It is an irrefutable fact that CryEngine is a fantastic game engine. This is made evident be the AAA titles that are being released. As a developer I have been keen to get in on this action and create my own stunning landscapes with a captivating storyline. However upon being faced with a blank canvas I really do feel like the David to this game engine Goliath.
This article clearly is not going to be an in depth discussion about how professionals use this engine and how to implement the next Crysis, however in this article you will learn the answers I had to some very basic question when starting out.
What is CryEngine V?
CryEngine V is the fifth major iteration of the CryEngine game engine developed by the German company Crytek. Since the release of the original engine in 2002 it has been used for all their titles and has been continually updated to support newer technologies, hardware and platforms. This brings us all the way to CryEngine V, released on 22 March 2016, to support a new licensing model allowing the engine to be used for free.
The implementation of a launcher, which is used to download the engine, is a much needed improvement. In the past when stating a game project a new copy of the engine would need to be downloaded and the game built around the engine source code. From talking to other game developers who used CryEngine back in these archaic days they said that they preferred that way of working. Although Crytek are not the first to do this I personally disagree with the other developers and am glad Crytek have taken this approach.
How does it differ from UE4 or other engines?
Before settling with CryEngine V I also ventured into UnrealEngine 4 (UE4) and Unity. Although all of these game engines offer similar features there were some key points that made CryEngine V stand out to me:
- 100% Royalty free. Unlike UE4 and Unity which require you to pay royalties when you hit the big time, CryEngine is completely royalty free,
- Real time sandbox editing. Both UE4 and Unity have this functionality, but it felt more solid in CryEngine,
- Single key press to jump straight into the game. This is facilitated without loading the game engine as it is already running within the editor,
- A lot of boilerplate is already done for you. A new project will start with an ocean, a small platform, a skybox and Time of Day (TOD) feature with daylight/nighttime transition. This was not something I found in UE4,
- An impressive sample level which I feel is more accessible than those on UE4 or Unity. For instance it runs on my mid spec Windows Desktop whereas the UE4 Infiltrator demo has no hope in hell of running on my machine.
What CryEngine is not
So far I have been singing CryEngine praises, but like most things it is not perfect. In particular:
- It is not as user friendly as other engines, although it is vastly more so than in previous versions,
- It currently has little support and scattered documentation,
- I found there to be a partially elitist community (at least those I spoke to on Slack), whilst the forums are most helpful,
- It’s asset store is lacking in… well, assets. I assume this will improve over time. CryEngine (with launcher and store) is very new so the community has yet to release many assets.
The Missing Answers
Now with an introduction to the game engine I present the questions that I had when starting to use CryEngine V.
1. How to Launch the Code, Editor and the Game?
I believe it is important to note that Visual Studio (or MonoDevelop for C#)
should be launched using the Code_CPP.bat file (Code_CS.bat for C#) created
after bootstrapping a new game project. This script creates a series of
environment variables that presumably enable Visual Studio to successfully
build the game.
Similarly launching the sandbox editor should be done via the Editor.bat file
or from the CryEngine Launcher.
Update: Now CryEngine 5.2 has been released the above has been updated.
Instead a working installation of CMake (3.6+) is required to generate a Visual
Studio (or MonoDevelop for C#) project file that can be opened through
explorer, whilst the editor and game are launched through the .cryproject
file.
2. How are the Config Files Loaded?
There are a couple of configuration files scattered around the engine and individual projects. These are loaded in a particular order as discussed below:
system.cfg is the first config file loaded by the engine and found in the
engine root. I tend not to touch this file and pretend it does not exist.
Unless I know I want a certain configuration for every game I plan to create it
will suffice to put my game configs elsewhere. The exception to this is the
audio middleware. It was recommended that I switch middleware in here.
editor.cfg is loaded next and also found in the engine root. Presumably this
config applies only to the editor. As with system.cfg, unless I know I want a
certain configuration for every game I wont edit this file.
game.cfg is loaded next. This is the configuration file for the specific
project.
Update: Prior to version 5.2 project.cfg is the loaded last. This file
seemed superflous to me as game.cfg would do the job. It would appear it has
been removed.
Upadte: Having updated to version 5.3 it appears that system.cfg has been
removed so I was unable to continue using this file to host my audio middleware
configurations. Instead I have moved it over to game.cfg. This has made a
little more sense to me considering how the new plugin system is supposed to
help separate engine logic from specific game code. Putting my configurations
variables here keeps all my game specific values in one place.
The various configuration variables and console commands are documented on the
CryEngine website and prefixed with the initials of it parent subcomponent of
the engine. For example the s_ prefix is for the sound engine subcomponent. A
full list of the available configuration variables can be found
here.
3. What is the Resource Compiler?
The MakeAssets.bat invokes the the resource compiler (rc.exe) that optimises
assets for the specific platform. Some useful resources referencing the
resource compiler can be found on the CryEngine website. Ones of note are:
using the resource
compiler
and compiling assets for multiple
platforms.
Furthermore MakeAssets.bat contains syntax such as %~dp0. This is a Windows
shell command that expands the full path to the file (including the drive
letter drive). More on this can be found in
this StackOverflow answer.
Update: In version 5.2 of the engine this feature seems to be broken since the project.cfg file was removed. I questioned this on the forums to only have it confirmed. Hopefully this will be fixed ASAP.
Update: In version 5.3 MakeAssets.bat has been removed from the game
templates. I can only assume it is now handled entirely within the CMake
system.
4. How to implement Wwise sound engine?
When I start a project I like to setup and integrate all the other 3rd party software I intend to use first. So to begin I wanted to switch the audio middleware that the engine uses. By default this is SDL Mixer. In order for the engine to interact with different audio middleware it implements an Audio Translation Layer (ATL) which is an abstraction interface between CryEngine and other audio middlewares i.e. Wwise.
I wont be going through the setup of Wwise in this article as it is covered well here but the two important console commands I used are:
s_DrawAudioDebug 1 <-- Display debug information about ATL middleware.
s_AudioImplName CryAudioImplWwise <-- Switch to the Wwise audio middleware. Other options include CryAudioImplFmod (for fmod studio) and CryAudioImplSDLMixer (for sdl mixer).I also set these in my system.cfg file as mentioned earlier. Now every time I
create a new project, or launch a current project the correct audio middleware
is selected.
Update: As of version 5.3 I have transitioned this configuration to
game.cfg as system.cfg has been removed (at least according to my editor
log file which is unable to find it).
5. How is the C++ Sample Project Structured?
I lean toward using C++ when I can. It seems to have been the industry standard for many years so there must be something about it that lends itself well to games. Alternatively it was just the only decent language available at the time and has just stuck. Regardless, the C++ project the launcher generates includes a little boilerplate that is not well documented and I simply am unsure what it all does, whether it is necessary and whether I can remove it without breaking everything.
I’m cautious that this is an example of functional fixedness, a bias limiting me to using the engine only in the way it has traditionally been used. So I intend to figure out what were the intentions of having included these particular boilerplate features, yet not implement others? Beyond this I intend to find what each bit does.
6. What is Included in the Assets Folder?
The Assets folder contains Textures.pak. What is the difference between this
and the terraintexture.pak within Assets/levels/example? I assume
Textures.pak are global textures whereas terraintexture.pak contains
textures pertaining to a particular levels landscape including height maps,
normal maps etc…
Moving Forward
I am clearly still no expert here, with some questions still unanswered. I fully intend to keep this article up to date whilst I discover more answers to my questions, perhaps adding further questions as they develop.
Please leave comments correcting any of my assumptions as I have likely made many mistakes in my findings. I would like this to turn into a great starting out guide to those jumping in at the deep end like myself.