fix ray test kF_FilterBackfaces and kF_KeepUnflippedNormal flags

add Demos/RaytestDemo to show/test rayTest
fix premake batch files

Demos/CMakeLists.txt

@@ -12,7 +12,7 @@ IF (USE_GLUT)
 			SET(SharedDemoSubdirs
 			OpenGL AllBulletDemos  ConvexDecompositionDemo
 			CcdPhysicsDemo ConstraintDemo SliderConstraintDemo GenericJointDemo Raytracer
-			RagdollDemo ForkLiftDemo BasicDemo VoronoiFractureDemo FractureDemo Box2dDemo BspDemo MovingConcaveDemo VehicleDemo
+			RagdollDemo ForkLiftDemo BasicDemo RaytestDemo VoronoiFractureDemo FractureDemo Box2dDemo BspDemo MovingConcaveDemo VehicleDemo
 			UserCollisionAlgorithm CharacterDemo SoftDemo 
 			CollisionInterfaceDemo ConcaveConvexcastDemo SimplexDemo DynamicControlDemo
 			ConvexHullDistance
@@ -41,6 +41,7 @@ ELSE (USE_GLUT)
 		SUBDIRS( 
 		OpenGL 
 		BasicDemo
+		RaytestDemo
 		FractureDemo
 		Benchmarks 
 		Box2dDemo 

Demos/RaytestDemo/CMakeLists.txt

@@ -0,0 +1,87 @@
+# This is basically the overall name of the project in Visual Studio this is the name of the Solution File
+
+
+# For every executable you have with a main method you should have an add_executable line below.
+# For every add executable line you should list every .cpp and .h file you have associated with that executable.  
+
+
+# This is the variable for Windows.  I use this to define the root of my directory structure.
+SET(GLUT_ROOT ${BULLET_PHYSICS_SOURCE_DIR}/Glut)
+
+# You shouldn't have to modify anything below this line 
+########################################################
+
+INCLUDE_DIRECTORIES(
+${BULLET_PHYSICS_SOURCE_DIR}/src ${BULLET_PHYSICS_SOURCE_DIR}/Demos/OpenGL 
+)
+
+
+
+IF (USE_GLUT)
+	LINK_LIBRARIES(
+	OpenGLSupport  BulletDynamics  BulletCollision LinearMath  ${GLUT_glut_LIBRARY} ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
+	)
+
+IF (WIN32)
+ADD_EXECUTABLE(AppRaytestDemo
+		main.cpp
+		RaytestDemo.cpp 
+		RaytestDemo.h
+		${BULLET_PHYSICS_SOURCE_DIR}/build/bullet.rc
+	)
+ELSE()
+	ADD_EXECUTABLE(AppBasicDemo
+		main.cpp
+		BasicDemo.cpp 
+		BasicDemo.h
+	)
+ENDIF()
+
+
+
+
+	IF (WIN32)
+		IF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
+			IF (CMAKE_CL_64)
+				ADD_CUSTOM_COMMAND(
+					TARGET AppRaytestDemo
+					POST_BUILD
+					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/glut64.dll ${CMAKE_CURRENT_BINARY_DIR}
+				)
+			ELSE(CMAKE_CL_64)
+				ADD_CUSTOM_COMMAND(
+					TARGET AppRaytestDemo
+					POST_BUILD
+#		  		COMMAND copy /Y ${BULLET_PHYSICS_SOURCE_DIR}/GLUT32.DLL ${CMAKE_CURRENT_BINARY_DIR}
+					COMMAND ${CMAKE_COMMAND} ARGS -E copy_if_different ${BULLET_PHYSICS_SOURCE_DIR}/GLUT32.DLL ${CMAKE_CURRENT_BINARY_DIR}
+				)
+			ENDIF(CMAKE_CL_64)
+		ENDIF (NOT INTERNAL_CREATE_DISTRIBUTABLE_MSVC_PROJECTFILES)
+
+	ENDIF(WIN32)
+ELSE (USE_GLUT)
+
+ 
+
+	LINK_LIBRARIES(
+	OpenGLSupport  BulletDynamics  BulletCollision LinearMath  ${OPENGL_gl_LIBRARY} ${OPENGL_glu_LIBRARY}
+	)
+
+
+	ADD_EXECUTABLE(AppRaytestDemo
+		WIN32
+		../OpenGL/Win32AppMain.cpp
+		Win32BasicDemo.cpp
+		RaytestDemo.cpp 
+		RaytestDemo.h
+		${BULLET_PHYSICS_SOURCE_DIR}/build/bullet.rc
+	)
+	
+	
+ENDIF (USE_GLUT)
+
+IF (INTERNAL_ADD_POSTFIX_EXECUTABLE_NAMES)
+			SET_TARGET_PROPERTIES(AppRaytestDemo PROPERTIES  DEBUG_POSTFIX "_Debug")
+			SET_TARGET_PROPERTIES(AppRaytestDemo PROPERTIES  MINSIZEREL_POSTFIX "_MinsizeRel")
+			SET_TARGET_PROPERTIES(AppRaytestDemo PROPERTIES  RELWITHDEBINFO_POSTFIX "_RelWithDebugInfo")
+ENDIF(INTERNAL_ADD_POSTFIX_EXECUTABLE_NAMES)

Demos/RaytestDemo/Makefile.am

@@ -0,0 +1,5 @@
+noinst_PROGRAMS=BasicDemo
+
+BasicDemo_SOURCES=BasicDemo.cpp BasicDemo.h main.cpp
+BasicDemo_CXXFLAGS=-I@top_builddir@/src -I@top_builddir@/Demos/OpenGL $(CXXFLAGS)
+BasicDemo_LDADD=-L../OpenGL -lbulletopenglsupport -L../../src -lBulletDynamics -lBulletCollision -lLinearMath @opengl_LIBS@

Demos/RaytestDemo/RaytestDemo.cpp

@@ -0,0 +1,322 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+
+
+#include "RaytestDemo.h"
+#include "GlutStuff.h"
+///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
+#include "btBulletDynamicsCommon.h"
+#include "BulletCollision/NarrowPhaseCollision/btRaycastCallback.h"
+
+#include <stdio.h> //printf debugging
+#include "GLDebugDrawer.h"
+static GLDebugDrawer sDebugDraw;
+
+
+
+void RaytestDemo::castRays() 
+{
+	
+	static float up = 0.f;
+	static float dir = 1.f;
+	//add some simple animation
+	if (!m_idle)
+	{
+		up+=0.01*dir;
+
+		if (btFabs(up)>2)
+		{
+			dir*=-1.f;
+		}
+
+		btTransform tr = m_dynamicsWorld->getCollisionObjectArray()[1]->getWorldTransform();
+		static float angle = 0.f;
+		angle+=0.01f;
+		tr.setRotation(btQuaternion(btVector3(0,1,0),angle));
+		m_dynamicsWorld->getCollisionObjectArray()[1]->setWorldTransform(tr);
+	}
+
+	
+	///step the simulation
+	if (m_dynamicsWorld)
+	{
+		
+		m_dynamicsWorld->updateAabbs();
+		m_dynamicsWorld->computeOverlappingPairs();
+		
+		btVector3 red(1,0,0);
+		btVector3 blue(0,0,1);
+
+		///all hits
+		{
+			btVector3 from(-30,1+up,0);
+			btVector3 to(30,1,0);
+			sDebugDraw.drawLine(from,to,btVector4(0,0,0,1));
+			btCollisionWorld::AllHitsRayResultCallback allResults(from,to);
+			allResults.m_flags |= btTriangleRaycastCallback::kF_KeepUnflippedNormal;
+			m_dynamicsWorld->rayTest(from,to,allResults);
+
+			for (int i=0;i<allResults.m_hitFractions.size();i++)
+			{
+				btVector3 p = from.lerp(to,allResults.m_hitFractions[i]);
+				sDebugDraw.drawSphere(p,0.1,red);
+			}
+		}
+
+		///first hit
+		{
+			btVector3 from(-30,1.2,0);
+			btVector3 to(30,1.2,0);
+			sDebugDraw.drawLine(from,to,btVector4(0,0,1,1));
+
+			btCollisionWorld::ClosestRayResultCallback	closestResults(from,to);
+			closestResults.m_flags |= btTriangleRaycastCallback::kF_FilterBackfaces;
+			m_dynamicsWorld->rayTest(from,to,closestResults);
+
+
+			if (closestResults.hasHit())
+			{
+				
+				btVector3 p = from.lerp(to,closestResults.m_closestHitFraction);
+				sDebugDraw.drawSphere(p,0.1,blue);
+				sDebugDraw.drawLine(p,p+closestResults.m_hitNormalWorld,blue);
+
+			}
+		}
+	}
+
+}
+
+
+void RaytestDemo::clientMoveAndDisplay()
+{
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
+
+	castRays();
+	
+	if (m_dynamicsWorld)
+	{
+		float ms = getDeltaTimeMicroseconds();
+		m_dynamicsWorld->stepSimulation(ms / 1000000.f);
+
+		m_dynamicsWorld->debugDrawWorld();
+	}
+
+
+		
+	renderme(); 
+
+	glFlush();
+
+	swapBuffers();
+
+}
+
+
+
+void RaytestDemo::displayCallback(void) {
+
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); 
+	
+	castRays();
+
+	renderme();
+
+	//optional but useful: debug drawing to detect problems
+	if (m_dynamicsWorld)
+		m_dynamicsWorld->debugDrawWorld();
+
+	glFlush();
+	swapBuffers();
+}
+
+
+
+
+
+void	RaytestDemo::initPhysics()
+{
+	m_ele = 10;
+	m_azi = 75;
+
+	setTexturing(true);
+	setShadows(true);
+
+	setCameraDistance(btScalar(20.));
+
+	///collision configuration contains default setup for memory, collision setup
+	m_collisionConfiguration = new btDefaultCollisionConfiguration();
+	//m_collisionConfiguration->setConvexConvexMultipointIterations();
+
+	///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
+	m_dispatcher = new	btCollisionDispatcher(m_collisionConfiguration);
+
+	m_broadphase = new btDbvtBroadphase();
+
+	///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
+	btSequentialImpulseConstraintSolver* sol = new btSequentialImpulseConstraintSolver;
+	m_solver = sol;
+
+	m_dynamicsWorld = new btDiscreteDynamicsWorld(m_dispatcher,m_broadphase,m_solver,m_collisionConfiguration);
+	m_dynamicsWorld ->setDebugDrawer(&sDebugDraw);
+	m_dynamicsWorld->setGravity(btVector3(0,-10,0));
+
+	///create a few basic rigid bodies
+	btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(50.),btScalar(50.),btScalar(50.)));
+//	btCollisionShape* groundShape = new btStaticPlaneShape(btVector3(0,1,0),50);
+	
+	m_collisionShapes.push_back(groundShape);
+
+	btTransform groundTransform;
+	groundTransform.setIdentity();
+	groundTransform.setOrigin(btVector3(0,-50,0));
+
+	//We can also use DemoApplication::localCreateRigidBody, but for clarity it is provided here:
+	{
+		btScalar mass(0.);
+
+		//rigidbody is dynamic if and only if mass is non zero, otherwise static
+		bool isDynamic = (mass != 0.f);
+
+		btVector3 localInertia(0,0,0);
+		if (isDynamic)
+			groundShape->calculateLocalInertia(mass,localInertia);
+
+		//using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
+		btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
+		btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,groundShape,localInertia);
+		btRigidBody* body = new btRigidBody(rbInfo);
+
+		//add the body to the dynamics world
+		m_dynamicsWorld->addRigidBody(body);
+	}
+
+
+	{
+		btVector3 convexPoints[]={ btVector3(-1,-1,-1),btVector3(-1,-1,1),btVector3(-1,1,1),btVector3(-1,1,-1),
+			btVector3(2,0,0)};
+
+		btVector3 quad[] = {
+			btVector3(0,1,-1),
+			btVector3(0,1,1),
+			btVector3(0,-1,1),
+			btVector3(0,-1,-1)};
+
+		btTriangleMesh* mesh = new btTriangleMesh();
+		mesh->addTriangle(quad[0],quad[1],quad[2],true);
+		mesh->addTriangle(quad[0],quad[2],quad[3],true);
+
+		btBvhTriangleMeshShape* trimesh = new btBvhTriangleMeshShape(mesh,true,true);
+
+#define NUM_SHAPES 6
+			btCollisionShape* colShapes[NUM_SHAPES] = {
+				trimesh,
+				new btConvexHullShape(&convexPoints[0].getX(),sizeof(convexPoints)/sizeof(btVector3),sizeof(btVector3)),
+				new btSphereShape(1),
+				new btCapsuleShape(0.2,1),
+				new btCylinderShape(btVector3(0.2,1,0.2)),
+				new btBoxShape(btVector3(1,1,1))
+			};
+
+		for (int i=0;i<NUM_SHAPES;i++)
+			m_collisionShapes.push_back(colShapes[i]);
+
+		for (int i=0;i<6;i++)
+		{
+			//create a few dynamic rigidbodies
+			// Re-using the same collision is better for memory usage and performance
+
+	
+
+			/// Create Dynamic Objects
+			btTransform startTransform;
+			startTransform.setIdentity();
+			startTransform.setOrigin(btVector3((i-3)*5,1,0));
+
+
+			btScalar	mass(1.f);
+
+			if (!i)
+				mass=0.f;
+
+			//rigidbody is dynamic if and only if mass is non zero, otherwise static
+			bool isDynamic = (mass != 0.f);
+
+			btVector3 localInertia(0,0,0);
+			btCollisionShape* colShape = colShapes[i%NUM_SHAPES];
+			if (isDynamic)
+				colShape->calculateLocalInertia(mass,localInertia);
+
+			btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,0,colShape,localInertia);
+			rbInfo.m_startWorldTransform = startTransform;
+			btRigidBody* body = new btRigidBody(rbInfo);
+		
+			m_dynamicsWorld->addRigidBody(body);
+	
+		}
+
+	}
+}
+void	RaytestDemo::clientResetScene()
+{
+	exitPhysics();
+	initPhysics();
+}
+	
+
+void	RaytestDemo::exitPhysics()
+{
+
+	//cleanup in the reverse order of creation/initialization
+
+	//remove the rigidbodies from the dynamics world and delete them
+	int i;
+	for (i=m_dynamicsWorld->getNumCollisionObjects()-1; i>=0 ;i--)
+	{
+		btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i];
+		btRigidBody* body = btRigidBody::upcast(obj);
+		if (body && body->getMotionState())
+		{
+			delete body->getMotionState();
+		}
+		m_dynamicsWorld->removeCollisionObject( obj );
+		delete obj;
+	}
+
+	//delete collision shapes
+	for (int j=0;j<m_collisionShapes.size();j++)
+	{
+		btCollisionShape* shape = m_collisionShapes[j];
+		delete shape;
+	}
+	m_collisionShapes.clear();
+
+	delete m_dynamicsWorld;
+	
+	delete m_solver;
+	
+	delete m_broadphase;
+	
+	delete m_dispatcher;
+
+	delete m_collisionConfiguration;
+
+	
+}
+
+
+
+

Demos/RaytestDemo/RaytestDemo.h

@@ -0,0 +1,82 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+#ifndef BT_RAYTEST_DEMO_H
+#define BT_RAYTEST_DEMO_H
+
+#ifdef _WINDOWS
+#include "Win32DemoApplication.h"
+#define PlatformDemoApplication Win32DemoApplication
+#else
+#include "GlutDemoApplication.h"
+#define PlatformDemoApplication GlutDemoApplication
+#endif
+
+#include "LinearMath/btAlignedObjectArray.h"
+
+class btBroadphaseInterface;
+class btCollisionShape;
+class btOverlappingPairCache;
+class btCollisionDispatcher;
+class btConstraintSolver;
+struct btCollisionAlgorithmCreateFunc;
+class btDefaultCollisionConfiguration;
+
+///RaytestDemo shows how to use the btCollisionWorld::rayTest feature
+
+class RaytestDemo : public PlatformDemoApplication
+{
+
+	//keep the collision shapes, for deletion/cleanup
+	btAlignedObjectArray<btCollisionShape*>	m_collisionShapes;
+
+	btBroadphaseInterface*	m_broadphase;
+
+	btCollisionDispatcher*	m_dispatcher;
+
+	btConstraintSolver*	m_solver;
+
+	btDefaultCollisionConfiguration* m_collisionConfiguration;
+
+	public:
+
+	RaytestDemo()
+	{
+	}
+	virtual ~RaytestDemo()
+	{
+		exitPhysics();
+	}
+	void	initPhysics();
+
+	void	exitPhysics();
+
+	virtual void clientMoveAndDisplay();
+	void castRays(); 
+	virtual void displayCallback();
+	virtual void	clientResetScene();
+	
+	static DemoApplication* Create()
+	{
+		RaytestDemo* demo = new RaytestDemo;
+		demo->myinit();
+		demo->initPhysics();
+		return demo;
+	}
+
+	
+};
+
+#endif //BT_RAYTEST_DEMO_H
+

Demos/RaytestDemo/Win32RaytestDemo.cpp

@@ -0,0 +1,25 @@
+#ifdef _WINDOWS
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "BasicDemo.h"
+
+///The 'createDemo' function is called from Bullet/Demos/OpenGL/Win32AppMain.cpp to instantiate this particular demo
+DemoApplication*	createDemo()
+{
+	return new BasicDemo();
+}
+
+#endif

Demos/RaytestDemo/main.cpp

@@ -0,0 +1,41 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2007 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "RaytestDemo.h"
+#include "GlutStuff.h"
+#include "btBulletDynamicsCommon.h"
+#include "LinearMath/btHashMap.h"
+
+
+
+
+	
+int main(int argc,char** argv)
+{
+
+	RaytestDemo ccdDemo;
+	ccdDemo.initPhysics();
+
+
+#ifdef CHECK_MEMORY_LEAKS
+	ccdDemo.exitPhysics();
+#else
+	return glutmain(argc, argv,1024,600,"Bullet Physics Demo. http://bulletphysics.org",&ccdDemo);
+#endif
+	
+	//default glut doesn't return from mainloop
+	return 0;
+}
+

Demos/premake4.lua

@@ -70,6 +70,7 @@ end
     "MultiMaterialDemo",
     "RagdollDemo",
     "Raytracer",
+    "RaytestDemo",
     "SimplexDemo",
     "SliderConstraintDemo",
     "TerrainDemo",

build/vs2008.bat

@@ -4,7 +4,7 @@ rem premake4 --no-pedemos vs2008
 rem premake4 --no-bulletlibs --no-pelibs vs2008
 rem premake4 --with-nacl vs2008
 
-premake4 --with-demos vs2008
+premake4  vs2008
 
 
 pause

build/vs2010.bat

@@ -1,4 +1,4 @@
 
-premake4 --with-demos vs2010
+premake4  vs2010
 
 pause

src/BulletCollision/CollisionDispatch/btCollisionWorld.cpp

@@ -208,6 +208,11 @@ void	btCollisionWorld::updateAabbs()
 }
 
 
+void	btCollisionWorld::computeOverlappingPairs()
+{
+	BT_PROFILE("calculateOverlappingPairs");
+	m_broadphasePairCache->calculateOverlappingPairs(m_dispatcher1);
+}
 
 void	btCollisionWorld::performDiscreteCollisionDetection()
 {
@@ -217,11 +222,7 @@ void	btCollisionWorld::performDiscreteCollisionDetection()
 
 	updateAabbs();
 
-	{
-		BT_PROFILE("calculateOverlappingPairs");
-		m_broadphasePairCache->calculateOverlappingPairs(m_dispatcher1);
-	}
-
+	computeOverlappingPairs();
 
 	btDispatcher* dispatcher = getDispatcher();
 	{
@@ -456,6 +457,7 @@ void	btCollisionWorld::rayTestSingleInternal(const btTransform& rayFromTrans,con
 						: m_userCallback(user), m_i(i)
 					{ 
 						m_closestHitFraction = m_userCallback->m_closestHitFraction;
+						m_flags = m_userCallback->m_flags;
 					}
 					virtual bool needsCollision(btBroadphaseProxy* p) const
 					{

src/BulletCollision/CollisionDispatch/btCollisionWorld.h

@@ -145,6 +145,11 @@ public:
 
 	virtual void	updateAabbs();
 
+	///the computeOverlappingPairs is usually already called by performDiscreteCollisionDetection (or stepSimulation)
+	///it can be useful to use if you perform ray tests without collision detection/simulation
+	virtual void	computeOverlappingPairs();
+
+	
 	virtual void	setDebugDrawer(btIDebugDraw*	debugDrawer)
 	{
 			m_debugDrawer = debugDrawer;
@@ -198,7 +203,7 @@ public:
 		const btCollisionObject*		m_collisionObject;
 		short int	m_collisionFilterGroup;
 		short int	m_collisionFilterMask;
-      //@BP Mod - Custom flags, currently used to enable backface culling on tri-meshes, see btRaycastCallback
+		//@BP Mod - Custom flags, currently used to enable backface culling on tri-meshes, see btRaycastCallback.h. Apply any of the EFlags defined there on m_flags here to invoke.
 		unsigned int m_flags;
 
 		virtual ~RayResultCallback()

src/BulletCollision/NarrowPhaseCollision/btRaycastCallback.cpp

@@ -57,13 +57,14 @@ void btTriangleRaycastCallback::processTriangle(btVector3* triangle,int partId,
 	{
 		return ; // same sign
 	}
-   //@BP Mod - Backface filtering
-   if (((m_flags & kF_FilterBackfaces) != 0) && (dist_a > btScalar(0.0)))
+
+	if (((m_flags & kF_FilterBackfaces) != 0) && (dist_a <= btScalar(0.0)))
 	{
 		// Backface, skip check
 		return;
 	}
 
+	
 	const btScalar proj_length=dist_a-dist_b;
 	const btScalar distance = (dist_a)/(proj_length);
 	// Now we have the intersection point on the plane, we'll see if it's inside the triangle
@@ -102,7 +103,7 @@ void btTriangleRaycastCallback::processTriangle(btVector3* triangle,int partId,
 				      triangleNormal.normalize();
 
 					 //@BP Mod - Allow for unflipped normal when raycasting against backfaces
-                  if (((m_flags & kF_KeepUnflippedNormal) != 0) || (dist_a <= btScalar(0.0)))
+						if (((m_flags & kF_KeepUnflippedNormal) == 0) && (dist_a <= btScalar(0.0)))
 						{
 							m_hitFraction = reportHit(-triangleNormal,distance,partId,triangleIndex);
 						}