def make_body_from_name(partname, root_transformation):
shape1 = TopoDS.TopoDS_Shape()
if (mydoc.GetNamedShape(shape1, partname)):
# Make a ChBody representing the TopoDS_Shape part from the CAD:
mbody1 = cascade.ChBodyEasyCascade(shape1, # shape
1000, # density (center of mass & inertia automatically computed)
True, # mesh for visualization?
False) # mesh for collision?
mysystem.Add(mbody1)
# Move the body as for global displacement/rotation (also mbody1 %= root_frame; )
mbody1.ConcatenatePreTransformation(root_transformation)
return mbody1
else:
raise ValueError("Warning. Body part name cannot be found in STEP file.\n")
# Set the global collision margins. This is expecially important for very large or
# very small objects. Set this before creating shapes. Not before creating mysystem.
chrono.ChCollisionModel.SetDefaultSuggestedEnvelope(0.001)
chrono.ChCollisionModel.SetDefaultSuggestedMargin(0.001)
# create a 3dCAD shape using the OCC OpenCascade API (a torus cut by a cylinder)
my_torus = BRepPrimAPI.BRepPrimAPI_MakeTorus(0.1, 0.02).Shape()
my_cylinder = BRepPrimAPI.BRepPrimAPI_MakeCylinder(0.09, 0.1).Shape()
my_shape = BRepAlgoAPI.BRepAlgoAPI_Cut(my_torus, my_cylinder).Shape()
# use it to make a body with proper center of mass and inertia tensor,
# given the CAD shape. Also visualize it.
my_body = cascade.ChBodyEasyCascade(
my_shape, # the CAD shape
1000, # the density
True, # must collide using the triangle mesh geometry?
True) # must be visualized?
mysystem.Add(my_body)
# Create a large cube as a floor.
my_floor = chrono.ChBodyEasyBox(1, 0.2, 1, 1000, True)
my_floor.SetPos(chrono.ChVectorD(0, -0.3, 0))
my_floor.SetBodyFixed(True)
mysystem.Add(my_floor)
my_color = chrono.ChColorAsset(0.2, 0.2, 0.5)
my_floor.AddAsset(my_color)
# ---------------------------------------------------------------------
tot_rotation = rotation2 % rotation1 # rotate on 1 then on 2, using quaternion product
root_frame = chrono.ChFrameMovingD(chrono.ChVectorD(0, 0, 0), tot_rotation)
# Retrieve some sub shapes from the loaded model, using
# the GetNamedShape() function, that can use path/subpath/subsubpath/part
# syntax and * or ? wildcards, etc.
mrigidBody1 = 0
mrigidBody2 = 0
if load_ok:
shape1 = TopoDS.TopoDS_Shape()
if (mydoc.GetNamedShape(shape1, "Assem1/body1")):
mbody1 = cascade.ChBodyEasyCascade(shape1, 1000) # density
mysystem.Add(mbody1)
mbody1.SetBodyFixed(True)
# Move the body as for global displacement/rotation (also mbody1 %= root_frame; )
mbody1.ConcatenatePreTransformation(root_frame)
mrigidBody1 = mbody1
else:
print("Warning. Desired object not found in document \n")
shape2 = TopoDS.TopoDS_Shape()
if (mydoc.GetNamedShape(shape2, "Assem1/body2")):
my_material = chrono.ChMaterialSurfaceNSC()
my_material.SetFriction(0.5)
# create a 3dCAD shape using the OCC OpenCascade API (a torus cut by a cylinder)
my_torus = BRepPrimAPI.BRepPrimAPI_MakeTorus(0.1,0.02).Shape()
my_cylinder = BRepPrimAPI.BRepPrimAPI_MakeCylinder(0.09,0.1).Shape()
my_shape = BRepAlgoAPI.BRepAlgoAPI_Cut(my_torus, my_cylinder).Shape()
# use it to make a body with proper center of mass and inertia tensor,
# given the CAD shape. Also visualize it.
my_tolerance = cascade.ChCascadeTriangulateTolerances(0.1 ,True,0.5)
my_body = cascade.ChBodyEasyCascade(my_shape,# the CAD shape
1000, # the density
my_tolerance, # must visualize triangle mesh geometry?
True, # must collide?
my_material) # collision material
mysystem.Add(my_body)
# Create a large cube as a floor.
my_floor = chrono.ChBodyEasyBox(1, 0.2, 1, # x y z size
1000, # density
True, # must visualize?
True, # must collide?
my_material) # collision material
my_floor.SetPos(chrono.ChVectorD(0,-0.3,0))
my_floor.SetBodyFixed(True)
mysystem.Add(my_floor)