Broken tutorial 2

TUTORIAL BROKEN FROM HERE ON

Step 2: Inserting a model programatically

To create SDF models, Revolve has sdfbuilder submodule. It defines all of the mentioned elements and makes it easy to define and nest them.

1. Replace with the following piece of code to the script:

   #!/usr/bin/env python3
   import asyncio
   import os
   import sys
   
   here = os.path.dirname(os.path.abspath(__file__))
   rvpath = os.path.abspath(os.path.join(here, '..', 'revolve'))
   sys.path.append(os.path.dirname(os.path.abspath(__file__)))
   
   from pyrevolve.gazebo.manage import WorldManager as World
   from pyrevolve.sdfbuilder import Model, Link, SDF
   from pyrevolve.sdfbuilder.math import Vector3
   
   
   async def run():
   
       world = await World.create()
       if world:
           print("Connected to the simulator world.")
       
       model = Model(
               name='sdf_model',
               static=True,
       )
       model.set_position(position=Vector3(0, 0, 1))
       link = Link('sdf_link')
       link.make_sphere(
               mass=10e10,
               radius=0.5,
       )
       link.make_color(0.7, 0.2, 0.0, 1.0)
       
       model.add_element(link)
       sdf_model = SDF(elements=[model])
       
       await world.insert_model(sdf_model)
       await world.pause(True)
       
       while True:
           await asyncio.sleep(10.0)
   
   
   def main():
       loop = asyncio.get_event_loop()
       loop.run_until_complete(run())
   
   
   if __name__ == "__main__":
       main()

2. Make sure you are using the virtual environment (.venv).

3. Run the script:

   (.venv) ./revolve.py --simulator-cmd=gazebo --manager ./tutorial2.py

The output should be:

We can see that it is not the same sphere as above. We changed the position and the colour. Take a look in the code on how it is done.

Final script

The final script should look like:

#!/usr/bin/env python3
import asyncio
import os
import sys

here = os.path.dirname(os.path.abspath(__file__))
rvpath = os.path.abspath(os.path.join(here, '..', 'revolve'))
sys.path.append(os.path.dirname(os.path.abspath(__file__)))

from pygazebo.pygazebo import DisconnectError

from pyrevolve.gazebo.manage import WorldManager as World
from pyrevolve.sdfbuilder import Model, Link, SDF
from pyrevolve.sdfbuilder.math import Vector3


async def run():
    world = await World.create()
    if world:
        print("Connected to the simulator world.")

    model = Model(
            name='sdf_model',
            static=True,
    )
    model.set_position(position=Vector3(0, 0, 1))
    link = Link('sdf_link')
    link.make_sphere(
            mass=10e10,
            radius=0.5,
    )
    link.make_color(0.7, 0.2, 0.0, 1.0)

    model.add_element(link)
    sdf_model = SDF(elements=[model])

    await world.insert_model(sdf_model)
    await world.pause(True)
    while True:
        await asyncio.sleep(10.0)


def main():
    def handler(loop, context):
        exc = context['exception']
        if isinstance(exc, DisconnectError) \
                or isinstance(exc, ConnectionResetError):
            print("Got disconnect / connection reset - shutting down.")
            sys.exit(0)
        raise context['exception']

    try:
        loop = asyncio.get_event_loop()
        loop.set_exception_handler(handler)
        loop.run_until_complete(run())
    except KeyboardInterrupt:
        print("Got Ctrl+C, shutting down.")


if __name__ == "__main__":
    main()

You can find this example with other tutorial scripts within Revolve experiments/examples directory.

This tutorial gives you some basic idea of how it all works. Now, let us insert some robots into the world!

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See next: Tutorial 3: Inserting a Robot

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