Welcome to the Infraworld Runtime example project. The main goal of this tutorial is to show you how to get Infraworld sources, to generate grpc/protobuf and protocol/transport code using Infraworld Protobuild tool, to generate Unreal Engine friendly code with Infraworld Cornestone and finnaly how to connect all this stuff together to integrate InfraworldRuntime plugin into your UE project.
Infraworld is divided into three pieces:
-
Infraworld Protobuild is an optional build tool helping you to keep your protobuf and gRPC wrapper code in a consistent state for all programming languages you're using across your projects.
-
Infraworld Cornerstone is an optional converter utility, used to generate UE4-friendly code to provide gRPC functionality into your game.
-
Infraworld Runtime - is a required library that enables Unreal Engine 4 to work with Google gRPC services using either C++ or Blueprints.
In this tutorial I want to show how to create a simple grpc server written in python which can handle two simple requests: Hello(string name) that takes a string and returns an other sting to the client like Hello ${name}. Second message ServerTimeRequest takes no arguments and returns server time structure like:
struct
{
int64 unixTimeStamp;
uint32 hours;
uint32 minutes;
uint32 seconds;
string timezone;
string location;
}
Also you need to download InfraworldRuntime plugin. You can download precompiled binaries from the release page or clone and build the project by yourself. After this you have to copy the InfraworldRuntime plugin folder into ${InfraworldDemo}/Plugins
First of all, you need at least one .proto file. Let's create a directory called proto for this. In proto directory create a file called vizor_demonstration.proto
Let's describe which requests we can send to the server and what do we expect to receive on the client:
syntax = "proto3";
package vizor_proto_demostration;
service HelloService
{
rpc Hello (HelloRequest) returns (HelloResponse) {}
rpc ServerTime (ServerTimeRequest) returns (ServerTimeResponse) {}
}
message HelloRequest
{
string name = 1;
}
message HelloResponse
{
string message = 1;
}
message ServerTimeRequest {}
message ServerTimeResponse
{
int64 unixTimeStamp = 1;
uint32 hours = 2;
uint32 minutes = 3;
uint32 seconds = 4;
string timezone = 5;
string location = 6;
}Click here for proto 3 language specification.
Great! We're done with the dull part, let's roll!
Tip: you can skip this part because this example repository already contains generated transpot code, but it is not recommended .
To start doing this, you need to have an Infraworld Protobuild. You can read how to use it in it's README.md file. Don't forget to add python language to the protobuild.yml into the languages section because our server will be in python.
As the result, your output directory(gen_root parameter in protobuild.yml) should look like this:
gen_root (protobuild output directory)
|
|---cpp
| |---vizor_demonstration
| |---vizor_demonstration.grpc.pb.h
| |---vizor_demonstration.grpc.pb.hpp
| |---vizor_demonstration.pb.h
| |---vizor_demonstration.pb.hpp
|
|---python
| |---vizor_demonstration
| |---vizor_demonstration_pb2.py
| |---vizor_demonstration_pb2_grpc.py
|
|--- ...
Copy all files from the gen_root/cpp/vizor_demonstration to path/to/InfraworldRuntimeExample/Source/InfraworldDemo/Wrappers/proto/vizor_demonstration. Also, you need to copy all generated python files into path/to/InfraworldRuntimeExample/DemoServer folder.
Tip: you can skip this part because this example repository already contains generated code for the InfraworldRuntime, but it is not recommended.
Clone this repository. Remeber that the Cornerstone is written in java so you need jdk8+ and maven installed on your system. Then you need to run mvn install under Cornerstone directory. You can then find infraworld-cornerstone.jar in the target directory.
Create config.yml file in same directory with infraworld-cornerstone.jar and add the following fields:
src_path: 'path/to/proto/files'
dst_path: 'path/to/generated/output/files'
module_name: 'InfraworldDemo'
precompiled_header: ''
wrappers_path: 'Wrappers'
company_name: 'Vizor'
Tip: For more information about Cornerstone building and configuring read README.md file.
When Cornerstone is being successfully built and configured - you can simply run it by command: java -jar infraworld-cornerstone.jar
After generation complete your dst_path directory should look like this:
generated
└── vizor_demonstration
├── VizorDemonstration.cpp
└── VizorDemonstration.h
Copy VizorDemonstration.h and VizorDemonstration.cpp files to path/to/InfraworldRuntimeExample/Source/InfraworldDemo
At this point our example Unreal Engine 4 project have all necessary source files and we are ready to compile and run it!
If you're working on windows - you need to generate Visual Studion solution for InfraworldExample project. Right click on InfraworldDemo.uproject and select Generate Project Files section.
After that, the InfraworldDemo.sln file should appear. Open it with the Visual Studio and select Development Editor configuration then right click on InfraworldDemo project and select build.
In the DemoServer directory you can find all server source files. Run pip3 install -r Requirements.txt. Tip: Maybe you should run pip instead pip3 (depends on your environment).
After all dependences are installed, you will be ready to run the demo server by executing command: python3 vizor_demo_server.py. Tip: Maybe you should run python instead python3 (depends on your environment). If the server started successfully you will see output like:
Server Started!
Tip: The Demo Server by default is using the 50051 port.
When you have compiled the UE4 project, and your server is running, you can open InfraworldDemo.uproject: just double click on it.
In the Unreal Editor, the default ThirdPersonExampleMap.umap should be loaded. You can look at ThirdPersonCharacter on the scene and its blueprint ThirdPersonCharacter.uasset, this blueprint contains all grpc client logic. As you can see, OnLeftMouseButtonReleased and OnRightButtonReleased are used to send HelloRequest and ServerTimeRequest.
So, you can press Play button in Editor and see how it works!
Tip: All responses and grpc errors are being printed on the screen.
Feel free to create an issue or contact us via email:
nikita.miroshnichenko@vizor-games.com
roman.chehowski@vizor-games.com