show_me¶

Submodules¶

Classes¶

class brom_drake.productions.debug.show_me.show_me_system.ShowMeSystem(plant: MultibodyPlant, model_index: ModelInstanceIndex, desired_joint_positions: ndarray, **kwargs)[source]¶

Description

This class defines a LeafSystem that will force a specific model (model_index) in a MultibodyPlant to hold the joint positions provided to it as input.

The object may or may not be welded to the world frame.

Block Diagram

The ShowMeSystem block diagram is as follows:

                            |---------------|
                            |               |
desired_joint_positions --->| ShowMeSystem  |---> measured_joint_positions
                            |               |
                            |---------------|

Parameters

plantMultibodyPlant: The MultibodyPlant containing the model to be shown.
model_indexModelInstanceIndex: The ModelInstanceIndex of the model to be shown.
desired_joint_positionsnp.ndarray: The desired joint positions for the model, if any.

SetModelJointPositions(context: Context, output: BasicVector)[source]¶

Description

This method will set the joint positions of the model to the desired joint positions.

Parameters

context: Context: The context of the LeafSystem at the time that this callback is triggered.
output: BasicVector: The output vector to be populated with the current joint positions.

class brom_drake.productions.debug.show_me.show_me_this_model.ShowMeThisModel(path_to_model: str | Path, with_these_joint_positions: List[float] = None, base_link_name: str = None, time_step: float = 0.001, meshcat_port_number: int = 7001, show_collision_geometries: bool = False, **kwargs)[source]¶

Description

A production which allows the user to visualize a specified model in Meshcat, with the ability to set desired joint positions, if the model is a robot/articulated.

Parameters

path_to_model: str: The path to the model file to be visualized. TODO: Add support for Path type. Make sure to add tests!!
with_these_joint_positions: List[float], optional: A list of joint positions to set the model to when visualized. The length of this list must match the number of positions in the model. If None, the model will be visualized in its default configuration. Default is None.
base_link_name: str, optional: The name of the base link of the model. If None, the production will attempt to automatically determine the base link name. Default is None.
time_step: float, optional: The time step to use for the MultibodyPlant. Default is 1e-3.
meshcat_port_number: int, optional: The port number to use for Meshcat visualization. If None, Meshcat visualization will be disabled. Default is 7001.
show_collision_geometries: bool, optional: A boolean flag indicating whether to show collision geometries in Meshcat INSTEAD of the visual geometries. Default is False.

Usage

The production can be used to show both simple models (e.g., single objects) or articulated models (e.g., robots).

To show a simple model, simply provide the path to the model file.

from brom_drake.productions import ShowMeThisModel

# Some stuff here

urdf_file_path = "path/to/your/model.urdf"

# Create the production
production = ShowMeThisModel(
    urdf_file_path,
    time_step=1e-3,
)

# Add the cast to the production, build the diagram, and simulate
diagram, diagram_context = production.add_cast_and_build()

# Set up simulation
simulator = Simulator(diagram, diagram_context)
simulator.set_target_realtime_rate(1.0)
simulator.set_publish_every_time_step(False)

If the model is articulated, then you can also provide desired joint positions.

from brom_drake.productions import ShowMeThisModel

# Some stuff here

urdf_file_path = "path/to/your/articulated_model.urdf"
desired_joint_positions = [0.0, 1.0, -1.0, 0.5]  # Example joint positions

# Create the production
production = ShowMeThisModel(
    urdf_file_path,
    with_these_joint_positions=desired_joint_positions,
    time_step=1e-3,
)

# Add the cast to the production, build the diagram, and simulate
diagram, diagram_context = production.add_cast_and_build()

# Set up simulation
simulator = Simulator(diagram, diagram_context)
simulator.set_target_realtime_rate(1.0)
simulator.set_publish_every_time_step(False)

add_cast_and_build(cast: Tuple[Role, LeafSystem | Diagram] = []) → Tuple[Diagram, Context][source]¶

Description

This method builds the production’s diagram and context, and assigns the plant context to the internal ShowMeSystem.

Parameters

cast: Tuple[Role, Performer], optional: The cast to be added to the production. Default is an empty tuple.

Returns

diagram: Diagram: The built Diagram of the production.
diagram_context: Context: The built Context of the production.

add_multibody_triads()[source]¶

Description

This method will add triads to the world frame and any other relevant frames.

add_supporting_cast()[source]¶

Description

This method updates the production’s - MultibodyPlant with the user’s model - Using the ShowMeSystem to freeze the model in place - Connects to Meshcat, if requested

This is required to be implemented by all children of the BaseProduction class.

create_and_connect_source_of_joint_positions()[source]¶

Description

This method will create and connect a source of joint positions to the ShowMeSystem.

Assumptions

self.show_me_system is not None
self.q_des is not None

find_number_of_positions_in_model() → int[source]¶

Description

This method will return the number of positions in the model as defined by the user (through the path_to_model).

Returns

n_positions: int: The number of positions in the model.

property id: ProductionID¶

Description

This property returns the unique identifier for this production. (i.e., ProductionID.kShowMeThisModel)

This is required to be implemented by all children of the BaseProduction class.

Returns

id: ProductionID: The unique identifier for this production.

property suggested_roles: List[Role]¶

Description

This property returns an empty list, because there are no suggested roles for this production.

This is required to be implemented by all children of the BaseProduction class.

Returns

roles: List[Role]: A list of suggested roles for this production.

Functions¶

(None found)

Variables¶

(None found)