SHRDLU World

Small standalone tabletop blocks-world simulator. It can run as a Python object, a headless HTTP service, or a browser viewer for manual control.

Install

pip install shrdlu-world

For local development:

cd ~/shrdlu-block-world
python -m pip install -e .

Run

# Browser viewer at http://127.0.0.1:18123/
shrdlu-simulator

# Equivalent module entrypoint
python3 -m shrdlu_blocks.simulator

# API only
shrdlu-simulator --headless

# Equivalent module entrypoint
python3 -m shrdlu_blocks.simulator --headless

Useful options:

• --host HOST
• --port PORT
• --open-browser

Interface

Running python3 -m shrdlu_blocks.simulator starts a small browser UI for manual control of the scene.

The viewer includes:

• a central canvas showing the current blocks-world scene
• Select and Move modes for interacting with objects in the canvas
• zoom controls and a reset button in the top bar
• direct x and y inputs for move_grasper
• buttons for raise_grasper, lower_grasper, open_grasper, and close_grasper
• an object list for selecting the active object
• highlight and unhighlight controls for the selected object
• an event log showing recent actions and simulator responses

This UI is served from the same HTTP server as the JSON API, so the browser viewer and programmatic API stay in sync.

Python API

from shrdlu_blocks import ShrdluBlocksEnv

env = ShrdluBlocksEnv()
env.execute_action({"name": "move_grasper", "args": {"x": -0.1, "y": 0.4}})
env.execute_action({"name": "lower_grasper", "args": {}})
print(env.snapshot_text())

HTTP API

• GET /api/state
• POST /api/action
• POST /api/reset

POST /api/action expects an action object:

{
  "action": {
    "name": "move_grasper",
    "args": {"x": -0.1, "y": 0.4}
  }
}

Supported action names:

• move_grasper with x and y
• lower_grasper
• raise_grasper
• close_grasper
• open_grasper
• highlight_object
• unhighlight_object

Configuration

export SHRDLU_SIMULATOR_HOST=0.0.0.0
export SHRDLU_SIMULATOR_PORT=18123
export SHRDLU_WEB_OPEN_BROWSER=1

For remote use, forward the viewer port and open http://localhost:18123:

ssh -L 18123:localhost:18123 user@remote-host

Layout

• shrdlu_blocks/simulator/: environment, controller, scene model, and HTTP server
• shrdlu_blocks/viewer/: browser viewer and static assets
• shrdlu_blocks/client.py: small HTTP client for a running service