OPENRNDR uses kotlin-logging, which is a Kotlin flavoured wrapper around slf4j, to log its internal workings. Log messages are displayed in the IDE’s console and saved to the application.log file.

Configure logging

In build.gradle.kts we can modify the applicationLogging variable.

  • Logging.NONE to disable logging.
  • Logging.SIMPLE to display monochrome log messages in the console.
  • Logging.FULL to display coloured log messages in the console to distinguish their types.

In src/main/resources/log4j2.yaml we can change the logging level. To make it verbose we can replace level: info with level: all.

Exception handling

It is possible to change how exception errors are presented by adding -Dorg.openrndr.exceptions=JVM to the VM options under Run > Edit Configurations. This can sometimes help figure out why a program is crashing.

Crashing shaders

If a ShadeStyle crashes, a ShaderError.glsl file is created at the root of the project. The content of the file is the actual shader program OPENRNDR tried to use. Studying this program can help figure out why shaders fail. A common reason is using incorrect names for methods, uniforms or variables.

Debugging video exporting

When a video file is produced, a ffmpegOutput.txt is created at the root of the project. Studying this file can help diagnose problems with video exporting.

Enabling OpenGL debug messages

If your graphics hardware and drivers support OpenGL debug contexts you can use -Dorg.openrndr.gl3.debug=TRUE to enable the debug messages.

Open the Run > Edit Configurations... menu in IntelliJ and make sure the VM Options text field contains -Dorg.openrndr.gl3.debug=true.

Using RenderDoc

RenderDoc is a graphics debugger currently available for Vulkan, D3D11, D3D12, OpenGL, and OpenGL ES development on Windows, Linux, Android, Stadia, and Nintendo Switch™.

This post explains how to use RenderDoc with OPENRNDR.

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