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Customizing O3DE Console

The console is a user interface system which handles console commands and console variables. It also outputs log messages and stores the input and output history.

Color coding

The game console supports color coding by using the color indices 0..9 with a leading $ character. The code is hidden in the text outputted on the console. Simple log messages through the ILog interface can be used to send text to the console.

This is normal $1one$2two$3three and so on

In the preceding example, one renders in red, two in green, and three (and the remaining text) in blue.

Console Variables

Console variables (cvars) provide a convenient way to expose variables which can be modified easily by the user either by being entered in the console during runtime or by passing it as command-line argument before launching the application.

Registering new console variables

For an integer or float based console variable, it is recommended to use the IConsole::Register() function to expose a C++ variable as a console variable.

To declare a new string console variable, use the IConsole::RegisterString() function.

Accessing console variables from C++

Console variables are exposed using the ICVar interface. To retrieve this interface, use the IConsole::GetCVar() function.

The most efficient way to read the console variable value is to access directly the C++ variable bound to the console variable proxy.

Adding New Console Commands

The console can easily be extended with new console commands. A new console command can be implemented in C++ as a static function which follows the ConsoleCommandFunc type. Arguments for this console command are passed using the IConsoleCmdArgs interface.

The following code shows the skeleton implementation of a console command:

static void RequestLoadMod(IConsoleCmdArgs* pCmdArgs);

void RequestLoadMod(IConsoleCmdArgs* pCmdArgs)
{
  if (pCmdArgs->GetArgCount() == 2)
  {
	 const char* pName = pCmdArgs->GetArg(1);
	 // ...
  }
  else
  {
    // error
  }
}

The following code will register the command with the console system:

IConsole* pConsole = gEnv->pSystem->GetIConsole();
pConsole->AddCommand("g_loadMod", RequestLoadMod);

Console Variable Groups

Console variable groups provide a convenient way to apply predefined settings to multiple console variables at once.

Console variables are commonly referred to as CVarGroup in the code base. Console variable groups can modify other console variables to build bigger hierarchies.

Caution:
Cycles in the assignments are not detected and can cause crashes.

Registering a new variable group

To register a new variable group, add a new .cfg text file to the GameSDK\config\CVarGroups directory.

sys_spec_Particles.cfg

[default]
; default of this CVarGroup
= 4
e_particles_lod=1
e_particles_max_emitter_draw_screen=64

[1]
e_particles_lod=0.75
e_particles_max_emitter_draw_screen=1

[2]
e_particles_max_emitter_draw_screen=4

[3]
e_particles_max_emitter_draw_screen=16

This creates a new console variable group named sys_spec_Particles that behaves like an integer console variable. By default, this variable has the state 4 (set in the line following the comment in the example).

On changing the variable, the new state is applied. Console variables not specified in the .cfg file are not set. All console variables need to be part of the default section. An error message is output in case of violation of this rule.

If a console variable is not specified in a custom section, the value specified in the default section is applied.

Console variable group documentation

The documentation of the console variable group is generated automatically.

sys_spec_Particles

Console variable group to apply settings to multiple variables

sys_spec_Particles [1/2/3/4/x]:
 ... e_particles_lod = 0.75/1/1/1/1
 ... e_particles_max_screen_fill = 16/32/64/128/128
 ... e_particles_object_collisions = 0/1/1/1/1
 ... e_particles_quality = 1/2/3/4/4
 ... e_water_ocean_soft_particles = 0/1/1/1/1
 ... r_UseSoftParticles = 0/1/1/1/1

Checking if a console variable group value represents the state of the variables it controls

From the console

In the console you can enter in the console variable group name and press tab. If the variable value is not represented, it will print the value of RealState.

sys_spec_Particles=2 [REQUIRE_NET_SYNC] RealState=3
sys_spec_Sound=1 [REQUIRE_NET_SYNC] RealState=CUSTOM
sys_spec_Texture=1 [REQUIRE_NET_SYNC]

By calling the console command sys_RestoreSpec you can check why the sys_spec_ variables don’t represent the right states.

From C++ code

From the code you can use the member function GetRealIVal() and compare its return value against the result of GetIVal() in ICVar.

Deferred execution of command line console commands

The commands that are passed via the command line by using the + prefix are stored in a separate list as opposed to the rest of the console commands.

This list allows the application to distribute the execution of those commands over several frames rather than executing everything at once.

Example

Consider the following example.

--- autotest.cfg --
hud_startPaused = "0"
wait_frames 100
screenshot autotestFrames
wait_seconds 5.0
screenshot autotestTime

-- console --
StarterGameLauncher.exe -devmode +map SinglePlayer +exec autotest +quit

In the example, the following operations were performed:

  • Load the SinglePlayer map.
  • Wait for 100 frames.
  • Take a screenshot called autotestFrames.
  • Wait for 5 seconds.
  • Take a screenshot called autotestTime.
  • Quit the application.

Details

Two categories of commands are defined: blocker and normal.

For each frame, the deferred command list is processed as a fifo. Elements of this list are consumed as long as normal commands are encountered.

When a blocker is consumed from the list and executed, the process is delayed until the next frame. For instance, commands like map and screenshot are blockers.

A console command (either command or variable) can be tagged as a blocker during its declaration using the VF_BLOCKFRAME flag.

The following synchronization commands are supported.

Optional Title

CommandTypeDescription
wait_frames num:Wait for num frames before the execution of the list is resumed.
wait_seconds sec:Wait for sec seconds before the execution of the list is resumed.