Merge remote-tracking branch 'bp/master'

examples/SharedMemory/PhysicsClientC_API.cpp

@@ -1208,46 +1208,71 @@ int	b3GetNumJoints(b3PhysicsClientHandle physClient, int bodyId)
 	return cl->getNumJoints(bodyId);
 }
 
-
 int	b3GetJointInfo(b3PhysicsClientHandle physClient, int bodyIndex, int jointIndex, struct b3JointInfo* info)
 {
 	PhysicsClient* cl = (PhysicsClient* ) physClient;
 	return cl->getJointInfo(bodyIndex, jointIndex, *info);
 }
 
-b3SharedMemoryCommandHandle b3InitResetDynamicInfo(b3PhysicsClientHandle physClient)
+b3SharedMemoryCommandHandle b3GetDynamicsInfoCommandInit(b3PhysicsClientHandle physClient, int bodyUniqueId, int linkIndex)
 {
 	PhysicsClient* cl = (PhysicsClient* ) physClient;
 	b3Assert(cl);
 	b3Assert(cl->canSubmitCommand());
 	struct SharedMemoryCommand* command = cl->getAvailableSharedMemoryCommand();
 	b3Assert(command);
-	command->m_type = CMD_RESET_DYNAMIC_INFO;
+	command->m_type = CMD_GET_DYNAMICS_INFO;
+	command->m_getDynamicsInfoArgs.m_bodyUniqueId = bodyUniqueId;
+	command->m_getDynamicsInfoArgs.m_linkIndex = linkIndex;
+	return (b3SharedMemoryCommandHandle) command;
+}
+
+int b3GetDynamicsInfo(b3SharedMemoryStatusHandle statusHandle, struct b3DynamicsInfo* info)
+{
+	const SharedMemoryStatus* status = (const SharedMemoryStatus* ) statusHandle;
+	const b3DynamicsInfo &dynamicsInfo = status->m_dynamicsInfo;
+	btAssert(status->m_type == CMD_GET_DYNAMICS_INFO);
+	if (status->m_type != CMD_GET_DYNAMICS_INFO_COMPLETED)
+		return false;
+
+	info->m_mass = dynamicsInfo.m_mass;
+	info->m_lateralFrictionCoeff = dynamicsInfo.m_lateralFrictionCoeff;
+	return true;
+}
+
+b3SharedMemoryCommandHandle b3InitChangeDynamicsInfo(b3PhysicsClientHandle physClient)
+{
+	PhysicsClient* cl = (PhysicsClient* ) physClient;
+	b3Assert(cl);
+	b3Assert(cl->canSubmitCommand());
+	struct SharedMemoryCommand* command = cl->getAvailableSharedMemoryCommand();
+	b3Assert(command);
+	command->m_type = CMD_CHANGE_DYNAMICS_INFO;
 	command->m_updateFlags = 0;
 	
 	return (b3SharedMemoryCommandHandle) command;
 }
 
-int b3ResetDynamicInfoSetMass(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double mass)
+int b3ChangeDynamicsInfoSetMass(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double mass)
 {
 	struct SharedMemoryCommand* command = (struct SharedMemoryCommand*) commandHandle;
-	b3Assert(command->m_type == CMD_RESET_DYNAMIC_INFO);
+	b3Assert(command->m_type == CMD_CHANGE_DYNAMICS_INFO);
 	b3Assert(mass > 0);
-	command->m_resetDynamicInfoArgs.m_bodyUniqueId = bodyUniqueId;
+	command->m_changeDynamicsInfoArgs.m_bodyUniqueId = bodyUniqueId;
-	command->m_resetDynamicInfoArgs.m_linkIndex = linkIndex;
+	command->m_changeDynamicsInfoArgs.m_linkIndex = linkIndex;
-	command->m_resetDynamicInfoArgs.m_mass = mass;
+	command->m_changeDynamicsInfoArgs.m_mass = mass;
-	command->m_updateFlags |= RESET_DYNAMIC_INFO_SET_MASS;
+	command->m_updateFlags |= CHANGE_DYNAMICS_INFO_SET_MASS;
 	return 0;
 }
 
-int b3ResetDynamicInfoSetLateralFriction(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double lateralFriction)
+int b3ChangeDynamicsInfoSetLateralFriction(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double lateralFriction)
 {
 	struct SharedMemoryCommand* command = (struct SharedMemoryCommand*) commandHandle;
-	b3Assert(command->m_type == CMD_RESET_DYNAMIC_INFO);
+	b3Assert(command->m_type == CMD_CHANGE_DYNAMICS_INFO);
-	command->m_resetDynamicInfoArgs.m_bodyUniqueId = bodyUniqueId;
+	command->m_changeDynamicsInfoArgs.m_bodyUniqueId = bodyUniqueId;
-	command->m_resetDynamicInfoArgs.m_linkIndex = linkIndex;
+	command->m_changeDynamicsInfoArgs.m_linkIndex = linkIndex;
-	command->m_resetDynamicInfoArgs.m_lateralFriction = lateralFriction;
+	command->m_changeDynamicsInfoArgs.m_lateralFriction = lateralFriction;
-	command->m_updateFlags |= RESET_DYNAMIC_INFO_SET_LATERAL_FRICTION;
+	command->m_updateFlags |= CHANGE_DYNAMICS_INFO_SET_LATERAL_FRICTION;
 	return 0;
 }
 

examples/SharedMemory/PhysicsClientC_API.h

@@ -77,12 +77,13 @@ int	b3GetNumJoints(b3PhysicsClientHandle physClient, int bodyIndex);
 ///given a body and joint index, return the joint information. See b3JointInfo in SharedMemoryPublic.h
 int	b3GetJointInfo(b3PhysicsClientHandle physClient, int bodyIndex, int jointIndex, struct b3JointInfo* info);
 
-///given a body unique id and link index, return the dynamic information. See b3DynamicInfo in SharedMemoryPublic.h
+b3SharedMemoryCommandHandle b3GetDynamicsInfoCommandInit(b3PhysicsClientHandle physClient, int bodyUniqueId, int linkIndex);
-int b3GetDynamicInfo(b3PhysicsClientHandle physClient, int bodyUniqueId, int linkIndex, struct b3DynamicInfo* info);
+///given a body unique id and link index, return the dynamics information. See b3DynamicsInfo in SharedMemoryPublic.h
+int b3GetDynamicsInfo(b3SharedMemoryStatusHandle statusHandle, struct b3DynamicsInfo* info);
 	
-b3SharedMemoryCommandHandle b3InitResetDynamicInfo(b3PhysicsClientHandle physClient);
+b3SharedMemoryCommandHandle b3InitChangeDynamicsInfo(b3PhysicsClientHandle physClient);
-int b3ResetDynamicInfoSetMass(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double mass);
+int b3ChangeDynamicsInfoSetMass(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double mass);
-int b3ResetDynamicInfoSetLateralFriction(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double lateralFriction);
+int b3ChangeDynamicsInfoSetLateralFriction(b3SharedMemoryCommandHandle commandHandle, int bodyUniqueId, int linkIndex, double lateralFriction);
     
 b3SharedMemoryCommandHandle b3InitCreateUserConstraintCommand(b3PhysicsClientHandle physClient, int parentBodyIndex, int parentJointIndex, int childBodyIndex, int childJointIndex, struct b3JointInfo* info);
 

examples/SharedMemory/PhysicsClientExample.cpp

@@ -53,6 +53,9 @@ protected:
 	int m_canvasRGBIndex;
 	int m_canvasDepthIndex;
 	int m_canvasSegMaskIndex;
+
+	btScalar m_lightPos[3];
+	btScalar m_specularCoeff;
 	
 	void	createButton(const char* name, int id, bool isTrigger );
 
@@ -278,6 +281,12 @@ void PhysicsClientExample::prepareAndSubmitCommand(int commandId)
             
             b3RequestCameraImageSetCameraMatrices(commandHandle, viewMatrix,projectionMatrix);
 						b3RequestCameraImageSetPixelResolution(commandHandle, camVisualizerWidth,camVisualizerHeight);
+			float lightPos[3];
+			lightPos[0] = m_lightPos[0];
+			lightPos[1] = m_lightPos[1];
+			lightPos[2] = m_lightPos[2];
+			b3RequestCameraImageSetLightDirection(commandHandle, lightPos);
+			b3RequestCameraImageSetLightSpecularCoeff(commandHandle, m_specularCoeff);
 						b3SubmitClientCommand(m_physicsClientHandle, commandHandle);
 		        break;
         }
@@ -522,6 +531,7 @@ m_canvas(0),
 m_canvasRGBIndex(-1),
 m_canvasDepthIndex(-1),
 m_canvasSegMaskIndex(-1),
+m_specularCoeff(1.0),
 m_numMotors(0),
 m_options(options),
 m_isOptionalServerConnected(false)
@@ -660,6 +670,29 @@ void	PhysicsClientExample::createButtons()
 				}
 			}
 		}
+		
+		{
+			SliderParams sliderLightPosX("light source position x",&m_lightPos[0]);
+			SliderParams sliderLightPosY("light source position y",&m_lightPos[1]);
+			SliderParams sliderLightPosZ("light source position z",&m_lightPos[2]);
+			SliderParams sliderSpecularCoeff("specular coefficient",&m_specularCoeff);
+			sliderLightPosX.m_minVal=-1.5;
+			sliderLightPosX.m_maxVal=1.5;
+			sliderLightPosY.m_minVal=-1.5;
+			sliderLightPosY.m_maxVal=1.5;
+			sliderLightPosZ.m_minVal=-1.5;
+			sliderLightPosZ.m_maxVal=1.5;
+			sliderSpecularCoeff.m_minVal=0;
+			sliderSpecularCoeff.m_maxVal=5.0;
+			if (m_guiHelper && m_guiHelper->getParameterInterface())
+			{
+				m_guiHelper->getParameterInterface()->registerSliderFloatParameter(sliderLightPosX);
+				m_guiHelper->getParameterInterface()->registerSliderFloatParameter(sliderLightPosY);
+				m_guiHelper->getParameterInterface()->registerSliderFloatParameter(sliderLightPosZ);
+				m_guiHelper->getParameterInterface()->registerSliderFloatParameter(sliderSpecularCoeff);
+			}
+
+		}
     }
 }
 
@@ -684,6 +717,10 @@ void	PhysicsClientExample::initPhysics()
 
 	m_selectedBody = -1;
 	m_prevSelectedBody = -1;
+	
+	m_lightPos[0] = 1.0;
+	m_lightPos[1] = 1.0;
+	m_lightPos[2] = 1.0;
 
 	{
 		m_canvas = m_guiHelper->get2dCanvasInterface();

examples/SharedMemory/PhysicsClientSharedMemory.cpp

@@ -1039,6 +1039,15 @@ const SharedMemoryStatus* PhysicsClientSharedMemory::processServerStatus() {
 				b3Warning("Removing body failed");
 				break;
 			}
+			case CMD_GET_DYNAMICS_INFO_COMPLETED:
+			{
+				break;
+			}
+			case CMD_GET_DYNAMICS_INFO_FAILED:
+			{
+				b3Warning("Request dynamics info failed");
+				break;
+			}
             default: {
                 b3Error("Unknown server status %d\n", serverCmd.m_type);
                 btAssert(0);

examples/SharedMemory/PhysicsServerCommandProcessor.cpp

@@ -3898,15 +3898,15 @@ bool PhysicsServerCommandProcessor::processCommand(const struct SharedMemoryComm
 
 					break;
 				};
-				case CMD_RESET_DYNAMIC_INFO:
+				case CMD_CHANGE_DYNAMICS_INFO:
 				{
-					BT_PROFILE("CMD_RESET_DYNAMIC_INFO");
+					BT_PROFILE("CMD_CHANGE_DYNAMICS_INFO");
 					
-					if (clientCmd.m_updateFlags & RESET_DYNAMIC_INFO_SET_MASS)
+					if (clientCmd.m_updateFlags & CHANGE_DYNAMICS_INFO_SET_MASS)
 					{
-						int bodyUniqueId = clientCmd.m_resetDynamicInfoArgs.m_bodyUniqueId;
+						int bodyUniqueId = clientCmd.m_changeDynamicsInfoArgs.m_bodyUniqueId;
-						int linkIndex = clientCmd.m_resetDynamicInfoArgs.m_linkIndex;
+						int linkIndex = clientCmd.m_changeDynamicsInfoArgs.m_linkIndex;
-						double mass = clientCmd.m_resetDynamicInfoArgs.m_mass;
+						double mass = clientCmd.m_changeDynamicsInfoArgs.m_mass;
 						btAssert(bodyUniqueId >= 0);
 						btAssert(linkIndex >= -1);
 						
@@ -3925,11 +3925,11 @@ bool PhysicsServerCommandProcessor::processCommand(const struct SharedMemoryComm
 						}
 					}
 					
-					if (clientCmd.m_updateFlags & RESET_DYNAMIC_INFO_SET_LATERAL_FRICTION)
+					if (clientCmd.m_updateFlags & CHANGE_DYNAMICS_INFO_SET_LATERAL_FRICTION)
 					{
-						int bodyUniqueId = clientCmd.m_resetDynamicInfoArgs.m_bodyUniqueId;
+						int bodyUniqueId = clientCmd.m_changeDynamicsInfoArgs.m_bodyUniqueId;
-						int linkIndex = clientCmd.m_resetDynamicInfoArgs.m_linkIndex;
+						int linkIndex = clientCmd.m_changeDynamicsInfoArgs.m_linkIndex;
-						double lateralFriction = clientCmd.m_resetDynamicInfoArgs.m_lateralFriction;
+						double lateralFriction = clientCmd.m_changeDynamicsInfoArgs.m_lateralFriction;
 						btAssert(bodyUniqueId >= 0);
 						btAssert(linkIndex >= -1);
 						
@@ -3955,6 +3955,38 @@ bool PhysicsServerCommandProcessor::processCommand(const struct SharedMemoryComm
 					
 					break;
 				};
+				case CMD_GET_DYNAMICS_INFO:
+				{
+					int bodyUniqueId = clientCmd.m_getDynamicsInfoArgs.m_bodyUniqueId;
+					int linkIndex = clientCmd.m_getDynamicsInfoArgs.m_linkIndex;
+					InteralBodyData* body = m_data->m_bodyHandles.getHandle(bodyUniqueId);
+					if (body && body->m_multiBody)
+					{
+						SharedMemoryStatus& serverCmd = serverStatusOut;
+						serverCmd.m_type = CMD_GET_DYNAMICS_INFO_COMPLETED;
+						
+						btMultiBody* mb = body->m_multiBody;
+						if (linkIndex == -1)
+						{
+							serverCmd.m_dynamicsInfo.m_mass = mb->getBaseMass();
+							serverCmd.m_dynamicsInfo.m_lateralFrictionCoeff = mb->getBaseCollider()->getFriction();
+						}
+						else
+						{
+							serverCmd.m_dynamicsInfo.m_mass = mb->getLinkMass(linkIndex);
+							serverCmd.m_dynamicsInfo.m_lateralFrictionCoeff = mb->getLinkCollider(linkIndex)->getFriction();
+						}
+						hasStatus = true;
+					}
+					else
+					{
+						b3Warning("The dynamic info requested is not available");
+						SharedMemoryStatus& serverCmd = serverStatusOut;
+						serverCmd.m_type = CMD_GET_DYNAMICS_INFO_FAILED;
+						hasStatus = true;
+					}
+					break;
+				}
 				case CMD_SEND_PHYSICS_SIMULATION_PARAMETERS:
 				{
 					BT_PROFILE("CMD_SEND_PHYSICS_SIMULATION_PARAMETERS");

examples/SharedMemory/SharedMemoryCommands.h

@@ -106,14 +106,14 @@ struct BulletDataStreamArgs
 	char m_bodyName[MAX_FILENAME_LENGTH];
 };
 
-enum EnumResetDynamicInfoFlags
+enum EnumChangeDynamicsInfoFlags
 {
-	RESET_DYNAMIC_INFO_SET_MASS=1,
+	CHANGE_DYNAMICS_INFO_SET_MASS=1,
-	RESET_DYNAMIC_INFO_SET_COM=2,
+	CHANGE_DYNAMICS_INFO_SET_COM=2,
-	RESET_DYNAMIC_INFO_SET_LATERAL_FRICTION=4,
+	CHANGE_DYNAMICS_INFO_SET_LATERAL_FRICTION=4,
 };
 
-struct ResetDynamicInfoArgs
+struct ChangeDynamicsInfoArgs
 {
 	int m_bodyUniqueId;
 	int m_linkIndex;
@@ -122,6 +122,12 @@ struct ResetDynamicInfoArgs
 	double m_lateralFriction;
 };
 
+struct GetDynamicsInfoArgs
+{
+	int m_bodyUniqueId;
+	int m_linkIndex;
+};
+
 struct SetJointFeedbackArgs
 {
 	int m_bodyUniqueId;
@@ -738,7 +744,8 @@ struct SharedMemoryCommand
 		struct MjcfArgs	m_mjcfArguments;
 		struct FileArgs m_fileArguments;
 		struct SdfRequestInfoArgs m_sdfRequestInfoArgs;
-		struct ResetDynamicInfoArgs m_resetDynamicInfoArgs;
+		struct ChangeDynamicsInfoArgs m_changeDynamicsInfoArgs;
+		struct GetDynamicsInfoArgs m_getDynamicsInfoArgs;
 		struct InitPoseArgs m_initPoseArgs;
 		struct SendPhysicsSimulationParameters m_physSimParamArgs;
 		struct BulletDataStreamArgs	m_dataStreamArguments;
@@ -832,6 +839,7 @@ struct SharedMemoryStatus
 		struct StateLoggingResultArgs m_stateLoggingResultArgs;
 		struct b3OpenGLVisualizerCameraInfo m_visualizerCameraResultArgs;
 		struct b3ObjectArgs m_removeObjectArgs;
+		struct b3DynamicsInfo m_dynamicsInfo;
 	};
 };
 

examples/SharedMemory/SharedMemoryPublic.h

@@ -56,7 +56,8 @@ enum EnumSharedMemoryClientCommand
 	CMD_REQUEST_KEYBOARD_EVENTS_DATA,
 	CMD_REQUEST_OPENGL_VISUALIZER_CAMERA,
 	CMD_REMOVE_BODY,
-	CMD_RESET_DYNAMIC_INFO,
+	CMD_CHANGE_DYNAMICS_INFO,
+	CMD_GET_DYNAMICS_INFO,
 	CMD_PROFILE_TIMING,
     //don't go beyond this command!
     CMD_MAX_CLIENT_COMMANDS,
@@ -141,6 +142,8 @@ enum EnumSharedMemoryServerStatus
 		CMD_REQUEST_OPENGL_VISUALIZER_CAMERA_COMPLETED,
 		CMD_REMOVE_BODY_COMPLETED,
 		CMD_REMOVE_BODY_FAILED,
+		CMD_GET_DYNAMICS_INFO_COMPLETED,
+		CMD_GET_DYNAMICS_INFO_FAILED,
         //don't go beyond 'CMD_MAX_SERVER_COMMANDS!
         CMD_MAX_SERVER_COMMANDS
 };
@@ -220,10 +223,11 @@ struct b3BodyInfo
 	const char* m_bodyName; // for btRigidBody, it does not have a base, but can still have a body name from urdf
 };
 
-struct b3DynamicInfo
+struct b3DynamicsInfo
 {
 	double m_mass;
 	double m_localInertialPosition[3];
+	double m_lateralFrictionCoeff;
 };
 
 // copied from btMultiBodyLink.h

examples/TinyRenderer/model.cpp

@@ -167,8 +167,12 @@ Vec2f Model::uv(int iface, int nthvert) {
 }
 
 float Model::specular(Vec2f uvf) {
-    Vec2i uv(uvf[0]*specularmap_.get_width(), uvf[1]*specularmap_.get_height());
+	if (specularmap_.get_width() && specularmap_.get_height())
-    return specularmap_.get(uv[0], uv[1])[0]/1.f;
+	{
+		Vec2i uv(uvf[0]*specularmap_.get_width(), uvf[1]*specularmap_.get_height());
+		return specularmap_.get(uv[0], uv[1])[0]/1.f;
+	}
+	return 2.0;
 }
 
 Vec3f Model::normal(int iface, int nthvert) {

examples/pybullet/examples/reset_dynamic_info.py

@@ -3,18 +3,21 @@ import time
 import math
 
 p.connect(p.GUI)
-
+planeId = p.loadURDF(fileName="plane.urdf",baseOrientation=[0.25882,0,0,0.96593])
-p.loadURDF(fileName="plane.urdf",baseOrientation=[0.25882,0,0,0.96593])
 p.loadURDF(fileName="cube.urdf",baseOrientation=[0.25882,0,0,0.96593],basePosition=[0,0,2])
-p.loadURDF(fileName="cube.urdf",baseOrientation=[0,0,0,1],basePosition=[0,0,4])
+cubeId = p.loadURDF(fileName="cube.urdf",baseOrientation=[0,0,0,1],basePosition=[0,0,4])
-p.resetDynamicInfo(bodyUniqueId=2,linkIndex=-1,mass=0.1)
+p.changeDynamicsInfo(bodyUniqueId=2,linkIndex=-1,mass=0.1)
-#p.resetDynamicInfo(bodyUniqueId=2,linkIndex=-1,mass=100.0)
+#p.changeDynamicsInfo(bodyUniqueId=2,linkIndex=-1,mass=100.0)
 p.setGravity(0,0,-10)
 p.setRealTimeSimulation(0)
 t=0
 while 1:
 	t=t+1
 	if t > 400:
-		p.resetDynamicInfo(bodyUniqueId=0,linkIndex=-1,lateralFriction=0.01)
+		p.changeDynamicsInfo(bodyUniqueId=0,linkIndex=-1,lateralFriction=0.01)
+	mass1,frictionCoeff1=p.getDynamicsInfo(bodyUniqueId=planeId,linkIndex=-1)
+	mass2,frictionCoeff2=p.getDynamicsInfo(bodyUniqueId=cubeId,linkIndex=-1)
+	print mass1,frictionCoeff1
+	print mass2,frictionCoeff2
 	time.sleep(.01)
 	p.stepSimulation()

examples/pybullet/pybullet.c

@@ -604,7 +604,7 @@ static PyObject* pybullet_loadMJCF(PyObject* self, PyObject* args, PyObject* key
 	return pylist;
 }
 
-static PyObject* pybullet_resetDynamicInfo(PyObject* self, PyObject* args, PyObject* keywds)
+static PyObject* pybullet_changeDynamicsInfo(PyObject* self, PyObject* args, PyObject* keywds)
 {
 	int bodyUniqueId = -1;
 	int linkIndex = -2;
@@ -627,17 +627,17 @@ static PyObject* pybullet_resetDynamicInfo(PyObject* self, PyObject* args, PyObj
 	}
 	
 	{
-		b3SharedMemoryCommandHandle command = b3InitResetDynamicInfo(sm);
+		b3SharedMemoryCommandHandle command = b3InitChangeDynamicsInfo(sm);
 		b3SharedMemoryStatusHandle statusHandle;
 		
 		if (mass >= 0)
 		{
-			b3ResetDynamicInfoSetMass(command, bodyUniqueId, linkIndex, mass);
+			b3ChangeDynamicsInfoSetMass(command, bodyUniqueId, linkIndex, mass);
 		}
 		
 		if (lateralFriction >= 0)
 		{
-			b3ResetDynamicInfoSetLateralFriction(command, bodyUniqueId, linkIndex, lateralFriction);
+			b3ChangeDynamicsInfoSetLateralFriction(command, bodyUniqueId, linkIndex, lateralFriction);
 		}
 		
 		statusHandle = b3SubmitClientCommandAndWaitStatus(sm, command);
@@ -647,6 +647,63 @@ static PyObject* pybullet_resetDynamicInfo(PyObject* self, PyObject* args, PyObj
 	return Py_None;
 }
 
+static PyObject* pybullet_getDynamicsInfo(PyObject* self, PyObject* args, PyObject* keywds)
+{
+	{
+		int bodyUniqueId = -1;
+		int linkIndex = -2;
+		b3PhysicsClientHandle sm = 0;
+		
+		int physicsClientId = 0;
+		static char* kwlist[] = {"bodyUniqueId", "linkIndex", "physicsClientId", NULL};
+		if (!PyArg_ParseTupleAndKeywords(args, keywds, "ii|i", kwlist, &bodyUniqueId, &linkIndex, &physicsClientId))
+		{
+			return NULL;
+		}
+		sm = getPhysicsClient(physicsClientId);
+		if (sm == 0)
+		{
+			PyErr_SetString(SpamError, "Not connected to physics server.");
+			return NULL;
+		}
+		{
+			int status_type = 0;
+			b3SharedMemoryCommandHandle cmd_handle;
+			b3SharedMemoryStatusHandle status_handle;
+			
+			if (bodyUniqueId < 0)
+			{
+				PyErr_SetString(SpamError, "getDynamicsInfo failed; invalid bodyUniqueId");
+				return NULL;
+			}
+			if (linkIndex < -1)
+			{
+				PyErr_SetString(SpamError, "getDynamicsInfo failed; invalid linkIndex");
+				return NULL;
+			}
+			cmd_handle = b3GetDynamicsInfoCommandInit(sm, bodyUniqueId, linkIndex);
+			status_handle = b3SubmitClientCommandAndWaitStatus(sm, cmd_handle);
+			status_type = b3GetStatusType(status_handle);
+			if (status_type != CMD_GET_DYNAMICS_INFO_COMPLETED)
+			{
+				PyErr_SetString(SpamError, "getDynamicsInfo failed; invalid return status");
+				return NULL;
+			}
+			struct b3DynamicsInfo info;
+			if (b3GetDynamicsInfo(status_handle, &info))
+			{
+				PyObject* pyDynamicsInfo = PyTuple_New(2);
+				PyTuple_SetItem(pyDynamicsInfo, 0, PyFloat_FromDouble(info.m_mass));
+				PyTuple_SetItem(pyDynamicsInfo, 1, PyFloat_FromDouble(info.m_lateralFrictionCoeff));
+				return pyDynamicsInfo;
+			}
+		}
+	}
+	PyErr_SetString(SpamError, "Couldn't get dynamics info");
+	return NULL;
+}
+
+
 static PyObject* pybullet_setPhysicsEngineParameter(PyObject* self, PyObject* args, PyObject* keywds)
 {
 	double fixedTimeStep = -1;
@@ -5850,8 +5907,11 @@ static PyMethodDef SpamMethods[] = {
 	 "Reset the state (position, velocity etc) for a joint on a body "
 	 "instantaneously, not through physics simulation."},
 	
-	{"resetDynamicInfo", (PyCFunction)pybullet_resetDynamicInfo, METH_VARARGS | METH_KEYWORDS,
+	{"changeDynamicsInfo", (PyCFunction)pybullet_changeDynamicsInfo, METH_VARARGS | METH_KEYWORDS,
-	 "Reset dynamic information such as mass, lateral friction coefficient."},
+	 "change dynamics information such as mass, lateral friction coefficient."},
+	
+	{"getDynamicsInfo", (PyCFunction)pybullet_getDynamicsInfo, METH_VARARGS | METH_KEYWORDS,
+	 "Get dynamics information such as mass, lateral friction coefficient."},
 
 	{"setJointMotorControl", (PyCFunction)pybullet_setJointMotorControl, METH_VARARGS,
 	 "This (obsolete) method cannot select non-zero physicsClientId, use setJointMotorControl2 instead."