Adds Debug Draw Interface

[renezurbruegg]

Description

This PR streamlines the workflow for using the debug draw interface in IsaacLab.

Problem

At the moment, debug_draw is not convenient to use:

• Each component must access the raw draw_interface directly.
• Users need to manually clear previous drawings when visualizing different elements across simulation steps.
• This makes it difficult (and error-prone) when multiple components attempt to draw simultaneously, as each component either removes the previous drawing or the drawings accumulute over all the simulation steps.

Solution

Introduce a singleton DrawInterface, exposed through the SimulationContext.
This interface automatically manages clearing, caching, and rendering, enabling simple and consistent debug visualizations without interfering across components.

Example Usage

def _debug_vis_callback(self, event):
    draw_interface = SimulationContext.instance().draw_interface
    pts_x, pts_y, colors = ...  # compute line data
    draw_interface.plot_lines(pts_x, pts_y, colors)

You can run a demo (visualizing raycast sensor rays) with:

python scripts/demos/debug_draw.py

Additional Examples

The new interface also allows to:

• Visualizing point cloud data from multiple sensors
• Displaying seven-segment numbers

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Fixes # (issue)

Type of change

• New feature (non-breaking change which adds functionality)

Checklist

• I have read and understood the contribution guidelines
• I have run the pre-commit checks with ./isaaclab.sh --format
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• I have updated the changelog and the corresponding version in the extension's config/extension.toml file
• I have added my name to the CONTRIBUTORS.md or my name already exists there