside, aligned, revAligned, outside);
break;
}
case CSGNodeType.Addition:
{
// ( A || B)
var relativeLeftTrans = Vector3.Subtract(processedNode.Translation, leftNode.Translation);
var relativeRightTrans = Vector3.Subtract(processedNode.Translation, rightNode.Translation);
if (AABB.IsOutside(processedNode.Bounds, relativeLeftTrans, leftNode.Bounds))
{
if (AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
// When our polygons lie outside the bounds of both the left and the right node, then
// all the polygons can be categorized as being 'outside'
outside.AddRange(inputPolygons);
} else
{
//Categorize(processedNode, mesh, right,
// inputPolygons,
// inside, aligned, revAligned, outside);
categorizationNode = rightNode;
goto Restart;
}
} else
if (AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
//Categorize(processedNode, left, mesh,
// inputPolygons,
// inside, aligned, revAligned, outside);
categorizationNode = leftNode;
goto Restart;
} else
{
LogicalOr(processedNode, processedMesh, categorizationNode,
inputPolygons,
inside, aligned, revAligned, outside,
false, false);
}
break;
}
case CSGNodeType.Common:
{
// !(!A || !B)
var relativeLeftTrans = Vector3.Subtract(processedNode.Translation, leftNode.Translation);
var relativeRightTrans = Vector3.Subtract(processedNode.Translation, rightNode.Translation);
if (AABB.IsOutside(processedNode.Bounds, relativeLeftTrans, leftNode.Bounds) ||
AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
// When our polygons lie outside the bounds of both the left and the right node, then
// all the polygons can be categorized as being 'outside'
outside.AddRange(inputPolygons);
} else
{
LogicalOr(processedNode, processedMesh, categorizationNode,
inputPolygons,
outside, revAligned, aligned, inside,
true, true);
}
break;
}
case CSGNodeType.Subtraction:
{
// !(!A || B)
var relativeLeftTrans = Vector3.Subtract(processedNode.Translation, leftNode.Translation);
var relativeRightTrans = Vector3.Subtract(processedNode.Translation, rightNode.Translation);
if (AABB.IsOutside(processedNode.Bounds, relativeLeftTrans, leftNode.Bounds))
{
// When our polygons lie outside the bounds of both the left node, then
// all the polygons can be categorized as being 'outside'
outside.AddRange(inputPolygons);
} else
if (AABB.IsOutside(processedNode.Bounds, relativeRightTrans, rightNode.Bounds))
{
categorizationNode = leftNode;
goto Restart;
} else
{
LogicalOr(processedNode, processedMesh, categorizationNode,
inputPolygons,
outside, revAligned, aligned, inside,
true, false);
}
break;
}
}
}
