/// <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);
}
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);
}