Command line arguments

All JVM system properties supported by OpenRocket, with usage examples.

OpenRocket accepts a number of JVM system properties that control debug behavior, UI theme, database loading, and more. Pass them with the -D flag when launching the JAR.

Usage

# General form — argument with a value
java -D{argument}={value} -jar OpenRocket.jar

# General form — flag argument (no value required)
java -D{argument} -jar OpenRocket.jar

Examples

# Set the UI theme to light
java -Dopenrocket.laf=LIGHT -jar OpenRocket.jar

# Start with extra debugging tools enabled
java -Dopenrocket.debug -jar OpenRocket.jar

# Start with a custom home directory
java -Duser.home=/path/to/custom/home -jar OpenRocket.jar

# Bypass motor and preset loading for faster startup
java -Dopenrocket.bypass.motors -Dopenrocket.bypass.presets -jar OpenRocket.jar

To find all uses of a given property in the codebase, search for System.getProperty("argument.name") in your IDE or with grep.

All supported arguments

Argument	Description
-Dopenrocket.debug	Start OpenRocket with extra debugging tools.
-Dopenrocket.debug.prefs	Use debugging preferences instead of the normal user preferences.
-Dopenrocket.debug.bugurl={url}	Override the URL used for bug reporting.
-Dopenrocket.debug.updateurl={url}	Override the URL used by the software updater.
-Duser.home={dir}	Set the home directory used by OpenRocket for preferences and files.
-Dos.name	Override the reported operating system name.
-Dopenrocket.airstart.altitude	Set the altitude for air-start simulations.
-Dopenrocket.debug.safetycheck	Enable additional runtime safety checks.
-Dopenrocket.debug.coordinatecount={count}	Print a log line after every n Coordinate object instantiations.
-Dopenrocket.debug.quaternioncount={count}	Print a log line after every n Quaternion object instantiations.
-Dopenrocket.3d.disable	Disable the 3D view. Use this if OpenRocket fails to start due to a 3D rendering problem.
-Dopenrocket.debug.motordigest	Enable motor digest debugging output.
-Dopenrocket.preseteditor.fileMenu	Activate the experimental component preset editor window.
-Dopenrocket.debug.fileMenu	Show the debug file menu with additional developer tools.
-Duser.country	Override the user’s country for locale selection.
-Djava.version	Override the reported Java version.
-Dopenrocket.ignore-jre	Skip the JRE version compatibility check at startup.
-Dopenrocket.laf={theme}	Set the UI look-and-feel theme. Accepted values: LIGHT, DARK.
-Dopenrocket.bypass.presets	Skip loading the component preset database (faster startup).
-Dopenrocket.bypass.motors	Skip loading the motor database (faster startup).
-Dopenrocket.debug.checkAllVersionUpdates	Check for all software updates, ignoring any previously dismissed “ignore this update” selections.

Development tips

Faster startup

Combine -Dopenrocket.bypass.presets and -Dopenrocket.bypass.motors to skip database loading during development when you do not need motor or preset data.

Theme testing

Use -Dopenrocket.laf=DARK or -Dopenrocket.laf=LIGHT to quickly switch themes without changing your saved preferences.

3D rendering problems

If OpenRocket fails to launch due to a JOGL (Java OpenGL) error, add -Dopenrocket.3d.disable to bypass the 3D view entirely.

Finding arguments in code

Search the codebase for System.getProperty("openrocket. to locate every place an argument is read and understand its exact effect.