Add NavMesh Modifier Volume actor type

Source/Editor/SceneGraph/Actors/NavModifierVolumeNode.cs

@@ -0,0 +1,20 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+using FlaxEngine;
+
+namespace FlaxEditor.SceneGraph.Actors
+{
+    /// <summary>
+    /// Actor node for <see cref="NavModifierVolume"/>.
+    /// </summary>
+    /// <seealso cref="BoxVolumeNode" />
+    [HideInEditor]
+    public sealed class NavModifierVolumeNode : BoxVolumeNode
+    {
+        /// <inheritdoc />
+        public NavModifierVolumeNode(Actor actor)
+        : base(actor)
+        {
+        }
+    }
+}

Source/Editor/SceneGraph/SceneGraphFactory.cs

@@ -62,6 +62,7 @@ namespace FlaxEditor.SceneGraph
             CustomNodesTypes.Add(typeof(NavMeshBoundsVolume), typeof(NavMeshBoundsVolumeNode));
             CustomNodesTypes.Add(typeof(BoxVolume), typeof(BoxVolumeNode));
             CustomNodesTypes.Add(typeof(NavLink), typeof(NavLinkNode));
+            CustomNodesTypes.Add(typeof(NavModifierVolume), typeof(NavModifierVolumeNode));
             CustomNodesTypes.Add(typeof(ParticleEffect), typeof(ParticleEffectNode));
             CustomNodesTypes.Add(typeof(SceneAnimationPlayer), typeof(SceneAnimationPlayerNode));
         }

Source/Editor/Windows/SceneTreeWindow.Actors.cs

@@ -97,7 +97,8 @@ namespace FlaxEditor.Windows
                     new KeyValuePair<string, Type>("Audio Listener", typeof(AudioListener)),
                     new KeyValuePair<string, Type>("Scene Animation", typeof(SceneAnimationPlayer)),
                     new KeyValuePair<string, Type>("Nav Mesh Bounds Volume", typeof(NavMeshBoundsVolume)),
-                    new KeyValuePair<string, Type>("Nav Mesh Link", typeof(NavLink)),
+                    new KeyValuePair<string, Type>("Nav Link", typeof(NavLink)),
+                    new KeyValuePair<string, Type>("Nav Modifier Volume", typeof(NavModifierVolume)),
                 }
             },
             new ActorsGroup

Source/Editor/Windows/ToolboxWindow.cs

@@ -165,7 +165,8 @@ namespace FlaxEditor.Windows
             groupOther.AddChild(CreateActorItem("Empty Actor", typeof(EmptyActor)));
             groupOther.AddChild(CreateActorItem("Scene Animation", typeof(SceneAnimationPlayer)));
             groupOther.AddChild(CreateActorItem("Nav Mesh Bounds Volume", typeof(NavMeshBoundsVolume)));
-            groupOther.AddChild(CreateActorItem("Nav Mesh Link", typeof(NavLink)));
+            groupOther.AddChild(CreateActorItem("Nav Link", typeof(NavLink)));
+            groupOther.AddChild(CreateActorItem("Nav Modifier Volume", typeof(NavModifierVolume)));
 
             var groupGui = CreateGroupWithList(actorGroups, "GUI");
             groupGui.AddChild(CreateActorItem("UI Control", typeof(UIControl)));

Source/Engine/Navigation/NavMeshBoundsVolume.h

@@ -6,7 +6,7 @@
 #include "NavigationTypes.h"
 
 /// <summary>
-/// A special type of volume that defines the areas of the scene in which navigation meshes are generated.
+/// A special type of volume that defines the area of the scene in which navigation meshes are generated.
 /// </summary>
 API_CLASS() class FLAXENGINE_API NavMeshBoundsVolume : public BoxVolume
 {

Source/Engine/Navigation/NavMeshBuilder.cpp

@@ -7,6 +7,7 @@
 #include "NavigationSettings.h"
 #include "NavMeshBoundsVolume.h"
 #include "NavLink.h"
+#include "NavModifierVolume.h"
 #include "NavMeshRuntime.h"
 #include "Engine/Core/Math/BoundingBox.h"
 #include "Engine/Core/Math/VectorInt.h"
@@ -55,8 +56,14 @@ struct OffMeshLink
     int32 Id;
 };
 
+struct Modifier
+{
+    BoundingBox Bounds;
+};
+
 struct NavigationSceneRasterization
 {
+    NavMesh* NavMesh;
     BoundingBox TileBoundsNavMesh;
     Matrix WorldToNavMesh;
     rcContext* Context;
@@ -66,18 +73,21 @@ struct NavigationSceneRasterization
     Array<Vector3> VertexBuffer;
     Array<int32> IndexBuffer;
     Array<OffMeshLink>* OffMeshLinks;
+    Array<Modifier>* Modifiers;
     const bool IsWorldToNavMeshIdentity;
 
-    NavigationSceneRasterization(const BoundingBox& tileBoundsNavMesh, const Matrix& worldToNavMesh, rcContext* context, rcConfig* config, rcHeightfield* heightfield, Array<OffMeshLink>* offMeshLinks)
+    NavigationSceneRasterization(::NavMesh* navMesh, const BoundingBox& tileBoundsNavMesh, const Matrix& worldToNavMesh, rcContext* context, rcConfig* config, rcHeightfield* heightfield, Array<OffMeshLink>* offMeshLinks, Array<Modifier>* modifiers)
         : TileBoundsNavMesh(tileBoundsNavMesh)
         , WorldToNavMesh(worldToNavMesh)
         , IsWorldToNavMeshIdentity(worldToNavMesh.IsIdentity())
     {
+        NavMesh = navMesh;
         Context = context;
         Config = config;
         Heightfield = heightfield;
         WalkableThreshold = Math::Cos(config->walkableSlopeAngle * DegreesToRadians);
         OffMeshLinks = offMeshLinks;
+        Modifiers = modifiers;
     }
 
     void RasterizeTriangles()
@@ -280,16 +290,30 @@ struct NavigationSceneRasterization
 
             e.OffMeshLinks->Add(link);
         }
+        else if (const auto* navModifierVolume = dynamic_cast<NavModifierVolume*>(actor))
+        {
+            if (navModifierVolume->AgentsMask.IsNavMeshSupported(e.NavMesh->Properties))
+            {
+                PROFILE_CPU_NAMED("NavModifierVolume");
+
+                Modifier modifier;
+                OrientedBoundingBox bounds = navModifierVolume->GetOrientedBox();
+                bounds.Transform(e.WorldToNavMesh);
+                bounds.GetBoundingBox(modifier.Bounds);
+
+                e.Modifiers->Add(modifier);
+            }
+        }
 
         return true;
     }
 };
 
-void RasterizeGeometry(const BoundingBox& tileBoundsNavMesh, const Matrix& worldToNavMesh, rcContext* context, rcConfig* config, rcHeightfield* heightfield, Array<OffMeshLink>* offMeshLinks)
+void RasterizeGeometry(NavMesh* navMesh, const BoundingBox& tileBoundsNavMesh, const Matrix& worldToNavMesh, rcContext* context, rcConfig* config, rcHeightfield* heightfield, Array<OffMeshLink>* offMeshLinks, Array<Modifier>* modifiers)
 {
     PROFILE_CPU_NAMED("RasterizeGeometry");
 
-    NavigationSceneRasterization rasterization(tileBoundsNavMesh, worldToNavMesh, context, config, heightfield, offMeshLinks);
+    NavigationSceneRasterization rasterization(navMesh, tileBoundsNavMesh, worldToNavMesh, context, config, heightfield, offMeshLinks, modifiers);
     Function<bool(Actor*, NavigationSceneRasterization&)> treeWalkFunction(NavigationSceneRasterization::Walk);
     SceneQuery::TreeExecute<NavigationSceneRasterization&>(treeWalkFunction, rasterization);
 }
@@ -389,7 +413,8 @@ bool GenerateTile(NavMesh* navMesh, NavMeshRuntime* runtime, int32 x, int32 y, B
     }
 
     Array<OffMeshLink> offMeshLinks;
-    RasterizeGeometry(tileBoundsNavMesh, worldToNavMesh, &context, &config, heightfield, &offMeshLinks);
+    Array<Modifier> modifiers;
+    RasterizeGeometry(navMesh, tileBoundsNavMesh, worldToNavMesh, &context, &config, heightfield, &offMeshLinks, &modifiers);
 
     rcFilterLowHangingWalkableObstacles(&context, config.walkableClimb, *heightfield);
     rcFilterLedgeSpans(&context, config.walkableHeight, config.walkableClimb, *heightfield);
@@ -415,6 +440,12 @@ bool GenerateTile(NavMesh* navMesh, NavMeshRuntime* runtime, int32 x, int32 y, B
         return true;
     }
 
+    // Mark areas
+    for (auto& modifier : modifiers)
+    {
+        rcMarkBoxArea(&context, &modifier.Bounds.Minimum.X, &modifier.Bounds.Maximum.X, RC_NULL_AREA, *compactHeightfield);
+    }
+
     if (!rcBuildDistanceField(&context, *compactHeightfield))
     {
         LOG(Warning, "Could not generate navmesh: Could not build distance field.");
@@ -468,7 +499,7 @@ bool GenerateTile(NavMesh* navMesh, NavMeshRuntime* runtime, int32 x, int32 y, B
 
     for (int i = 0; i < polyMesh->npolys; i++)
     {
-        polyMesh->flags[i] = polyMesh->areas[i] == RC_WALKABLE_AREA ? 1 : 0;
+        polyMesh->flags[i] = polyMesh->areas[i] != RC_NULL_AREA ? 1 : 0;
     }
 
     if (polyMesh->nverts == 0)

Source/Engine/Navigation/NavModifierVolume.cpp

@@ -0,0 +1,54 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#include "NavModifierVolume.h"
+#include "Engine/Level/Scene/Scene.h"
+#include "Engine/Serialization/Serialization.h"
+#if USE_EDITOR
+#include "Editor/Editor.h"
+#include "Editor/Managed/ManagedEditor.h"
+#include "NavMeshBuilder.h"
+#endif
+
+NavModifierVolume::NavModifierVolume(const SpawnParams& params)
+    : BoxVolume(params)
+{
+    _size = 100.0f;
+}
+
+void NavModifierVolume::Serialize(SerializeStream& stream, const void* otherObj)
+{
+    // Base
+    BoxVolume::Serialize(stream, otherObj);
+
+    SERIALIZE_GET_OTHER_OBJ(NavModifierVolume);
+
+    SERIALIZE_MEMBER(AgentsMask, AgentsMask.Mask);
+}
+
+void NavModifierVolume::Deserialize(DeserializeStream& stream, ISerializeModifier* modifier)
+{
+    // Base
+    BoxVolume::Deserialize(stream, modifier);
+
+    DESERIALIZE_MEMBER(AgentsMask, AgentsMask.Mask);
+}
+
+#if USE_EDITOR
+
+void NavModifierVolume::OnBoundsChanged(const BoundingBox& prevBounds)
+{
+    // Auto-rebuild modified navmesh area
+    if (IsDuringPlay() && IsActiveInHierarchy() && !Editor::IsPlayMode && Editor::Managed->CanAutoBuildNavMesh())
+    {
+        BoundingBox dirtyBounds;
+        BoundingBox::Merge(prevBounds, _box, dirtyBounds);
+        NavMeshBuilder::Build(GetScene(), dirtyBounds, ManagedEditor::ManagedEditorOptions.AutoRebuildNavMeshTimeoutMs);
+    }
+}
+
+Color NavModifierVolume::GetWiresColor()
+{
+    return Color::Red;
+}
+
+#endif

Source/Engine/Navigation/NavModifierVolume.h

@@ -0,0 +1,35 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#include "Engine/Level/Actors/BoxVolume.h"
+#include "NavigationTypes.h"
+
+/// <summary>
+/// A special type of volume that defines the area of the scene in which navigation is restricted (eg. higher traversal cost or dynamic obstacle block).
+/// </summary>
+API_CLASS() class FLAXENGINE_API NavModifierVolume : public BoxVolume
+{
+DECLARE_SCENE_OBJECT(NavModifierVolume);
+public:
+
+    /// <summary>
+    /// The agent types used by this navmesh modifier volume (from navigation settings). Can be used to adjust navmesh for a certain set of agents.
+    /// </summary>
+    API_FIELD(Attributes="EditorDisplay(\"Box Volume\"), EditorOrder(10)")
+    NavAgentMask AgentsMask;
+
+public:
+
+    // [BoxVolume]
+    void Serialize(SerializeStream& stream, const void* otherObj) override;
+    void Deserialize(DeserializeStream& stream, ISerializeModifier* modifier) override;
+
+protected:
+
+    // [BoxVolume]
+#if USE_EDITOR
+    void OnBoundsChanged(const BoundingBox& prevBounds) override;
+    Color GetWiresColor() override;
+#endif
+};