UE Viewer is a viewer for visual resources of games made with Unreal engine. Currently all engine versions (from 1 to 4) are supported.

The project was originally named the "Unreal model viewer", however the name was changed in 2011 to meet the request from Epic Games. Please note that "official" project's name is "UE Viewer", and a short unofficial name of the project is "umodel" (it was left from the older name "Unreal MODEL viewer").

There's a place where you may discuss the source code: gildor.org forums.

The source code is available at GitHub. You may either checkout it with use of any Git client, or download it as a Zip file.

We are using own build system to compile UE Viewer. You may find a Perl script in Tools/genmake. This script generates makefiles from some human-friendly project format. After that you may build generated makefile using 'nmake' for Visual Studio or 'make' for gcc. Build process is controlled with build.sh script.

To list all options, run build.sh --help. Current options are:

• --64 compile for Windows 64bit
• --debug make a debug version of executable
• --profile make a special build which is intended to use with external profiler
• --vc <version> specify which Visual Studio version should be used for compilation, default is latest compiler installed on your system

Please note that build.sh is not just a shortcut for calling make -f <makefile>, it performs more actions. It does:

• Generating a makefile for current platform.
• Making UModelTool/Version.h file which contains current build number based on number of Git commits.
• Preprocessing shaders (with executing Unreal/Shaders/make.pl).
• It has the possibility to compile just a single cpp file from the project (used with Visual Studio Code Ctrl+F7 key).

UE Viewer is compiled using Visual Studio. Required VisualStudio 2013 or newer. Older Visual Studio compilers are not suitable because viewer's code using some C++11 stuff.

Currently build is performed with Visual C++ 2019.

Build system utilizes GNU Tools for building, in particular - Bash and Perl. I've packaged Windows versions of these tools which was a part of MinGW/MSYS project. You can get everything what you need for a build here. You should download it and extract into some directory (press the green button "Clone or download", then "Download ZIP"). Let's say you extracted everything to C:\BuildTools. After that, add C:\BuildTools\bin to the system's PATH environment variable. As an alternative it is possible to create a batch file which will temporarily modify PATH and then execute build script. Here's an example of such file:

@echo off
set PATH=C:\BuildTools\bin;%PATH%
bash build.sh

To launch a build process without a batch, simply execute

bash build.sh

Despite only 32-bit builds of UE Viewer being provided, it is possible to compile it for 64-bit platform. To do that, you should change a variable in build.sh: PLATFORM should be changed from vc-win32 to vc-win64. Also 64-bit build could be initiated with launching

build.sh --64

Linux system has the most of dependencies by default. You'll need to install the following development packages if they're not available on your system: SDL2, zlib, libpng. Of course, you'll also need gcc for compiling the project. To build UE Viewer, simply execute the following command from terminal

./build.sh

When compiling for Linux, project will use system's zlib and libpng libraries. If you want to bundle (statically link) them into umodel executable, you may find and comment the following line in common.project

USE_SYSTEM_LIBS = 1

In this case, Linux build will be performed in the same way as Windows build, with compiling and bundling mentioned libraries.

UE Viewer is provided with initial support for macOS platform. I'm using VMWare macOS image to build it, so I can't do the full testing. Therefore, some features are disabled:

• no OpenGL support (no visualization) - it is explicitly disabled in UmodelTool/Build.h
• no multithreading support - it's disabled in the same place

In other words, UE Viewer on macOS works just like a simple command-line exporter utility.

As UE Viewer is using custom cross-platform build system, there's no MSBuild support. However we have a simple Visual Studio project which allows to use this IDE to edit, compile, run and debug the project. Project files are located in .vs directory. In order to open the project, you should start Visual Studio, use "Open a local folder" command, and then choose root project's directory. Please note: there's .sln file somewhere in Tools folder, don't use it - it is intended for UI framework testing.

Please note that you should use Visual Studio 2019 or newer, otherwise some features will not work.

UE Viewer contains project files needed for opening and running it from Visual Studio Code. Just open viewer's folder in VSCode, and you'll get everything. Project already has a build task and launch actions set up. Of course you'll need a C/C++ extension installed. You may build, launch and debug UE Viewer using this IDE.

VSCode project comes with additional build command which could be bound to a key. Just use

	{
		"key": "ctrl+f7",
		"command": "workbench.action.tasks.runTask",
		"args": "Compile"
	}

and then Ctrl+F7 key will compile a file currently opened in editor. Of course, it won't work for headers and other non-cpp files.

By default, Visual Studio Code project performs Debug build. If you want something else, change .vscode/tasks.json file, and remove --debug option from build.sh command.

There are 2 configurations For debugging: "No arguments" runs UE Viewer with default startup UI, and for use of command line you may launch 2nd "Volatile" configuration, which reads command line arguments from file docs/cmdline.cfg - please refer to Response files documentation for details on its format. You may also edit .vscode/tasks.json file to add your own debug configurations.

Initially UE Viewer was released without a Visual Studio solution. However it was possible to debug it within an IDE. The information below describes how to build and debug UE Viewer for debugging without use of VS project (e.g. when you're using older IDE version).

You can build a Debug version of viewer by uncommenting #define MAX_DEBUG 1 in UmodelTool/Build.h and rebuilding the project. After that you'll get executable with optimizations disabled, and with some extra features. For example, if umodel.exe crashes, and it is started with -debug option, standard Windows window appears with prompt to close program or debug it. You may choose "Debug with Visual Studio" there.

Also you may use --debug parameter for build.sh script. This will generate separate set of object files and link into debug version of the executable (with the same executable file's name). You may quickly switch between "debug" and "release" builds without having to fully recompile the program.

If you want to debug umodel.exe in Visual Studio without having a crash, you may load it either from IDE (File | Open | Project/Solution, then select umodel.exe), or you may type in console

devenv umodel.exe

It is recommended to use Visual Studio 2013 IDE or newer because it has more advanced debugging features than previous studio versions. You may copy Tools/umodel.natvis file to C:\Users\Your_user_folder\My Documents\Visual Studio 20NN\Visualizers, and after that you'll be able to view TArray and FString structures during debug session.

UE Viewer is dynamically linked with CRT library, so it requires CRT DLL files to be installed onto your system. It is possible to statically link with you compiler's CRT by changing a line in common.project (with cost of growing executable file size):

LIBC = shared

to

LIBC = static

UE Viewer uses custom CRT library for being able to link against MSVCRT.DLL. MSVCRT.DLL is chosen because it allows to reduce size of UE Viewer distribution without needs to install compiler runtime libraries onto a Windows system - MSVCRT.DLL present on any Windows installation. You may disable MSVCRT.DLL linking by commenting out the line

OLDCRT = 1

Previously there were some problems with using msvcrt.dll with Visual Studio compiler 2015 and newer. However all issues has been solved. For those who interested in details, I've prepared an article.

If you want to use MSVCRT.DLL, you should extract MSVCRT.zip archive available here to the directory LIBS one level above of UModel directory. So, the directory structure should look like this

├── Libs
│   └── MSVCRT
│       ├── include
│       ├── lib
│       └── msvcrt.project
├── UModel
│   ├── Core
│   ├── Unreal
│   ...
│   ├── build.sh
│   ...

Also you may change MSVCRT library path by changing WDKCRT variable in common.project.

Below is the list of major folders which exists in this repository or which are generated during build process.

├── .vs                   # Visual Studio 2019 project files
├── .vscode               # Visual Studio Code project files
├── Core                  # corelibraries not related to Unreal engine
│   └── GL                # OpenGL wrapper builder
├── Docs                  # miscellaneous text files
├── Exporters             # exporters for different object types
├── Libs                  # third-party libraries used for building
├── MeshInstance          # mesh renderers
├── obj                   # all compiled object files goes there
├── Tools
│   ├── CompatTable       # source of compatibility table
│   ├── MaxActorXImport   # ActorX Importer script for 3ds Max
│   ├── PackageExtract    # Unreal package extractor source
│   └── PackageUnpack     # unreal package decompressor source
├── UI                    # library used to show UI on Windows
├── UmodelTool            # source code of umodel itself
├── Unreal                # source code of Unreal Engine framework
│   └── Shaders           # shaders used in UModel's renderer
├── Viewers               # viewers for different object types
├── build.sh              # main build script
├── common.project        # main project file, reused between different sub-projects
├── t.bat                 # Windows CMD caller for test.sh
└── test.sh               # internal script used for testing

UE Viewer is licensed under the MIT License, see LICENSE.txt for more information.