Add preliminary GRPC server for PyBullet and BulletRobotics.

Will add GRPC client and PyBullet GRPC server plugin.
Will cover most/all SharedMemoryCommand/SharedMemoryStatus messages.
Run the server, then test using the pybullet_client.py

examples/SharedMemory/grpc/ConvertGRPCBullet.cpp

@@ -0,0 +1,98 @@
+#include "ConvertGRPCBullet.h"
+#include "PhysicsClientC_API.h"
+#include "SharedMemoryCommands.h"
+#include <memory>
+#include <iostream>
+#include <string>
+#include <thread>
+#include <grpc++/grpc++.h>
+#include <grpc/support/log.h>
+#include "pybullet.grpc.pb.h"
+
+using grpc::Server;
+using grpc::ServerAsyncResponseWriter;
+using grpc::ServerBuilder;
+using grpc::ServerContext;
+using grpc::ServerCompletionQueue;
+using grpc::Status;
+using pybullet_grpc::PyBulletCommand;
+using pybullet_grpc::PyBulletStatus;
+using pybullet_grpc::PyBulletAPI;
+
+
+SharedMemoryCommand* convertGRPCAndSubmitCommand(PyBulletCommand& grpcCommand, SharedMemoryCommand& cmd)
+{
+	SharedMemoryCommand* cmdPtr = 0;
+
+	if (grpcCommand.has_loadurdfcommand())
+	{
+		auto grpcCmd = grpcCommand.loadurdfcommand();
+
+		std::string fileName = grpcCmd.urdffilename();
+		if (fileName.length())
+		{
+			cmdPtr = &cmd;
+			b3SharedMemoryCommandHandle commandHandle = (b3SharedMemoryCommandHandle)cmdPtr;
+			b3LoadUrdfCommandInit2(commandHandle, fileName.c_str());
+
+			if (grpcCmd.has_initialposition())
+			{
+				const ::pybullet_grpc::vec3& pos = grpcCmd.initialposition();
+				b3LoadUrdfCommandSetStartPosition(commandHandle, pos.x(), pos.y(), pos.z());
+			}
+			if (grpcCmd.has_initialorientation())
+			{
+				const ::pybullet_grpc::quat4& orn = grpcCmd.initialorientation();
+				b3LoadUrdfCommandSetStartOrientation(commandHandle, orn.x(), orn.y(), orn.z(), orn.w());
+			}
+			if (grpcCmd.hasUseMultiBody_case()== ::pybullet_grpc::LoadUrdfCommand::HasUseMultiBodyCase::kUseMultiBody)
+			{
+				b3LoadUrdfCommandSetUseMultiBody( commandHandle, grpcCmd.usemultibody());
+			}
+			if (grpcCmd.hasGlobalScaling_case() == ::pybullet_grpc::LoadUrdfCommand::HasGlobalScalingCase::kGlobalScaling)
+			{
+				b3LoadUrdfCommandSetGlobalScaling(commandHandle, grpcCmd.globalscaling());
+			}
+			if (grpcCmd.hasUseFixedBase_case() == ::pybullet_grpc::LoadUrdfCommand::HasUseFixedBaseCase::kUseFixedBase)
+			{
+				b3LoadUrdfCommandSetUseFixedBase(commandHandle, grpcCmd.usefixedbase());
+			}
+			if (grpcCmd.urdfflags())
+			{
+				b3LoadUrdfCommandSetFlags(commandHandle, grpcCmd.urdfflags());
+			}
+
+		}
+	}
+
+	if (grpcCommand.has_stepsimulationcommand())
+	{
+		cmdPtr = &cmd;
+		b3SharedMemoryCommandHandle commandHandle = (b3SharedMemoryCommandHandle)cmdPtr;
+		b3InitStepSimulationCommand2(commandHandle);
+	}
+
+	return cmdPtr;
+}
+
+bool convertStatusToGRPC(const SharedMemoryStatus& serverStatus, char* bufferServerToClient, int bufferSizeInBytes, PyBulletStatus& grpcReply)
+{
+	bool converted = false;
+	grpcReply.set_statustype(serverStatus.m_type);
+
+	switch (serverStatus.m_type)
+	{ 
+	case CMD_URDF_LOADING_COMPLETED:
+	{
+		::pybullet_grpc::LoadUrdfStatus* stat = grpcReply.mutable_urdfstatus();
+		b3SharedMemoryStatusHandle statusHandle = (b3SharedMemoryStatusHandle)&serverStatus;
+		int objectUniqueId = b3GetStatusBodyIndex(statusHandle);
+		stat->set_objectuniqueid(objectUniqueId);
+	}
+
+	break;
+	
+	}
+	
+	return converted;
+}