renderdoc-gpu-debug

RenderDoc GPU Debugging Skill

Overview

This skill enables GPU frame capture, inspection, and debugging using rdc-cli, a 66-command CLI wrapping RenderDoc's Python API. It works with Vulkan, D3D11, D3D12, and OpenGL applications.

Prerequisites

Before any GPU debugging, verify the environment:

rdc doctor

All checks should pass. If rdc doctor fails, check:

• RENDERDOC_PYTHON_PATH is set to the directory containing renderdoc.pyd
• renderdoc.dll is in the same directory as renderdoc.pyd
• renderdoccmd.exe is on PATH or in the module directory

1. Session Lifecycle

Every inspection session follows open-work-close:

rdc open path/to/capture.rdc   # Start daemon, load capture
# ... inspection commands ...
rdc close                       # Release resources, stop daemon

Check session state with rdc status. Only one capture can be open per session (use --session name for parallel sessions).

IMPORTANT: Always close sessions when done. Leaked daemon processes consume GPU memory.

2. Capture Workflow

Capture from an executable

rdc capture -o output.rdc -- /path/to/app [app-args...]

Key options:

• -o, --output: Output .rdc file path
• --frame N: Capture frame N (default: first presented frame)
• --timeout S: Capture timeout in seconds (default: 60)
• --api-validation: Enable API validation layer
• --ref-all-resources: Reference all resources (larger capture, more complete)
• --wait-for-exit: Wait for the app to exit after capture

CWD matters

Many applications resolve assets relative to CWD. Always set CWD appropriately:

cd /path/to/app/root && rdc capture -o /output/path/capture.rdc -- ./app

For lux-playground specifically:

cd D:/shaderlang && python D:/renderdoc/capture_frame.py

Vulkan layer requirement

For Vulkan apps, the RenderDoc Vulkan layer must be registered:

• Registry: HKCU\SOFTWARE\Khronos\Vulkan\ImplicitLayers must contain D:\renderdoc\module\renderdoc.json (DWORD 0)
• Environment: ENABLE_VULKAN_RENDERDOC_CAPTURE=1 must be set