Recast: expose option to ignore input triangle winding order to user interface

Disabled by default.

src/naveditor/Editor.cpp

@@ -142,6 +142,7 @@ Editor::Editor() :
 	m_navMeshDrawFlags(
 		DU_DRAW_DETOURMESH_OFFMESHCONS|DU_DRAW_DETOURMESH_WITH_CLOSED_LIST|
 		DU_DRAW_DETOURMESH_POLY_FACES|DU_DRAW_DETOURMESH_POLY_BOUNDS_OUTER|DU_DRAW_DETOURMESH_ALPHA),
+	m_ignoreWindingOrder(false),
 	m_filterLowHangingObstacles(true),
 	m_filterLedgeSpans(true),
 	m_filterWalkableLowHeightSpans(true),
@@ -331,6 +332,8 @@ void Editor::handleCommonSettings()
 		snprintf(text, 64, "Voxels: %d x %d", gw, gh);
 		ImGui::Text(text);
 	}
+
+	ImGui::Checkbox("Ignore Winding Order", &m_ignoreWindingOrder);
 	
 	ImGui::Separator();
 	ImGui::Text("Agent");

src/naveditor/Editor_SoloMesh.cpp

@@ -189,6 +189,7 @@ bool Editor_SoloMesh::handleBuild()
 	m_cfg.maxVertsPerPoly = (int)m_vertsPerPoly;
 	m_cfg.detailSampleDist = m_detailSampleDist < 0.9f ? 0 : m_cellSize * m_detailSampleDist;
 	m_cfg.detailSampleMaxError = m_cellHeight * m_detailSampleMaxError;
+	m_cfg.ignoreWindingOrder = m_ignoreWindingOrder;
 	
 	// Set the area where the navigation will be build.
 	// Here the bounds of the input mesh are used, but the
@@ -238,7 +239,7 @@ bool Editor_SoloMesh::handleBuild()
 	// If your input data is multiple meshes, you can transform them here, calculate
 	// the are type for each of the meshes and rasterize them.
 	memset(m_triareas, 0, ntris*sizeof(unsigned char));
-	rcMarkWalkableTriangles(m_ctx, m_cfg.walkableSlopeAngle, verts, nverts, tris, ntris, m_triareas, true);
+	rcMarkWalkableTriangles(m_ctx, m_cfg.walkableSlopeAngle, verts, nverts, tris, ntris, m_triareas, m_cfg.ignoreWindingOrder);
 	if (!rcRasterizeTriangles(m_ctx, verts, nverts, tris, m_triareas, ntris, *m_solid, m_cfg.walkableClimb))
 	{
 		m_ctx->log(RC_LOG_ERROR, "buildNavigation: Could not rasterize triangles.");

src/naveditor/Editor_TempObstacles.cpp

@@ -253,6 +253,8 @@ int Editor_TempObstacles::rasterizeTileLayers(
 	tcfg.bmin[1] -= tcfg.borderSize*tcfg.cs;
 	tcfg.bmax[0] += tcfg.borderSize*tcfg.cs;
 	tcfg.bmax[1] += tcfg.borderSize*tcfg.cs;
+
+	tcfg.ignoreWindingOrder = m_ignoreWindingOrder;
 	
 	// Allocate voxel heightfield where we rasterize our input data to.
 	rc.solid = rcAllocHeightfield();
@@ -298,7 +300,7 @@ int Editor_TempObstacles::rasterizeTileLayers(
 		
 		memset(rc.triareas, 0, ntris*sizeof(unsigned char));
 		rcMarkWalkableTriangles(m_ctx, tcfg.walkableSlopeAngle,
-								verts, nverts, tris, ntris, rc.triareas, false);
+								verts, nverts, tris, ntris, rc.triareas, tcfg.ignoreWindingOrder);
 		
 		if (!rcRasterizeTriangles(m_ctx, verts, nverts, tris, rc.triareas, ntris, *rc.solid, tcfg.walkableClimb))
 			return 0;
@@ -319,7 +321,7 @@ int Editor_TempObstacles::rasterizeTileLayers(
 
 			memset(rc.triareas, 0, ntris * sizeof(unsigned char));
 			rcMarkWalkableTriangles(m_ctx, tcfg.walkableSlopeAngle,
-				verts, nverts, tris, ntris, rc.triareas, true);
+				verts, nverts, tris, ntris, rc.triareas, tcfg.ignoreWindingOrder);
 
 			if (!rcRasterizeTriangles(m_ctx, verts, nverts, tris, rc.triareas, ntris, *rc.solid, tcfg.walkableClimb))
 				return 0;

src/naveditor/Editor_TileMesh.cpp

@@ -966,6 +966,7 @@ unsigned char* Editor_TileMesh::buildTileMesh(const int tx, const int ty, const
 	m_cfg.height = m_cfg.tileSize + m_cfg.borderSize*2;
 	m_cfg.detailSampleDist = m_detailSampleDist < 0.9f ? 0 : m_cellSize * m_detailSampleDist;
 	m_cfg.detailSampleMaxError = m_cellHeight * m_detailSampleMaxError;
+	m_cfg.ignoreWindingOrder = m_ignoreWindingOrder;
 	
 	// Expand the heighfield bounding box by border size to find the extents of geometry we need to build this tile.
 	//
@@ -1051,7 +1052,7 @@ unsigned char* Editor_TileMesh::buildTileMesh(const int tx, const int ty, const
 		
 		memset(m_triareas, 0, nctris*sizeof(unsigned char));
 		rcMarkWalkableTriangles(m_ctx, m_cfg.walkableSlopeAngle,
-								verts, nverts, ctris, nctris, m_triareas, false);
+								verts, nverts, ctris, nctris, m_triareas, m_cfg.ignoreWindingOrder);
 		
 		if (!rcRasterizeTriangles(m_ctx, verts, nverts, ctris, m_triareas, nctris, *m_solid, m_cfg.walkableClimb))
 			return 0;
@@ -1075,7 +1076,7 @@ unsigned char* Editor_TileMesh::buildTileMesh(const int tx, const int ty, const
 
 			memset(m_triareas, 0, nctris * sizeof(unsigned char));
 			rcMarkWalkableTriangles(m_ctx, m_cfg.walkableSlopeAngle,
-				verts, nverts, ctris, nctris, m_triareas, true);
+				verts, nverts, ctris, nctris, m_triareas, m_cfg.ignoreWindingOrder);
 
 			if (!rcRasterizeTriangles(m_ctx, verts, nverts, ctris, m_triareas, nctris, *m_solid, m_cfg.walkableClimb))
 				return 0;

src/naveditor/include/Editor.h

@@ -236,6 +236,7 @@ protected:
 	class dtNavMeshQuery* m_navQuery;
 	class dtCrowd* m_crowd;
 
+	bool m_ignoreWindingOrder;
 	bool m_filterLowHangingObstacles;
 	bool m_filterLedgeSpans;
 	bool m_filterWalkableLowHeightSpans;

src/thirdparty/recast/Recast/Include/Recast.h

@@ -274,6 +274,10 @@ struct rcConfig
 	/// The maximum distance the detail mesh surface should deviate from heightfield
 	/// data. (For height detail only.) [Limit: >=0] [Units: wu] 
 	float detailSampleMaxError;
+
+	/// Whether to ignore the winding order of the input geometry's triangles. If set, backwards
+	/// facing triangles will still be considered walkable if they meet all other criteria.
+	bool ignoreWindingOrder;
 };
 
 /// Defines the number of bits allocated to rcSpan::smin and rcSpan::smax.