Game Engine: Level of detail support and tools

Levels of detail can be added and modified in the object panel. The object
panel also contains new tools for generating levels of detail, setting up
levels of detail based on object names (useful for importing), and
clearing an object's level of detail settings. This is meant as a game
engine feature, though the level of details settings can be previewed in
the viewport.

Reviewed By: moguri, nexyon, brecht

Differential Revision: http://developer.blender.org/D109

6 files changed, 79 insertions, 0 deletions

diff --git a/source/gameengine/Ketsji/KX_Dome.cpp b/source/gameengine/Ketsji/KX_Dome.cpp
index f87d4799abc..43d74487542 100644
--- a/source/gameengine/Ketsji/KX_Dome.cpp
+++ b/source/gameengine/Ketsji/KX_Dome.cpp
@@ -2045,5 +2045,8 @@ void KX_Dome::RenderDomeFrame(KX_Scene* scene, KX_Camera* cam, int i)
 
 	scene->CalculateVisibleMeshes(m_rasterizer,cam);
 	scene->RenderBuckets(camtrans, m_rasterizer);
+
+	// update levels of detail
+	scene->UpdateObjectLods();
 }
 
diff --git a/source/gameengine/Ketsji/KX_GameObject.cpp b/source/gameengine/Ketsji/KX_GameObject.cpp
index d3b5a987138..8b7e6667fae 100644
--- a/source/gameengine/Ketsji/KX_GameObject.cpp
+++ b/source/gameengine/Ketsji/KX_GameObject.cpp
@@ -71,6 +71,8 @@ typedef unsigned long uint_ptr;
 #include "NG_NetworkScene.h" //Needed for sendMessage()
 #include "KX_ObstacleSimulation.h"
 
+#include "BKE_object.h"
+
 #include "BL_ActionManager.h"
 #include "BL_Action.h"
 
@@ -732,6 +734,43 @@ void KX_GameObject::RemoveMeshes()
 	m_meshes.clear();
 }
 
+void KX_GameObject::AddLodMesh(RAS_MeshObject* mesh)
+{
+	m_lodmeshes.push_back(mesh);
+}
+
+void KX_GameObject::UpdateLod(MT_Vector3 &cam_pos)
+{
+	// Handle dupligroups
+	if (this->m_pInstanceObjects) {
+		KX_GameObject * instob;
+		int count = this->m_pInstanceObjects->GetCount();
+		for (int i = 0; i < count; i++) {
+			instob = (KX_GameObject*)this->m_pInstanceObjects->GetValue(i);
+			instob->UpdateLod(cam_pos);
+		}
+	}
+
+	if (this->m_lodmeshes.empty()) return;
+
+	MT_Vector3 delta = this->NodeGetWorldPosition() - cam_pos;
+	float distance2 = delta.length2();
+
+	int level = 0;
+	Object *bob = this->GetBlenderObject();
+	LodLevel *lod = (LodLevel*) bob->lodlevels.first;
+	for (; lod; lod = lod->next, level++) {
+		if (!lod->source) level--;
+		if (!lod->next || lod->next->distance * lod->next->distance > distance2) break;
+	}
+
+	RAS_MeshObject *mesh = this->m_lodmeshes[level];
+
+	if (mesh != this->m_meshes[0]) {
+		this->GetScene()->ReplaceMesh(this, mesh, true, false);
+	}
+}
+
 void KX_GameObject::UpdateTransform()
 {
 	// HACK: saves function call for dynamic object, they are handled differently
diff --git a/source/gameengine/Ketsji/KX_GameObject.h b/source/gameengine/Ketsji/KX_GameObject.h
index 12aac68365b..ac0afca91eb 100644
--- a/source/gameengine/Ketsji/KX_GameObject.h
+++ b/source/gameengine/Ketsji/KX_GameObject.h
@@ -87,6 +87,7 @@ protected:
 	STR_String							m_text;
 	int									m_layer;
 	std::vector<RAS_MeshObject*>		m_meshes;
+	std::vector<RAS_MeshObject*>		m_lodmeshes;
 	SG_QList							m_meshSlots;	// head of mesh slots of this 
 	struct Object*						m_pBlenderObject;
 	struct Object*						m_pBlenderGroupObject;
@@ -772,6 +773,23 @@ public:
 	}
 
 	/**
+	 * Add a level of detail mesh to the object. These should
+	 * be added in order.
+	 */
+		void
+	AddLodMesh(
+		RAS_MeshObject* mesh
+	);
+
+	/**
+	 * Updates the current lod level based on distance from camera.
+	 */
+		void
+	UpdateLod(
+		MT_Vector3 &cam_pos
+	);
+
+	/**
 	 * Pick out a mesh associated with the integer 'num'.
 	 */
 		RAS_MeshObject*
diff --git a/source/gameengine/Ketsji/KX_KetsjiEngine.cpp b/source/gameengine/Ketsji/KX_KetsjiEngine.cpp
index 0e9e2cd8328..3aa5a9f4f0e 100644
--- a/source/gameengine/Ketsji/KX_KetsjiEngine.cpp
+++ b/source/gameengine/Ketsji/KX_KetsjiEngine.cpp
@@ -1315,6 +1315,9 @@ void KX_KetsjiEngine::RenderFrame(KX_Scene* scene, KX_Camera* cam)
 
 	scene->CalculateVisibleMeshes(m_rasterizer,cam);
 
+	// update levels of detail
+	scene->UpdateObjectLods();
+
 	m_logger->StartLog(tc_rasterizer, m_kxsystem->GetTimeInSeconds(), true);
 	SG_SetActiveStage(SG_STAGE_RENDER);
 
diff --git a/source/gameengine/Ketsji/KX_Scene.cpp b/source/gameengine/Ketsji/KX_Scene.cpp
index 70924c65519..4a147b4eb60 100644
--- a/source/gameengine/Ketsji/KX_Scene.cpp
+++ b/source/gameengine/Ketsji/KX_Scene.cpp
@@ -1726,6 +1726,19 @@ void KX_Scene::RenderFonts()
 	}
 }
 
+void KX_Scene::UpdateObjectLods(void)
+{
+	KX_GameObject* gameobj;
+	MT_Vector3 cam_pos = this->m_active_camera->NodeGetWorldPosition();
+
+	for (int i = 0; i < this->GetObjectList()->GetCount(); i++) {
+		gameobj = (KX_GameObject*) GetObjectList()->GetValue(i);
+		if (!gameobj->GetCulled()){
+			gameobj->UpdateLod(cam_pos);
+		}
+	}
+}
+
 void KX_Scene::UpdateObjectActivity(void) 
 {
 	if (m_activity_culling) {
diff --git a/source/gameengine/Ketsji/KX_Scene.h b/source/gameengine/Ketsji/KX_Scene.h
index ee2a994d53c..50fac923fe2 100644
--- a/source/gameengine/Ketsji/KX_Scene.h
+++ b/source/gameengine/Ketsji/KX_Scene.h
@@ -544,6 +544,9 @@ public:
 
 	// Resume a suspended scene.
 	void Resume();
+
+	// Update the mesh for objects based on level of detail settings
+	void UpdateObjectLods(void);
 	
 	// Update the activity box settings for objects in this scene, if needed.
 	void UpdateObjectActivity(void);