Inertia Error

main.py

import os
from pydrake.all import (
	StartMeshcat,
	DiagramBuilder,
	AddMultibodyPlantSceneGraph,
	Parser,
	LoadModelDirectivesFromString,
	ProcessModelDirectives,
)

directives_str = """directives:
- add_model:
    name: tets
    file: package://symmetries/test.obj
"""

meshcat = StartMeshcat()
builder = DiagramBuilder()
plant, scene_graph = AddMultibodyPlantSceneGraph(builder, time_step=0.0)

parser = Parser(plant)
parser.package_map().Add("symmetries", os.getcwd())
directives = LoadModelDirectivesFromString(directives_str)
models = ProcessModelDirectives(directives, plant, parser)

plant.Finalize()
diagram = builder.Build()

package.xml

<?xml version="1.0"?>
<package format="2">
  <name>symmetries</name>
  <version>0.0.0</version>
</package>

test.obj

g test

v 0.000000 0.000000 0.500000
v 0.000000 0.000000 -0.500000
v 0.000000 1.000000 0.500000
v 0.000000 1.000000 -0.500000
v 1.000000 0.000000 0.500000
v 1.000000 0.000000 -0.500000

f 1 3 5
f 2 4 6
f 1 2 3
f 2 3 4
f 3 4 5
f 4 5 6
f 5 6 1
f 6 1 2