leaf-based navigation mesh

got an idea to use navigation volumes for a plugin that tells players where to go. 3D volumes are simpler to link together than flat floor polygons with differing heights, and allow more pathing possibilities. The mesh is the set of empty leaves in the clipnode tree for a crouching player. Leaves are linked together by their overlapping face regions.

Author: wootguy

CMakeLists.txt

@@ -33,10 +33,14 @@ set(SOURCE_FILES
 	src/util/Polygon3D.h	src/util/Polygon3D.cpp
 	src/util/Line2D.h		src/util/Line2D.cpp
 	src/util/PolyOctree.h	src/util/PolyOctree.cpp
-	src/bsp/NavMesh.h		src/bsp/NavMesh.cpp
-	src/bsp/NavMeshGenerator.h		src/bsp/NavMeshGenerator.cpp
 	src/globals.h			src/globals.cpp
 
+	# Navigation meshes
+	src/nav/NavMesh.h				src/nav/NavMesh.cpp
+	src/nav/NavMeshGenerator.h		src/nav/NavMeshGenerator.cpp
+	src/nav/LeafNavMeshGenerator.h	src/nav/LeafNavMeshGenerator.cpp
+	src/nav/LeafNavMesh.h			src/nav/LeafNavMesh.cpp
+	
 	# OpenGL rendering
 	src/gl/shaders.h			src/gl/shaders.cpp
 	src/gl/primitives.h			src/gl/primitives.cpp
@@ -83,6 +87,7 @@ include_directories(src/editor)
 include_directories(src/gl)
 include_directories(src/qtools)
 include_directories(src/util)
+include_directories(src/nav)
 include_directories(imgui)
 include_directories(imgui/examples)
 include_directories(imgui/backends)
@@ -186,6 +191,16 @@ if(MSVC)
 												src/util/Line2D.cpp
 												src/util/PolyOctree.cpp
 												src/util/mat4x4.cpp)
+												
+	source_group("Header Files\\nav" FILES		src/nav/NavMesh.h
+												src/nav/NavMeshGenerator.h
+												src/nav/LeafNavMeshGenerator.h
+												src/nav/LeafNavMesh.h)
+												
+	source_group("Source Files\\nav" FILES		src/nav/NavMesh.cpp
+												src/nav/NavMeshGenerator.cpp
+												src/nav/LeafNavMeshGenerator.cpp
+												src/nav/LeafNavMesh.cpp)
 
 	source_group("Header Files\\util\\lib" FILES	src/util/lodepng.h)
 

src/bsp/Bsp.cpp

@@ -4418,28 +4418,55 @@ const char* Bsp::getLeafContentsName(int32_t contents) {
 	}
 }
 
-int Bsp::get_leaf(vec3 pos) {
-	int iNode = models->iHeadnodes[0];
+int Bsp::get_leaf(vec3 pos, int hull) {
+	int iNode = models->iHeadnodes[hull];
+
+	if (hull == 0) {
+		while (iNode >= 0)
+		{
+			BSPNODE& node = nodes[iNode];
+			BSPPLANE& plane = planes[node.iPlane];
+
+			float d = dotProduct(plane.vNormal, pos) - plane.fDist;
+			if (d < 0) {
+				iNode = node.iChildren[1];
+			}
+			else {
+				iNode = node.iChildren[0];
+			}
+		}
+
+		return ~iNode;
+	}
+
+	int lastNode = -1;
+	int lastSide = 0;
 
 	while (iNode >= 0)
 	{
-		BSPNODE& node = nodes[iNode];
+		BSPCLIPNODE& node = clipnodes[iNode];
 		BSPPLANE& plane = planes[node.iPlane];
 
 		float d = dotProduct(plane.vNormal, pos) - plane.fDist;
 		if (d < 0) {
+			lastNode = iNode;
 			iNode = node.iChildren[1];
+			lastSide = 1;
 		}
 		else {
+			lastNode = iNode;
 			iNode = node.iChildren[0];
+			lastSide = 0;
 		}
 	}
 
-	return ~iNode;
+	// clipnodes don't have leaf structs, so generate an id based on the last clipnode index and
+	// the side of the plane that would be recursed to reach the leaf contents, if there were a leaf
+	return lastNode * 2 + lastSide;
 }
 
 bool Bsp::is_leaf_visible(int ileaf, vec3 pos) {
-	int ipvsLeaf = get_leaf(pos);
+	int ipvsLeaf = get_leaf(pos, 0);
 	BSPLEAF& pvsLeaf = leaves[ipvsLeaf];
 
 	int p = pvsLeaf.nVisOffset; // pvs offset
@@ -4491,7 +4518,7 @@ bool Bsp::is_face_visible(int faceIdx, vec3 pos, vec3 angles) {
 }
 
 int Bsp::count_visible_polys(vec3 pos, vec3 angles) {
-	int ipvsLeaf = get_leaf(pos);
+	int ipvsLeaf = get_leaf(pos, 0);
 	BSPLEAF& pvsLeaf = leaves[ipvsLeaf];
 
 	int p = pvsLeaf.nVisOffset; // pvs offset

src/bsp/Bsp.h

@@ -103,7 +103,7 @@ class Bsp
 	int count_visible_polys(vec3 pos, vec3 angles);
 
 	// get leaf index from world position
-	int get_leaf(vec3 pos);
+	int get_leaf(vec3 pos, int hull);
 
 	// strips a collision hull from the given model index
 	// and redirects to the given hull, if redirect>0

src/editor/BspRenderer.cpp

@@ -7,6 +7,7 @@
 #include "Clipper.h"
 #include "Polygon3D.h"
 #include "NavMeshGenerator.h"
+#include "LeafNavMeshGenerator.h"
 #include "PointEntRenderer.h"
 #include "Texture.h"
 #include "LightmapNode.h"
@@ -956,6 +957,129 @@ void BspRenderer::generateNavMeshBuffer() {
 	file.close();
 }
 
+void BspRenderer::generateLeafNavMeshBuffer() {
+	int hull = 3;
+	RenderClipnodes* renderClip = &renderClipnodes[0];
+	renderClip->clipnodeBuffer[hull] = NULL;
+	renderClip->wireframeClipnodeBuffer[hull] = NULL;
+
+	LeafNavMesh* navMesh = LeafNavMeshGenerator().generate(map, hull);
+	g_app->debugLeafNavMesh = navMesh;
+
+	static COLOR4 hullColors[] = {
+		COLOR4(255, 255, 255, 128),
+		COLOR4(96, 255, 255, 128),
+		COLOR4(255, 96, 255, 128),
+		COLOR4(255, 255, 96, 128),
+	};
+	COLOR4 color = hullColors[hull];
+
+	vector<cVert> allVerts;
+	vector<cVert> wireframeVerts;
+	vector<FaceMath> faceMaths;
+
+	for (int lf = 0; lf < navMesh->numLeaves; lf++) {
+		LeafMesh& mesh = navMesh->leaves[lf];
+
+		color = hullColors[hull];
+		static int r = 0;
+		r = (r + 1) % 8;
+		if (r == 0) {
+			color = COLOR4(255, 32, 32, 128);
+		}
+		else if (r == 1) {
+			color = COLOR4(255, 255, 32, 128);
+		}
+		else if (r == 2) {
+			color = COLOR4(255, 32, 255, 128);
+		}
+		else if (r == 3) {
+			color = COLOR4(255, 128, 255, 128);
+		}
+		else if (r == 4) {
+			color = COLOR4(32, 32, 255, 128);
+		}
+		else if (r == 5) {
+			color = COLOR4(32, 255, 255, 128);
+		}
+		else if (r == 6) {
+			color = COLOR4(32, 128, 255, 128);
+		}
+		else if (r == 7) {
+			color = COLOR4(32, 255, 128, 128);
+		}
+
+		for (int m = 0; m < mesh.leafFaces.size(); m++) {
+			Polygon3D& poly = mesh.leafFaces[m];
+
+			vec3 normal = poly.plane_z;
+
+			// calculations for face picking
+			{
+				FaceMath faceMath;
+				faceMath.normal = normal;
+				faceMath.fdist = poly.fdist;
+				faceMath.worldToLocal = poly.worldToLocal;
+				faceMath.localVerts = poly.localVerts;
+				faceMaths.push_back(faceMath);
+			}
+
+			// create the verts for rendering
+			{
+				vector<vec3> renderVerts;
+				renderVerts.resize(poly.verts.size());
+				for (int i = 0; i < poly.verts.size(); i++) {
+					renderVerts[i] = poly.verts[i].flip();
+				}
+
+				COLOR4 wireframeColor = { 0, 0, 0, 255 };
+				for (int k = 0; k < renderVerts.size(); k++) {
+					wireframeVerts.push_back(cVert(renderVerts[k], wireframeColor));
+					wireframeVerts.push_back(cVert(renderVerts[(k + 1) % renderVerts.size()], wireframeColor));
+				}
+
+				vec3 lightDir = vec3(1, 1, -1).normalize();
+				float dot = (dotProduct(normal, lightDir) + 1) / 2.0f;
+				if (dot > 0.5f) {
+					dot = dot * dot;
+				}
+				COLOR4 faceColor = color * (dot);
+
+				// convert from TRIANGLE_FAN style verts to TRIANGLES
+				for (int k = 2; k < renderVerts.size(); k++) {
+					allVerts.push_back(cVert(renderVerts[0], faceColor));
+					allVerts.push_back(cVert(renderVerts[k - 1], faceColor));
+					allVerts.push_back(cVert(renderVerts[k], faceColor));
+				}
+			}
+		}
+	}
+
+	cVert* output = new cVert[allVerts.size()];
+	for (int i = 0; i < allVerts.size(); i++) {
+		output[i] = allVerts[i];
+	}
+
+	cVert* wireOutput = new cVert[wireframeVerts.size()];
+	for (int i = 0; i < wireframeVerts.size(); i++) {
+		wireOutput[i] = wireframeVerts[i];
+	}
+
+	if (allVerts.size() == 0 || wireframeVerts.size() == 0) {
+		renderClip->clipnodeBuffer[hull] = NULL;
+		renderClip->wireframeClipnodeBuffer[hull] = NULL;
+		return;
+	}
+
+	renderClip->clipnodeBuffer[hull] = new VertexBuffer(colorShader, COLOR_4B | POS_3F, output, allVerts.size());
+	renderClip->clipnodeBuffer[hull]->ownData = true;
+
+	renderClip->wireframeClipnodeBuffer[hull] = new VertexBuffer(colorShader, COLOR_4B | POS_3F, wireOutput, wireframeVerts.size());
+	renderClip->wireframeClipnodeBuffer[hull]->ownData = true;
+
+	renderClip->faceMaths[hull] = faceMaths;
+}
+
 void BspRenderer::generateClipnodeBuffer(int modelIdx) {
 	BSPMODEL& model = map->models[modelIdx];
 	RenderClipnodes* renderClip = &renderClipnodes[modelIdx];
@@ -1120,6 +1244,7 @@ void BspRenderer::generateClipnodeBuffer(int modelIdx) {
 
 	if (modelIdx == 0) {
 		//generateNavMeshBuffer();
+		//generateLeafNavMeshBuffer();
 	}
 }
 

src/editor/BspRenderer.h

@@ -205,6 +205,7 @@ class BspRenderer {
 	void loadClipnodes();
 	void generateClipnodeBuffer(int modelIdx);
 	void generateNavMeshBuffer();
+	void generateLeafNavMeshBuffer();
 	void deleteRenderModel(RenderModel* renderModel);
 	void deleteRenderModelClipnodes(RenderClipnodes* renderModel);
 	void deleteRenderClipnodes();

src/editor/Gui.cpp

@@ -1951,6 +1951,9 @@ void Gui::drawDebugWidget() {
 							if (i == 0) {
 								ImGui::Text("Leaf: %d", leafIdx);
 							}
+							else {
+								ImGui::Text("Pseudo ID: %d", map->get_leaf(localCamera, i));
+							}
 							ImGui::Text("Parent Node: %d (child %d)",
 								nodeBranch.size() ? nodeBranch[nodeBranch.size() - 1] : headNode,
 								childIdx);

src/editor/Renderer.cpp

@@ -14,6 +14,7 @@
 #include <fstream>
 #include "globals.h"
 #include "NavMesh.h"
+#include "LeafNavMesh.h"
 #include <algorithm>
 #include "BspMerger.h"
 
@@ -453,6 +454,71 @@ void Renderer::renderLoop() {
 				}
 			}
 
+			if (debugLeafNavMesh) {
+				glLineWidth(1);
+
+				int leafIdx = mapRenderers[0]->map->get_leaf(cameraOrigin, 3);
+				int leafNavIdx = MAX_NAV_LEAVES;
+
+				if (leafIdx >= 0 && leafIdx < MAX_MAP_CLIPNODE_LEAVES) {
+					leafNavIdx = debugLeafNavMesh->leafMap[leafIdx];
+				}
+
+				if (leafNavIdx < MAX_NAV_LEAVES) {
+					LeafNavNode& node = debugLeafNavMesh->nodes[leafNavIdx];
+					LeafMesh& leaf = debugLeafNavMesh->leaves[leafNavIdx];
+
+					drawBox(leaf.center, 2, COLOR4(0, 255, 0, 255));
+
+					std::string linkStr;
+
+					for (int i = 0; i < MAX_NAV_LEAF_LINKS; i++) {
+						LeafNavLink& link = node.links[i];
+						if (link.node == -1) {
+							break;
+						}
+						LeafMesh& linkLeaf = debugLeafNavMesh->leaves[link.node];
+						Polygon3D& linkArea = link.linkArea;
+
+						drawLine(leaf.center, linkArea.center, COLOR4(0, 255, 255, 255));
+						drawLine(linkArea.center, linkLeaf.center, COLOR4(0, 255, 255, 255));
+
+						for (int k = 0; k < linkArea.verts.size(); k++) {
+							drawBox(linkArea.verts[k], 1, COLOR4(255, 255, 0, 255));
+						}
+						drawBox(linkArea.center, 1, COLOR4(0, 255, 0, 255));
+						drawBox(linkLeaf.center, 2, COLOR4(0, 255, 255, 255));
+						linkStr += to_string(link.node) + " (" + to_string(linkArea.verts.size()) + "v), ";
+					}
+
+					//logf("Leaf node idx: %d, links: %s\n", leafNavIdx, linkStr.c_str());
+				}
+
+				glDisable(GL_DEPTH_TEST);
+
+				colorShader->pushMatrix(MAT_PROJECTION);
+				colorShader->pushMatrix(MAT_VIEW);
+				projection.ortho(0, windowWidth, windowHeight, 0, -1.0f, 1.0f);
+				view.loadIdentity();
+				colorShader->updateMatrixes();
+
+				Line2D edge(vec2(1000, 400), vec2(1400, 630));
+				drawLine2D(edge.start, edge.end, COLOR4(255, 0, 0, 255));
+
+				/*
+				double xpos, ypos;
+				glfwGetCursorPos(window, &xpos, &ypos);
+				vec2 mousepos = vec2(xpos, ypos);
+				drawBox2D(mousepos, 8, COLOR4(255, 0, 0, 255));
+				drawBox2D(edge.project(mousepos), 8, COLOR4(255, 0, 0, 255));
+				float dist = edge.distance(mousepos);
+				logf("dist: %f\n", edge.distance(mousepos));
+				*/
+
+				colorShader->popMatrix(MAT_PROJECTION);
+				colorShader->popMatrix(MAT_VIEW);
+			}
+
 			if (debugPoly.isValid) {
 				if (debugPoly.verts.size() > 1) {
 					vec3 v1 = debugPoly.verts[0];

src/editor/Renderer.h

@@ -14,6 +14,7 @@ class ShaderProgram;
 class PointEntRenderer;
 class Entity;
 class Bsp;
+class LeafNavMesh;
 
 enum transform_modes {
 	TRANSFORM_NONE = -1,
@@ -77,6 +78,7 @@ class Renderer {
 	Polygon3D debugPoly;
 	Polygon3D debugPoly2;
 	NavMesh* debugNavMesh = NULL;
+	LeafNavMesh* debugLeafNavMesh = NULL;
 	int debugNavPoly = -1;
 	vec3 debugTraceStart;
 	TraceResult debugTrace;