Place Cameras for Maximum Coverage

Purpose

Lay out infrastructure cameras across a floor area so a target fraction of it is observed, using the CameraPlacementManager API of isaacsim.sensors.rtx.placement.

Prerequisites

• Running Isaac Sim 6 / Kit 110 with python_server (port 8226); see isaac-sim-remote.
• Extension isaacsim.sensors.rtx.placement enabled (action_and_event_data_generation app, or --enable).
• Stage has the facility/environment loaded plus a baked navmesh or explicit scope=xmin,xmax,ymin,ymax.
• Shell env: $ISAAC_SIM_DIR, $ISAAC_LAB_DIR, $WORKSPACE_DIR (isaac-sim-orchestrator).

Limitations

• Does not build isaacsim.sensors.rtx.placement — consume the pin from source/apps/isaacsim.exp.action_and_event_data_generation.base.kit.
• Live Kit only; coverage uses a single focus plane at focus_height (no multi-level model).
• Greedy solver stops at ratio / budget / min_coverage_increase — not a proven minimum set.
• Cost scales with area / patch_size² (tens of seconds on large stages).
• For single-object unoccluded views (not floor coverage), use place-camera-aim-at.

Troubleshooting

Error / symptom	Cause	Solution
MAX_COVERAGE_PREFLIGHT: ext=unavailable	App does not resolve the extension	Launch isaacsim.exp.action_and_event_data_generation.base.sh, or add --enable isaacsim.sensors.rtx.placement
scope=none in preflight	No navmesh baked and no explicit scope	Bake a navmesh, or pass scope=xmin,xmax,ymin,ymax
Script raises "No cameras were authored"	Solver produced nothing	Check the console; usually a scope that misses the walkable floor, or camera_on_navmesh with no navmesh
"input section distance … is too large" warning	patch_size exceeds shorter_span / 10	Harmless — the value is auto-shrunk; pass a smaller patch_size to control it
Far fewer cameras than expected	Coverage target met early, or min_coverage_increase stopped the loop	Raise target_coverage_ratio, or raise required_camera_per_patch for redundancy
Placement never finishes on a large stage	patch_size too small for the area	Raise patch_size; cost scales with area / patch_size²
camera_info_payload.json not written	No output folder configured	Pass output_dir, which sets camera_placement_output_folder_path

When to use this skill

You want	Skill
Cover this whole floor area to a coverage ratio	this skill
N unobstructed views of this pallet / shelf / robot	place-camera-aim-at
Author a single camera's intrinsics, AOVs, distortion	isaac-camera

How the algorithm works

1. Resolve the target scope — either explicit [(x_min, x_max), (y_min, y_max)] bounds or the navmesh extents.
2. Split the scope into patch_size cells on a focus plane at focus_height, and mark which cells are accessible.
3. For each of four cardinal directions, estimate the ground-plane footprint of a candidate camera's frustum and greedily pick the pose that adds the most uncovered patches.
4. Stop when target_coverage_ratio is reached, the num_cameras budget is spent, or a new camera would add less than min_coverage_increase patches.

Full parameter semantics and the carb-settings coupling live in references/coverage-api.md; scope resolution, coverage visualisation, and the JSON payload are in references/coverage-runtime-notes.md.

Available Scripts

Script	Purpose	Arguments
scripts/place_camera_max_coverage.py	Cover a floor area with cameras using isaacsim.sensors.rtx.placement	injected key=value args (see script docstring)

Running scripts

The script is a python_server payload, not a standalone program. From agent runtimes that expose skill execution helpers, invoke it with run_script():

run_script("scripts/place_camera_max_coverage.py", args=["action=preflight"])

From a built tree, send it through the isaac-sim-remote client:

python skills/isaac-sim-remote/scripts/isaacsim_send.py \
  --file skills/place-camera-max-coverage/scripts/place_camera_max_coverage.py \
  --arg action=place --arg num_cameras=5 --arg output_dir=/tmp/isp

Workflow

1. Preflight. action=preflight (the default) reports extension, stage, and scope state without touching the stage. It never raises, so it is safe first.

   run_script("scripts/place_camera_max_coverage.py", args=["action=preflight"])
   

   Expect MAX_COVERAGE_PREFLIGHT: ext=enabled stage=ok scope=navmesh plus the resolved bounds. Resolve anything that is not ok before continuing.

2. Confirm the scope. action=scope prints the navmesh-derived bounds without placing anything. Compare them against the facility you expect — a navmesh that leaked outside the building silently wastes cameras.

   run_script("scripts/place_camera_max_coverage.py", args=["action=scope"])
   

3. Place. Either give a camera budget or let coverage drive the count.

   run_script(
       "scripts/place_camera_max_coverage.py",
       args=["action=place", "num_cameras=5", "height_range=5,7.5", "output_dir=/tmp/isp"],
   )
   

   num_cameras=-1 (the default) places until target_coverage_ratio is met. Expect MAX_COVERAGE_RESULT: placed=5 total=5 scope=... ratio=0.9 ... plus one line per new camera. The script counts prims on the stage rather than trusting the API return value.

4. Verify coverage. action=coverage debug-draws the coverage frequency of the cameras currently under the parent prim and logs the achieved coverage and full-coverage ratios to the console.

   run_script("scripts/place_camera_max_coverage.py", args=["action=coverage"])
   

5. Iterate. Vary random_seed for a different layout under the same constraints; raise required_camera_per_patch when downstream perception needs overlapping views.

Calling the API directly

from isaacsim.sensors.rtx.placement import CameraPlacementManager

manager = CameraPlacementManager.get_instance()
cameras = manager.place_camera_in_target_scope_explicit(
    target_scope=[(-9.5, 9.5), (-19.0, 0.0)],
    camera_num=5,
    target_coverage_ratio=0.9,
    camera_height_range=(5.0, 7.5),
    camera_distance_range=(8.0, 16.0),
    camera_look_down_angle_range=(20.0, 60.0),
    spawn_camera=True,
    output_camera_data=True,
)
for camera in cameras or []:
    print(camera["translate"], camera["rotation"])

Two traps worth stating up front:

• output_camera_data defaults to False, and the call returns None in that case even on success. Pass True when you want the poses back.
• Exceptions are swallowed into carb.log_error and the call then returns a partially filled list. Verify against the stage, not the return value — which is what scripts/place_camera_max_coverage.py does.

Use place_camera_in_target_scope_explicit, not place_camera_in_target_scope. The latter is the GUI path and reads every parameter from persistent carb settings.

Related skills

• isaac-sim-remote — the transport this skill's script rides on.
• place-camera-aim-at — the single-target sibling.
• occupancy-map — an alternative source of floor bounds when no navmesh exists.
• isaac-camera — per-camera intrinsics, render products, AOVs, distortion.
• isaac-sim-sensor — attaching annotators and writers once cameras exist.