Viewe a robot in compas_view2

1

Hi, I had an idea of visualizing a robot in compas_view2 and its trajectory, with a slider changing the state. However, I have trouble adding a robot mesh in the view.

Knowing that compas_view2 only supports compas.data.Data, I cannot add compas_fab.robots.Robot to the view, but only compas.robots.RobotModel (P.S. compas and compad_fab are a bit messy and confusing in this part of the concept for me). Yet, I still cannot put a robot mesh that moves.

  1. I load the robot and initialized the app:
from compas_view2.app import App
from compas.robots import LocalPackageMeshLoader, RobotModel
import compas_fab

viewer = App()

urdf = compas_fab.get("universal_robot/ur_description/urdf/ur5.urdf")
model = RobotModel.from_urdf_file(urdf)
loader = LocalPackageMeshLoader(compas_fab.get("universal_robot"), "ur_description")
model.load_geometry(loader)
  1. then, I try to change to model a bit, like scaling and re-configuring:
# Scale not working
model.scale(1000)

#  Configure not working
for i in range(6): model.joints[i].position = 1
  1. last, I view it by viewer. run()

image
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I can see the robot but it is always keeping this state.

I assume using compas.robots.RobotModel might not be a good idea, but I cannot figure out how to right this part of the code.

Look forward to any insight and thanks in advance.

1 Like
2

Below is the example code.


import compas_fab
from compas import json_load
from compas.robots import LocalPackageMeshLoader, RobotModel
from compas_view2.app import App


def robot_viewer(trajectory):

    viewer = App(enable_sidebar = True)

    # * Add geo to the scene -----------
    urdf = compas_fab.get("universal_robot/ur_description/urdf/ur5.urdf")
    model = RobotModel.from_urdf_file(urdf)
    loader = LocalPackageMeshLoader(compas_fab.get("universal_robot"), "ur_description")
    model.load_geometry(loader)

    model.scale(1000)
    robot_object = viewer.add(model)
    # * -------------------------------------------

    @viewer.slider(title="Trajectory", maxval=len(trajectory.points) - 1, step=1)
    def slide(value):

        robot_object.update()
        viewer.view.update()

    run = False

    @viewer.button(text="Confirm")
    def click():
        nonlocal run
        if viewer.confirm("The robot will move!") == True:
            run = True
        else:
            run = False

    viewer.run()
    if run == False:
        exit()

    return run


if __name__ == "__main__":


    trajectory = json_load(r"src\trajectory_test.json")

    run = robot_viewer( trajectory=trajectory)
3

Hey Zac,

In view2, I recommend manipulate the robot through the RobotObject which is returned by viewer.add(), The RobotModel here is purely for getting the geometry. After added into the scene, you can use .rotate_joint() function from RobotObject to update it (Assuming your trajectory is a series of FK joint rotation values). You can also move/rotate/scale the RobotObject like any other object classes in view.