/// <summary>
/// Generates triangles for an infinite plane that will completely intersect the given bounding box
/// </summary>
private NavigationMeshInputBuilder BuildPlaneGeometry(Plane plane, BoundingBox boundingBox)
{
Vector3 maxSize = boundingBox.Maximum - boundingBox.Minimum;
float maxDiagonal = Math.Max(maxSize.X, Math.Max(maxSize.Y, maxSize.Z));
// Generate source plane triangles
Vector3[] planePoints;
int[] planeInds;
NavigationMeshBuildUtils.BuildPlanePoints(ref plane, maxDiagonal, out planePoints, out planeInds);
Vector3 tangent, bitangent;
NavigationMeshBuildUtils.GenerateTangentBinormal(plane.Normal, out tangent, out bitangent);
// Calculate plane offset so that the plane always covers the whole range of the bounding box
Vector3 planeOffset = Vector3.Dot(boundingBox.Center, tangent) * tangent;
planeOffset += Vector3.Dot(boundingBox.Center, bitangent) * bitangent;
VertexPositionNormalTexture[] vertices = new VertexPositionNormalTexture[planePoints.Length];
for (int i = 0; i < planePoints.Length; i++)
{
vertices[i] = new VertexPositionNormalTexture(planePoints[i] + planeOffset, Vector3.UnitY, Vector2.Zero);
}
GeometricMeshData <VertexPositionNormalTexture> meshData = new GeometricMeshData <VertexPositionNormalTexture>(vertices, planeInds, true);
NavigationMeshInputBuilder inputBuilder = new NavigationMeshInputBuilder();
inputBuilder.AppendMeshData(meshData, Matrix.Identity);
return(inputBuilder);
}
/// <summary>
/// Marks tiles that should be built according to how much their geometry affects the navigation mesh and the bounding boxes specified for building
/// </summary>
private void MarkTiles(NavigationMeshInputBuilder inputBuilder, ref NavigationMeshBuildSettings buildSettings, ref NavigationAgentSettings agentSettings, HashSet <Point> tilesToBuild)
{
// Extend bounding box for agent size
BoundingBox boundingBoxToCheck = inputBuilder.BoundingBox;
NavigationMeshBuildUtils.ExtendBoundingBox(ref boundingBoxToCheck, new Vector3(agentSettings.Radius));
List <Point> newTileList = NavigationMeshBuildUtils.GetOverlappingTiles(buildSettings, boundingBoxToCheck);
foreach (Point p in newTileList)
{
tilesToBuild.Add(p);
}
}
/// <summary>
/// Performs the build of a navigation mesh
/// </summary>
/// <param name="buildSettings">The build settings to pass to recast</param>
/// <param name="agentSettings">A collection of agent settings to use, this will generate a layer in the navigation mesh for every agent settings in this collection (in the same order)</param>
/// <param name="includedCollisionGroups">The collision groups that will affect which colliders are considered solid</param>
/// <param name="boundingBoxes">A collection of bounding boxes to use as the region for which to generate navigation mesh tiles</param>
/// <param name="cancellationToken">A cancellation token to interrupt the build process</param>
/// <returns>The build result</returns>
public NavigationMeshBuildResult Build(NavigationMeshBuildSettings buildSettings, ICollection <NavigationMeshGroup> groups, CollisionFilterGroupFlags includedCollisionGroups,
ICollection <BoundingBox> boundingBoxes, CancellationToken cancellationToken)
{
var lastCache = oldNavigationMesh?.Cache;
var result = new NavigationMeshBuildResult();
if (groups.Count == 0)
{
Logger?.Warning("No group settings found");
result.Success = true;
result.NavigationMesh = new NavigationMesh();
return(result);
}
if (boundingBoxes.Count == 0)
{
Logger?.Warning("No bounding boxes found");
}
var settingsHash = groups?.ComputeHash() ?? 0;
settingsHash = (settingsHash * 397) ^ buildSettings.GetHashCode();
if (lastCache != null && lastCache.SettingsHash != settingsHash)
{
// Start from scratch if settings changed
oldNavigationMesh = null;
Logger?.Info("Build settings changed, doing a full rebuild");
}
// Copy colliders so the collection doesn't get modified
StaticColliderData[] collidersLocal;
lock (colliders)
{
collidersLocal = colliders.ToArray();
}
BuildInput(collidersLocal, includedCollisionGroups);
// Check if cache was cleared while building the input
lastCache = oldNavigationMesh?.Cache;
// The new navigation mesh that will be created
result.NavigationMesh = new NavigationMesh();
result.NavigationMesh.CellSize = buildSettings.CellSize;
result.NavigationMesh.TileSize = buildSettings.TileSize;
// Tile cache for this new navigation mesh
NavigationMeshCache newCache = result.NavigationMesh.Cache = new NavigationMeshCache();
newCache.SettingsHash = settingsHash;
// Generate global bounding box for planes
BoundingBox globalBoundingBox = BoundingBox.Empty;
foreach (var boundingBox in boundingBoxes)
{
globalBoundingBox = BoundingBox.Merge(boundingBox, globalBoundingBox);
}
// Combine input and collect tiles to build
NavigationMeshInputBuilder sceneNavigationMeshInputBuilder = new NavigationMeshInputBuilder();
foreach (var colliderData in collidersLocal)
{
if (colliderData.InputBuilder == null)
{
continue;
}
// Otherwise, skip building these tiles
sceneNavigationMeshInputBuilder.AppendOther(colliderData.InputBuilder);
newCache.Add(colliderData.Component, colliderData.InputBuilder, colliderData.Planes, colliderData.ParameterHash);
// Generate geometry for planes
foreach (var plane in colliderData.Planes)
{
sceneNavigationMeshInputBuilder.AppendOther(BuildPlaneGeometry(plane, globalBoundingBox));
}
}
// TODO: Generate tile local mesh input data
var inputVertices = sceneNavigationMeshInputBuilder.Points.ToArray();
var inputIndices = sceneNavigationMeshInputBuilder.Indices.ToArray();
// Enumerate over every layer, and build tiles for each of those layers using the provided agent settings
using (var groupEnumerator = groups.NotNull().GetEnumerator())
{
for (int layerIndex = 0; layerIndex < groups.Count; layerIndex++)
{
groupEnumerator.MoveNext();
var currentGroup = groupEnumerator.Current;
var currentAgentSettings = currentGroup.AgentSettings;
if (result.NavigationMesh.LayersInternal.ContainsKey(currentGroup.Id))
{
Logger.Error($"The same group can't be selected twice: {currentGroup}");
return(result);
}
HashSet <Point> tilesToBuild = new HashSet <Point>();
foreach (var colliderData in collidersLocal)
{
if (colliderData.InputBuilder == null)
{
continue;
}
if (colliderData.Processed)
{
MarkTiles(colliderData.InputBuilder, ref buildSettings, ref currentAgentSettings, tilesToBuild);
if (colliderData.Previous != null)
{
MarkTiles(colliderData.Previous.InputBuilder, ref buildSettings, ref currentAgentSettings, tilesToBuild);
}
}
}
// Check for removed colliders
if (lastCache != null)
{
foreach (var obj in lastCache.Objects)
{
if (!newCache.Objects.ContainsKey(obj.Key))
{
MarkTiles(obj.Value.InputBuilder, ref buildSettings, ref currentAgentSettings, tilesToBuild);
}
}
}
// Calculate updated/added bounding boxes
foreach (var boundingBox in boundingBoxes)
{
if (!lastCache?.BoundingBoxes.Contains(boundingBox) ?? true) // In the case of no case, mark all tiles in all bounding boxes to be rebuilt
{
var tiles = NavigationMeshBuildUtils.GetOverlappingTiles(buildSettings, boundingBox);
foreach (var tile in tiles)
{
tilesToBuild.Add(tile);
}
}
}
// Check for removed bounding boxes
if (lastCache != null)
{
foreach (var boundingBox in lastCache.BoundingBoxes)
{
if (!boundingBoxes.Contains(boundingBox))
{
var tiles = NavigationMeshBuildUtils.GetOverlappingTiles(buildSettings, boundingBox);
foreach (var tile in tiles)
{
tilesToBuild.Add(tile);
}
}
}
}
long buildTimeStamp = DateTime.UtcNow.Ticks;
ConcurrentCollector <Tuple <Point, NavigationMeshTile> > builtTiles = new ConcurrentCollector <Tuple <Point, NavigationMeshTile> >(tilesToBuild.Count);
Dispatcher.ForEach(tilesToBuild.ToArray(), tileCoordinate =>
{
// Allow cancellation while building tiles
if (cancellationToken.IsCancellationRequested)
{
return;
}
// Builds the tile, or returns null when there is nothing generated for this tile (empty tile)
NavigationMeshTile meshTile = BuildTile(tileCoordinate, buildSettings, currentAgentSettings, boundingBoxes,
inputVertices, inputIndices, buildTimeStamp);
// Add the result to the list of built tiles
builtTiles.Add(new Tuple <Point, NavigationMeshTile>(tileCoordinate, meshTile));
});
if (cancellationToken.IsCancellationRequested)
{
Logger?.Warning("Operation cancelled");
return(result);
}
// Add layer to the navigation mesh
var layer = new NavigationMeshLayer();
result.NavigationMesh.LayersInternal.Add(currentGroup.Id, layer);
// Copy tiles from from the previous build into the current
NavigationMeshLayer sourceLayer = null;
if (oldNavigationMesh != null && oldNavigationMesh.LayersInternal.TryGetValue(currentGroup.Id, out sourceLayer))
{
foreach (var sourceTile in sourceLayer.Tiles)
{
layer.TilesInternal.Add(sourceTile.Key, sourceTile.Value);
}
}
foreach (var p in builtTiles)
{
if (p.Item2 == null)
{
// Remove a tile
if (layer.TilesInternal.ContainsKey(p.Item1))
{
layer.TilesInternal.Remove(p.Item1);
}
}
else
{
// Set or update tile
layer.TilesInternal[p.Item1] = p.Item2;
}
}
// Add information about which tiles were updated to the result
if (tilesToBuild.Count > 0)
{
var layerUpdateInfo = new NavigationMeshLayerUpdateInfo();
layerUpdateInfo.GroupId = currentGroup.Id;
layerUpdateInfo.UpdatedTiles = tilesToBuild.ToList();
result.UpdatedLayers.Add(layerUpdateInfo);
}
}
}
// Check for removed layers
if (oldNavigationMesh != null)
{
var newGroups = groups.ToLookup(x => x.Id);
foreach (var oldLayer in oldNavigationMesh.Layers)
{
if (!newGroups.Contains(oldLayer.Key))
{
var updateInfo = new NavigationMeshLayerUpdateInfo();
updateInfo.UpdatedTiles.Capacity = oldLayer.Value.Tiles.Count;
foreach (var tile in oldLayer.Value.Tiles)
{
updateInfo.UpdatedTiles.Add(tile.Key);
}
result.UpdatedLayers.Add(updateInfo);
}
}
}
// Store bounding boxes in new tile cache
newCache.BoundingBoxes = new List <BoundingBox>(boundingBoxes);
// Update navigation mesh
oldNavigationMesh = result.NavigationMesh;
result.Success = true;
return(result);
}
/// <summary>
/// Rebuilds outdated triangle data for colliders and recalculates hashes storing everything in StaticColliderData
/// </summary>
private void BuildInput(StaticColliderData[] collidersLocal, CollisionFilterGroupFlags includedCollisionGroups)
{
NavigationMeshCache lastCache = oldNavigationMesh?.Cache;
bool clearCache = false;
Dispatcher.ForEach(collidersLocal, colliderData =>
{
var entity = colliderData.Component.Entity;
TransformComponent entityTransform = entity.Transform;
Matrix entityWorldMatrix = entityTransform.WorldMatrix;
NavigationMeshInputBuilder entityNavigationMeshInputBuilder = colliderData.InputBuilder = new NavigationMeshInputBuilder();
// Compute hash of collider and compare it with the previous build if there is one
colliderData.ParameterHash = NavigationMeshBuildUtils.HashEntityCollider(colliderData.Component, includedCollisionGroups);
colliderData.Previous = null;
if (lastCache?.Objects.TryGetValue(colliderData.Component.Id, out colliderData.Previous) ?? false)
{
if (colliderData.Previous.ParameterHash == colliderData.ParameterHash)
{
// In this case, we don't need to recalculate the geometry for this shape, since it wasn't changed
// here we take the triangle mesh from the previous build as the current
colliderData.InputBuilder = colliderData.Previous.InputBuilder;
colliderData.Planes.Clear();
colliderData.Planes.AddRange(colliderData.Previous.Planes);
colliderData.Processed = false;
return;
}
}
// Clear cache on removal of infinite planes
if (colliderData.Planes.Count > 0)
{
clearCache = true;
}
// Clear planes
colliderData.Planes.Clear();
// Return empty data for disabled colliders, filtered out colliders or trigger colliders
if (!colliderData.Component.Enabled || colliderData.Component.IsTrigger ||
!NavigationMeshBuildUtils.CheckColliderFilter(colliderData.Component, includedCollisionGroups))
{
colliderData.Processed = true;
return;
}
// Make sure shape is up to date
colliderData.Component.ComposeShape();
// Interate through all the colliders shapes while queueing all shapes in compound shapes to process those as well
Queue <ColliderShape> shapesToProcess = new Queue <ColliderShape>();
if (colliderData.Component.ColliderShape != null)
{
shapesToProcess.Enqueue(colliderData.Component.ColliderShape);
while (shapesToProcess.Count > 0)
{
var shape = shapesToProcess.Dequeue();
var shapeType = shape.GetType();
if (shapeType == typeof(BoxColliderShape))
{
var box = (BoxColliderShape)shape;
var boxDesc = GetColliderShapeDesc <BoxColliderShapeDesc>(box.Description);
Matrix transform = box.PositiveCenterMatrix * entityWorldMatrix;
var meshData = GeometricPrimitive.Cube.New(boxDesc.Size, toLeftHanded: true);
entityNavigationMeshInputBuilder.AppendMeshData(meshData, transform);
}
else if (shapeType == typeof(SphereColliderShape))
{
var sphere = (SphereColliderShape)shape;
var sphereDesc = GetColliderShapeDesc <SphereColliderShapeDesc>(sphere.Description);
Matrix transform = sphere.PositiveCenterMatrix * entityWorldMatrix;
var meshData = GeometricPrimitive.Sphere.New(sphereDesc.Radius, toLeftHanded: true);
entityNavigationMeshInputBuilder.AppendMeshData(meshData, transform);
}
else if (shapeType == typeof(CylinderColliderShape))
{
var cylinder = (CylinderColliderShape)shape;
var cylinderDesc = GetColliderShapeDesc <CylinderColliderShapeDesc>(cylinder.Description);
Matrix transform = cylinder.PositiveCenterMatrix * entityWorldMatrix;
var meshData = GeometricPrimitive.Cylinder.New(cylinderDesc.Height, cylinderDesc.Radius, toLeftHanded: true);
entityNavigationMeshInputBuilder.AppendMeshData(meshData, transform);
}
else if (shapeType == typeof(CapsuleColliderShape))
{
var capsule = (CapsuleColliderShape)shape;
var capsuleDesc = GetColliderShapeDesc <CapsuleColliderShapeDesc>(capsule.Description);
Matrix transform = capsule.PositiveCenterMatrix * entityWorldMatrix;
var meshData = GeometricPrimitive.Capsule.New(capsuleDesc.Length, capsuleDesc.Radius, toLeftHanded: true);
entityNavigationMeshInputBuilder.AppendMeshData(meshData, transform);
}
else if (shapeType == typeof(ConeColliderShape))
{
var cone = (ConeColliderShape)shape;
var coneDesc = GetColliderShapeDesc <ConeColliderShapeDesc>(cone.Description);
Matrix transform = cone.PositiveCenterMatrix * entityWorldMatrix;
var meshData = GeometricPrimitive.Cone.New(coneDesc.Radius, coneDesc.Height, toLeftHanded: true);
entityNavigationMeshInputBuilder.AppendMeshData(meshData, transform);
}
else if (shapeType == typeof(StaticPlaneColliderShape))
{
var planeShape = (StaticPlaneColliderShape)shape;
var planeDesc = GetColliderShapeDesc <StaticPlaneColliderShapeDesc>(planeShape.Description);
Matrix transform = entityWorldMatrix;
Plane plane = new Plane(planeDesc.Normal, planeDesc.Offset);
// Pre-Transform plane parameters
plane.Normal = Vector3.TransformNormal(planeDesc.Normal, transform);
plane.Normal.Normalize();
plane.D += Vector3.Dot(transform.TranslationVector, plane.Normal);
colliderData.Planes.Add(plane);
}
else if (shapeType == typeof(ConvexHullColliderShape))
{
var hull = (ConvexHullColliderShape)shape;
Matrix transform = hull.PositiveCenterMatrix * entityWorldMatrix;
// Convert hull indices to int
int[] indices = new int[hull.Indices.Count];
if (hull.Indices.Count % 3 != 0)
{
throw new InvalidOperationException("Physics hull does not consist of triangles");
}
for (int i = 0; i < hull.Indices.Count; i += 3)
{
indices[i] = (int)hull.Indices[i];
indices[i + 2] = (int)hull.Indices[i + 1]; // NOTE: Reversed winding to create left handed input
indices[i + 1] = (int)hull.Indices[i + 2];
}
entityNavigationMeshInputBuilder.AppendArrays(hull.Points.ToArray(), indices, transform);
}
else if (shapeType == typeof(CompoundColliderShape))
{
// Unroll compound collider shapes
var compound = (CompoundColliderShape)shape;
for (int i = 0; i < compound.Count; i++)
{
shapesToProcess.Enqueue(compound[i]);
}
}
}
}
// Clear cache on addition of infinite planes
if (colliderData.Planes.Count > 0)
{
clearCache = true;
}
// Mark collider as processed
colliderData.Processed = true;
});
if (clearCache && oldNavigationMesh != null)
{
oldNavigationMesh = null;
}
}
private NavigationMeshTile BuildTile(Point tileCoordinate, NavigationMeshBuildSettings buildSettings, NavigationAgentSettings agentSettings,
ICollection <BoundingBox> boundingBoxes, Vector3[] inputVertices, int[] inputIndices, long buildTimeStamp)
{
NavigationMeshTile meshTile = null;
// Include bounding boxes in tile height range
BoundingBox tileBoundingBox = NavigationMeshBuildUtils.CalculateTileBoundingBox(buildSettings, tileCoordinate);
float minimumHeight = float.MaxValue;
float maximumHeight = float.MinValue;
bool shouldBuildTile = false;
foreach (var boundingBox in boundingBoxes)
{
if (boundingBox.Intersects(ref tileBoundingBox))
{
maximumHeight = Math.Max(maximumHeight, boundingBox.Maximum.Y);
minimumHeight = Math.Min(minimumHeight, boundingBox.Minimum.Y);
shouldBuildTile = true;
}
}
NavigationMeshBuildUtils.SnapBoundingBoxToCellHeight(buildSettings, ref tileBoundingBox);
// Skip tiles that do not overlap with any bounding box
if (shouldBuildTile)
{
// Set tile's minimum and maximum height
tileBoundingBox.Minimum.Y = minimumHeight;
tileBoundingBox.Maximum.Y = maximumHeight;
unsafe
{
IntPtr builder = Navigation.CreateBuilder();
// Turn build settings into native structure format
Navigation.BuildSettings internalBuildSettings = new Navigation.BuildSettings
{
// Tile settings
BoundingBox = tileBoundingBox,
TilePosition = tileCoordinate,
TileSize = buildSettings.TileSize,
// General build settings
CellHeight = buildSettings.CellHeight,
CellSize = buildSettings.CellSize,
RegionMinArea = buildSettings.MinRegionArea,
RegionMergeArea = buildSettings.RegionMergeArea,
EdgeMaxLen = buildSettings.MaxEdgeLen,
EdgeMaxError = buildSettings.MaxEdgeError,
DetailSampleDist = buildSettings.DetailSamplingDistance,
DetailSampleMaxError = buildSettings.MaxDetailSamplingError,
// Agent settings
AgentHeight = agentSettings.Height,
AgentRadius = agentSettings.Radius,
AgentMaxClimb = agentSettings.MaxClimb,
AgentMaxSlope = agentSettings.MaxSlope.Degrees
};
Navigation.SetSettings(builder, new IntPtr(&internalBuildSettings));
IntPtr buildResultPtr = Navigation.Build(builder, inputVertices, inputVertices.Length, inputIndices, inputIndices.Length);
Navigation.GeneratedData *generatedDataPtr = (Navigation.GeneratedData *)buildResultPtr;
if (generatedDataPtr->Success && generatedDataPtr->NavmeshDataLength > 0)
{
meshTile = new NavigationMeshTile();
// Copy the generated navigationMesh data
meshTile.Data = new byte[generatedDataPtr->NavmeshDataLength + sizeof(long)];
Marshal.Copy(generatedDataPtr->NavmeshData, meshTile.Data, 0, generatedDataPtr->NavmeshDataLength);
// Append time stamp
byte[] timeStamp = BitConverter.GetBytes(buildTimeStamp);
for (int i = 0; i < timeStamp.Length; i++)
{
meshTile.Data[meshTile.Data.Length - sizeof(long) + i] = timeStamp[i];
}
List <Vector3> outputVerts = new List <Vector3>();
if (generatedDataPtr->NumNavmeshVertices > 0)
{
Vector3 *navmeshVerts = (Vector3 *)generatedDataPtr->NavmeshVertices;
for (int j = 0; j < generatedDataPtr->NumNavmeshVertices; j++)
{
outputVerts.Add(navmeshVerts[j]);
}
}
Navigation.DestroyBuilder(builder);
}
}
}
return(meshTile);
}