Occupancy Map Generator

About

The Occupancy Map Generator Extension is used to generate a binary map of whether or not an area in the scene is occupied at a given height. It uses physics collision geometry in the Stage to determine if a location is occupied or not.

This extension is enabled by default. If it is ever disabled, it can be re-enabled from the Extension Manager by searching for omni.isaac.occupancy_map.

To access this Extension, go to the top menu bar and click Isaac Utils > Occupancy Map.

Conventions

  • All geometry must have Collisions Enabled in order to be detected by the Occupancy Map Generator. Otherwise the geometry will not appear in the final map.

  • The Start location of the map cannot be occupied.

Note

If mapping does not work correctly make sure the start location is not occupied. You can view the physics geometry by clicking the Show/Hide (eye icon) in the viewport window and selecting Show By Type -> Physics Mesh -> All

API Documentation

See the API Documentation for usage information.

User Interface

Main Occupancy Map Generator UI Window

  • Origin: An open location inside of the area you wish to map

  • Lower/Upper Bound: Areas outside of these bounds will not be mapped. These are maximal bounds, the mapped area may be smaller than these limits

  • Positioning:

    • CENTER TO SELECTION: The origin will be moved to the center of a selected prim or prims

    • BOUND SELECTION: The bounds will updated to incorporate the selected prim or prims

  • Cell Size: the number of centimeters each pixel in the final image represents

  • Use PhysX Collision Geometry: When set to True (default), the current collision approximations are used by the PhysX based lidar to generate the occupancy map. If set to False, the collision approximations are temporarily removed and the RTX Lidar uses the original triangle meshes to generate the occupancy map.

Tutorials & Examples

The following tutorials and examples showcase how to best use this extension:

Tutorials

Examples

  • Block World Generator Map: Isaac Utils -> Block World Generator Map

Block World Generator Map

The Block World Generator Map Extension converts a 2d occupancy map into a 3D block world. In this extension black pixels in the occupancy map are considered occupied and white pixels are considered free space. The generated 3D world automatically has a collision mesh applied for all the occupied pixels.

To access this Extension, go to the top menu bar and click Isaac Utils -> Block World Generator Map.

Main Block World Generator UI Window

  • Cell Size: Real-world units represented by a single pixel in the 2D occupancy image. Note that default unit in Isaac Sim is in centimeters.

  • Load : Load the desired occupancy image.

  • Generate: Button to generate the 3D block world.

Block World Usage Example

To run the Example:

  1. Save the following image to disk:

Block World Generator Example

  1. Go to the top menu bar and click Isaac Utils -> Block World Generator Map.

  2. Press the Load Image button and open the saved image. A window titled Visualization will appear.

  3. Press the Generate Block World button to create geometry corresponding to the input occupancy map in the Stage.

Block World Generator Example