Supervisor return None object on 2023 version #6174
Description
Hi,
i'm using Webots 2023a under Ubuntu 22 LST, I'm trying to use Supervisor based on the tutorial code, I'm getting this output:
traceback (most recent call last):
File "C:\Users\Admin\Documents\my_project\controllers\my_controller_sup\my_controller_sup.py", line 10, in <module>
trans_field = robot_node.getField("translation")
AttributeError: 'NoneType' object has no attribute 'getField'
WARNING: 'my_controller_sup' controller exited with status: 1.
i noticed that robot_node is None !!
the used code is:
from math import sqrt
from controller import Supervisor
TIME_STEP = 32
supervisor = Supervisor()
# get handle to robot's translation field
robot_node = supervisor.getFromDef("e-puck")
trans_field = robot_node.getField("translation")
for a in range(0, 25):
for b in range(0, 33):
# evaluate robot during 60 seconds (simulation time)
t = supervisor.getTime()
while supervisor.getTime() - t < 60:
# perform robot control according to a, b
# (and possibly t) parameters.
# controller termination
if supervisor.step(TIME_STEP) == -1:
quit()
# compute travelled distance
values = trans_field.getSFVec3f()
dist = sqrt(values[0] * values[0] + values[2] * values[2])
print("a=%d, b=%d -> dist=%g" % (a, b, dist))
# reset robot position and physics
INITIAL = [0, 0.5, 0]
trans_field.setSFVec3f(INITIAL)
robot_node.resetPhysics()