question: elastic model explodes when youngs modulus is too high

[Ray0716]

i'm trying to import an obj model and simluate it with a soft elastic material. here's my code:

`import genesis as gs

########################## init ##########################
gs.init()
cam_record = False # Set to True to record the camera output

########################## create a scene ##########################

scene = gs.Scene(
sim_options=gs.options.SimOptions(
dt = 4e-3,
substeps = 10,
),
mpm_options=gs.options.MPMOptions(
lower_bound = (-1.5, -1.5, 0.0),
upper_bound = (1.5, 1.5, 1),
),
vis_options=gs.options.VisOptions(
visualize_mpm_boundary = True,
),
viewer_options=gs.options.ViewerOptions(
camera_fov=30,
),
show_viewer = True,
)

########################## entities ##########################
plane = scene.add_entity(
morph=gs.morphs.Plane(),
)

obj_plastic = scene.add_entity(
material=gs.materials.MPM.Elastic(E=1e7, nu=1e-11, rho=10000),
morph=gs.morphs.Mesh(
file="objects/compliant_clip.obj",
scale=10,
pos=(0.0, 0.0, 0.5), # Drop it from 0.5 meters high
euler=(90, 180, 90)
),
surface=gs.surfaces.Default(
color = (0.4, 1.0, 0.4),
vis_mode = 'visual',
),
)

########################## build ##########################
if cam_record:
cam = scene.add_camera(
res=(640, 480),
pos=(3.5, 0.0, 2.5),
lookat=(0, 0, 0.5),
fov=30,
GUI=False # <--- disable built-in GUI so you can handle OpenCV manually
)
scene.build()
if cam_record:
cam.start_recording()

horizon = 300
for i in range(horizon):
scene.step()
if cam_record:
cam.render()
if cam_record:
cam.stop_recording(save_to_filename='compliantDrop.mp4', fps=30)
`

the problem is that i need this to be stiffer, so i need to increase the youngs modulus (e) , however when i increase it it gets really big and then dissapears. does anyone know why this happens?