validation-diff-gifs

Testing & Quality

Generate pixel-difference GIF animations comparing benchmark validation captures against golden images. Use when the user asks to visualize validation failures, compare captured vs golden images, generate diff GIFs, or debug image tolerance issues.

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Validation Difference GIFs

Generate per-camera GIF animations showing the pixel-wise difference between captured benchmark images and their golden references. Useful for debugging validation tolerance failures.

Prerequisites

ImageMagick (composite, convert) must be available on PATH.
A completed validation capture run with matching directory structure to the golden data.

Paths

Captures and golden data live under the Isaac Sim build release directory:

standalone_examples/benchmarks/validation/captures/<run_name>/
standalone_examples/benchmarks/validation/golden_data/<benchmark_name>/

Both share a parallel directory tree (e.g. Robots/Robot_0/.../front_hawk/left/camera_left/rgb/).

Usage

Find the latest capture

ls -td standalone_examples/benchmarks/validation/captures/benchmark_robots_nova_carter_ros2_*/ | head -1

Run the script

The bundled script is resolved via ${CLAUDE_SKILL_DIR}; falls back to the canonical repo path skills/validation-diff-gifs/scripts/:

bash "${CLAUDE_SKILL_DIR:-skills/validation-diff-gifs}/scripts/generate_diff_gifs.sh" \
    <captured_run_dir> \
    <golden_benchmark_dir> \
    [amplify] [fps]

Argument	Default	Description
`captured_run_dir`	(required)	Root of the capture run
`golden_benchmark_dir`	(required)	Root of the golden data for the benchmark
`amplify`	`10`	Multiply pixel differences by this factor for visibility
`fps`	`5`	Frame rate for the output GIF

Example

LATEST=$(ls -td standalone_examples/benchmarks/validation/captures/benchmark_robots_nova_carter_ros2_*/ | head -1)
GOLDEN="standalone_examples/benchmarks/validation/golden_data/benchmark_robots_nova_carter_ros2"

bash "${CLAUDE_SKILL_DIR:-skills/validation-diff-gifs}/scripts/generate_diff_gifs.sh" "$LATEST" "$GOLDEN"

Output

For each rgb/ directory under the capture, a diff_animation.gif is written alongside the captured PNGs:

<captured_run_dir>/Robots/.../front_hawk/left/camera_left/rgb/diff_animation.gif

Black pixels = identical between captured and golden
Brighter pixels = larger difference (amplified by the amplify factor)

Interpreting results

Uniform low-level noise across the frame → rendering non-determinism (likely acceptable)
Bright regions concentrated on object edges → sub-pixel movement differences
Entire frame bright → wrong timestamp match or completely different camera pose
One camera consistently worse than others → possible per-camera issue (tick rate, initialization)