network UDP: transmit structural DNA to deal with version/platform differences.

pybullet: allow to specify shared memory key and hostname/port for UDP.

examples/SharedMemory/PhysicsDirect.cpp

@@ -23,6 +23,7 @@ struct PhysicsDirectInternalData
 {
 	DummyGUIHelper m_noGfx;
 
+	btAlignedObjectArray<char> m_serverDNA;
 	SharedMemoryCommand m_command;
 	SharedMemoryStatus m_serverStatus;
 	bool m_hasStatus;
@@ -83,6 +84,31 @@ bool PhysicsDirect::connect()
 {
 	bool connected = m_data->m_commandProcessor->connect();
 	m_data->m_commandProcessor->setGuiHelper(&m_data->m_noGfx);
+
+
+	//also request serialization data
+	{
+		SharedMemoryCommand command;
+		command.m_type = CMD_REQUEST_INTERNAL_DATA;
+		bool hasStatus = m_data->m_commandProcessor->processCommand(command, m_data->m_serverStatus, &m_data->m_bulletStreamDataServerToClient[0], SHARED_MEMORY_MAX_STREAM_CHUNK_SIZE);
+		if (hasStatus)
+		{
+			postProcessStatus(m_data->m_serverStatus);
+		}
+		else
+		{
+			int timeout = 1024 * 1024 * 1024;
+			while ((!hasStatus) && (timeout-- > 0))
+			{
+				const  SharedMemoryStatus* stat = processServerStatus();
+				if (stat)
+				{
+					hasStatus = true;
+				}
+			}
+		}
+	}
+
 	return connected;
 }
 
@@ -444,7 +470,14 @@ void PhysicsDirect::processBodyJointInfo(int bodyUniqueId, const SharedMemorySta
     bParse::btBulletFile bf(
         &m_data->m_bulletStreamDataServerToClient[0],
         serverCmd.m_numDataStreamBytes);
-    bf.setFileDNAisMemoryDNA();
+	if (m_data->m_serverDNA.size())
+	{
+		bf.setFileDNA(false, &m_data->m_serverDNA[0], m_data->m_serverDNA.size());
+	}
+	else
+	{
+		bf.setFileDNAisMemoryDNA();
+	}
     bf.parse(false);
 	
     BodyJointInfoCache2* bodyJoints = new BodyJointInfoCache2;
@@ -469,7 +502,8 @@ void PhysicsDirect::processBodyJointInfo(int bodyUniqueId, const SharedMemorySta
             addJointInfoFromMultiBodyData(mb,bodyJoints, m_data->m_verboseOutput);
         }
     }
-    if (bf.ok()) {
+    if (bf.ok()) 
+	{
         if (m_data->m_verboseOutput) 
         {
             b3Printf("Received robot description ok!\n");
@@ -484,6 +518,19 @@ void PhysicsDirect::postProcessStatus(const struct SharedMemoryStatus& serverCmd
 {
 	switch (serverCmd.m_type)
 	{
+	case CMD_REQUEST_INTERNAL_DATA_COMPLETED:
+	{
+		if (serverCmd.m_numDataStreamBytes)
+		{
+			int numStreamBytes = serverCmd.m_numDataStreamBytes;
+			m_data->m_serverDNA.resize(numStreamBytes);
+			for (int i = 0; i < numStreamBytes; i++)
+			{
+				m_data->m_serverDNA[i] = m_data->m_bulletStreamDataServerToClient[i];
+			}
+		}
+		break;
+	}
 	case CMD_RESET_SIMULATION_COMPLETED:
 	{
 		m_data->m_debugLinesFrom.clear();

examples/SharedMemory/PhysicsServerCommandProcessor.cpp

@@ -2178,6 +2178,28 @@ bool PhysicsServerCommandProcessor::processCommand(const struct SharedMemoryComm
                     break;
                 }
 
+				case CMD_REQUEST_INTERNAL_DATA:
+				{
+					//todo: also check version etc?
+
+					SharedMemoryStatus& serverCmd = serverStatusOut;
+					serverCmd.m_type = CMD_REQUEST_INTERNAL_DATA_FAILED;
+					hasStatus = true;
+					
+					int sz = btDefaultSerializer::getMemoryDnaSizeInBytes();
+					const char* memDna = btDefaultSerializer::getMemoryDna();
+					if (sz < bufferSizeInBytes)
+					{
+						for (int i = 0; i < bufferSizeInBytes; i++)
+						{
+							bufferServerToClient[i] = memDna[i];
+						}
+						serverCmd.m_type = CMD_REQUEST_INTERNAL_DATA_COMPLETED;
+						serverCmd.m_numDataStreamBytes = bufferSizeInBytes;
+					}
+
+					break;
+				};
 				case CMD_SEND_PHYSICS_SIMULATION_PARAMETERS:
 				{
 					if (clientCmd.m_updateFlags&SIM_PARAM_UPDATE_DELTA_TIME)

examples/SharedMemory/SharedMemoryPublic.h

@@ -21,6 +21,7 @@ enum EnumSharedMemoryClientCommand
         CMD_REQUEST_ACTUAL_STATE,
         CMD_REQUEST_DEBUG_LINES,
     CMD_REQUEST_BODY_INFO,
+	CMD_REQUEST_INTERNAL_DATA,
     CMD_STEP_FORWARD_SIMULATION,
     CMD_RESET_SIMULATION,
     CMD_PICK_BODY,
@@ -54,6 +55,8 @@ enum EnumSharedMemoryServerStatus
         CMD_SDF_LOADING_FAILED,
         CMD_URDF_LOADING_COMPLETED,
         CMD_URDF_LOADING_FAILED,
+		CMD_REQUEST_INTERNAL_DATA_COMPLETED,
+		CMD_REQUEST_INTERNAL_DATA_FAILED,
         CMD_BULLET_DATA_STREAM_RECEIVED_COMPLETED,
         CMD_BULLET_DATA_STREAM_RECEIVED_FAILED,
         CMD_BOX_COLLISION_SHAPE_CREATION_COMPLETED,

examples/pybullet/pybullet.c

@@ -61,12 +61,45 @@ static PyObject* pybullet_connectPhysicsServer(PyObject* self, PyObject* args) {
 
   {
     int method = eCONNECT_GUI;
-    if (!PyArg_ParseTuple(args, "i", &method)) {
+	int key = SHARED_MEMORY_KEY;
-      PyErr_SetString(SpamError,
+	int port = 1234;
-                      "connectPhysicsServer expected argument  GUI, "
+	const char* hostName = "localhost";
-                      "DIRECT, SHARED_MEMORY or UDP");
+
-      return NULL;
+	int size = PySequence_Size(args);
-    }
+	if (size == 1)
+	{
+		if (!PyArg_ParseTuple(args, "i", &method)) {
+			PyErr_SetString(SpamError,
+				"connectPhysicsServer expected argument  GUI, "
+				"DIRECT, SHARED_MEMORY or UDP");
+			return NULL;
+		}
+	}
+
+	if (size == 2)
+	{
+		if (!PyArg_ParseTuple(args, "ii", &method, &key)) 
+		{
+			if (!PyArg_ParseTuple(args, "is", &method, &hostName))
+			{
+				PyErr_SetString(SpamError,
+					"connectPhysicsServer cannot parse second argument (either integer or string)");
+				return NULL;
+
+			}
+		}
+	}
+
+	if (size == 3)
+	{
+		if (!PyArg_ParseTuple(args, "isi", &method, &hostName, &port))
+		{
+			PyErr_SetString(SpamError,
+				"connectPhysicsServer 3 arguments: method, hostname, port");
+			return NULL;
+		}
+	}
+
 
     switch (method) {
       case eCONNECT_GUI: {
@@ -85,14 +118,14 @@ static PyObject* pybullet_connectPhysicsServer(PyObject* self, PyObject* args) {
         break;
       }
       case eCONNECT_SHARED_MEMORY: {
-        sm = b3ConnectSharedMemory(SHARED_MEMORY_KEY);
+        sm = b3ConnectSharedMemory(key);
         break;
       }
 	  case eCONNECT_UDP: 
 	{
 #ifdef BT_ENABLE_ENET
 
-		  sm = b3ConnectPhysicsUDP("localhost", 1234);
+		  sm = b3ConnectPhysicsUDP(hostName, port);
 #else
  		PyErr_SetString(SpamError, "UDP is not enabled in this pybullet build");
 		return NULL;

src/LinearMath/btSerializer.h

@@ -446,6 +446,26 @@ public:
 				btAlignedFree(m_dna);
 		}
 
+		static int getMemoryDnaSizeInBytes()
+		{
+			const bool VOID_IS_8 = ((sizeof(void*) == 8));
+
+			if (VOID_IS_8)
+			{
+				return sBulletDNAlen64;
+			}
+			return sBulletDNAlen;
+		}
+		static const char* getMemoryDna()
+		{
+			const bool VOID_IS_8 = ((sizeof(void*) == 8));
+			if (VOID_IS_8)
+			{
+				return (const char*)sBulletDNAstr64;
+			}
+			return (const char*)sBulletDNAstr;
+		}
+
 		void	insertHeader()
 		{
 			writeHeader(m_buffer);