Add light color temperature variation

[alexmillane]

Summary

Adds a light color variation.

Detailed description

• Light color plugs into an existing Lab parameter for all lights.

[arena-review-bot]

🔵 This class is structurally identical to LightIntensityVariation (sample one scalar → call a setter), differing only in the cfg's default range and which setter it invokes. With intensity and now temperature following the same shape, is it worth collapsing the single-scalar cases into one generic variation parameterized by the setter + default range (thin Cfg subclasses, or just cfg instances)? Not a blocker — more a question of whether this family is now large enough to earn a shared base rather than a third near-copy.

[arena-review-bot]

🤖 Isaac Lab-Arena Review Bot

Summary

Adds a build-time LightColorTemperatureVariation that samples a white-point color temperature (Kelvin) and applies it to dome and directional lights via a new LightBase.set_color_temperature. The change is small, self-consistent, and mirrors the existing LightColorVariation / LightIntensityVariation pattern faithfully. Variations default to enabled=False, so the new behavior is opt-in and does not change the default path — good.

Findings

🔵 Improvement: variations/light_color_temperature_variation.py — This class is structurally identical to LightIntensityVariation (sample one scalar → call a setter), differing only in the default range and the setter it calls. With two near-copies now, worth considering a shared generic single-scalar variation. Non-blocking.

Test Coverage

Strong. test_light_color_temperature_variation.py covers both the disabled (unchanged cfg) and enabled (mutated + compiled-into-scene) paths for both light and directional_light, using the inner/outer run_simulation_app_function pattern and a degenerate sampler range for determinism — consistent with the sibling test_light_color_variation.py.

Verdict

Ship it

[greptile-apps]

Greptile Summary

This PR adds a new LightColorTemperatureVariation build-time variation that randomizes the white-point color temperature (in Kelvin) on DomeLight and DirectionalLight assets. It follows the established pattern of LightColorVariation and LightIntensityVariation, plugging into the same BuildTimeVariationBase infrastructure.

• Adds set_color_temperature() to LightBase, which also forces enable_color_temperature = True on the spawner config, and wires the new LightColorTemperatureVariation into both DomeLight and DirectionalLight constructors.
• The default sampler range is [2000, 10000] K, but the valid range accepted by set_color_temperature is [1000, 10000] K, leaving the warmest candlelight tones (1000–2000 K) unreachable via the default configuration.

Confidence Score: 4/5

Safe to merge; the new variation correctly wires into both DomeLight and DirectionalLight using the established build-time pattern, and the tests cover the disabled and enabled paths end-to-end.

The implementation is consistent with sibling variations and correctly delegates to the validated set_color_temperature API. The only gap is that the default sampler range starts at 2000 K while the API it calls accepts values down to 1000 K, leaving the warmest tones unreachable via the default configuration without an explicit override.

isaaclab_arena/variations/light_color_temperature_variation.py — the default sampler lower bound.

Important Files Changed

Filename	Overview
isaaclab_arena/variations/light_color_temperature_variation.py	New variation class, cleanly mirrors LightColorVariation; default sampler lower bound (2000 K) is narrower than the valid range (1000 K) accepted by set_color_temperature.
isaaclab_arena/assets/object_library.py	Adds set_color_temperature() to LightBase and wires LightColorTemperatureVariation into DomeLight and DirectionalLight; logic is correct and consistent with existing set_intensity/set_color patterns.
isaaclab_arena/tests/test_light_color_temperature_variation.py	New test file covering both the disabled (no-mutation) and enabled (mutation + compiled cfg) paths for both DomeLight and DirectionalLight; degenerate-range sampler trick is a solid determinism pattern.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[LightColorTemperatureVariation.apply] --> B{sampler set?}
    B -- No --> C[AssertionError]
    B -- Yes --> D[sampler.sample num_samples=1]
    D --> E[color_temperature = float result 0,0]
    E --> F[LightBase.set_color_temperature]
    F --> G{1000 <= temp <= 10000?}
    G -- No --> H[AssertionError]
    G -- Yes --> I[spawner_cfg.enable_color_temperature = True]
    I --> J[spawner_cfg.color_temperature = value]
    J --> K[object_cfg = _init_object_cfg]

    subgraph Registration
        L[DomeLight.__init__] --> M[add_variation LightColorTemperatureVariation]
        N[DirectionalLight.__init__] --> M
    end

Loading

%%{init: {'theme': 'base', 'themeVariables': {"darkMode": true, "background": "#0d1117", "primaryColor": "#21262d", "primaryTextColor": "#e6edf3", "primaryBorderColor": "#8b949e", "lineColor": "#8b949e", "textColor": "#e6edf3", "edgeLabelBackground": "#161b22", "actorBkg": "#21262d", "actorBorder": "#8b949e", "actorTextColor": "#e6edf3", "actorLineColor": "#8b949e", "signalColor": "#8b949e", "signalTextColor": "#e6edf3", "noteBkgColor": "#373320", "noteBorderColor": "#d4a72c", "noteTextColor": "#f0e6c0", "labelBoxBkgColor": "#21262d", "labelBoxBorderColor": "#8b949e", "labelTextColor": "#e6edf3", "loopTextColor": "#e6edf3", "activationBkgColor": "#30363d", "activationBorderColor": "#8b949e"}}}%%
flowchart TD
    A[LightColorTemperatureVariation.apply] --> B{sampler set?}
    B -- No --> C[AssertionError]
    B -- Yes --> D[sampler.sample num_samples=1]
    D --> E[color_temperature = float result 0,0]
    E --> F[LightBase.set_color_temperature]
    F --> G{1000 <= temp <= 10000?}
    G -- No --> H[AssertionError]
    G -- Yes --> I[spawner_cfg.enable_color_temperature = True]
    I --> J[spawner_cfg.color_temperature = value]
    J --> K[object_cfg = _init_object_cfg]

    subgraph Registration
        L[DomeLight.__init__] --> M[add_variation LightColorTemperatureVariation]
        N[DirectionalLight.__init__] --> M
    end

Loading

_{Reviews (1): Last reviewed commit: "Add light color temperature variation" | Re-trigger Greptile}

[greptile-apps]

The default sampler lower bound is 2000 K while set_color_temperature documents and validates the full range [1000, 10000] K. With this default, the warmest tones (1000–2000 K — candlelight, incandescent bulbs) can never be sampled unless the caller explicitly overrides sampler_cfg. Aligning the default to 1000 K makes the variation self-consistent with the API it calls.

Suggested change

	sampler_cfg: UniformSamplerCfg = field(default_factory=lambda: UniformSamplerCfg(low=[2000.0], high=[10000.0]))
	sampler_cfg: UniformSamplerCfg = field(default_factory=lambda: UniformSamplerCfg(low=[1000.0], high=[10000.0]))

[cvolkcvolk]

Is there a reason to constrain it to 1000, 10000?

[cvolkcvolk]

lgtm