class ElasticMaterialObject(SofaObject):
def __init__(self,
attachedTo=None,
volumeMeshFileName=None,
name="ElasticMaterialObject",
rotation=[0.0, 0.0, 0.0],
translation=[0.0, 0.0, 0.0],
surfaceMeshFileName=None,
collisionMesh=None,
withConstrain=True,
surfaceColor=[1.0, 1.0, 1.0],
poissonRatio=0.3,
youngModulus=18000,
totalMass=1.0,
solver=None):
self.node = Node(attachedTo, name)
ElasticMaterialObject.createPrefab(self, volumeMeshFileName, name,
rotation, translation,
surfaceMeshFileName, collisionMesh,
withConstrain, surfaceColor,
poissonRatio, youngModulus,
totalMass, solver)
@staticmethod
def createPrefab(self,
volumeMeshFileName=None,
name="ElasticMaterialObject",
rotation=[0.0, 0.0, 0.0],
translation=[0.0, 0.0, 0.0],
surfaceMeshFileName=None,
collisionMesh=None,
withConstrain=True,
surfaceColor=[1.0, 1.0, 1.0],
poissonRatio=0.3,
youngModulus=18000,
totalMass=1.0,
solver=None):
if self.node == None:
Sofa.msg_error(
"Unable to create the elastic object because it is not attached to any node. Please fill the attachedTo parameter"
)
return None
if volumeMeshFileName == None:
Sofa.msg_error(
self.node,
"Unable to create an elastic object because there is no volume mesh provided."
)
return None
if volumeMeshFileName.endswith(".msh"):
self.loader = self.node.createObject('MeshGmshLoader',
name='loader',
filename=volumeMeshFileName,
rotation=rotation,
translation=translation)
elif volumeMeshFileName.endswith(".gidmsh"):
self.loader = self.node.createObject('GIDMeshLoader',
name='loader',
filename=volumeMeshFileName,
rotation=rotation,
translation=translation)
else:
self.loader = self.node.createObject('MeshVTKLoader',
name='loader',
filename=volumeMeshFileName,
rotation=rotation,
translation=translation)
if solver == None:
self.integration = self.node.createObject('EulerImplicit',
name='integration')
self.solver = self.node.createObject('SparseLDLSolver',
name="solver")
self.container = self.node.createObject(
'TetrahedronSetTopologyContainer', src='@loader', name='container')
self.dofs = self.node.createObject('MechanicalObject',
template='Vec3d',
name='dofs')
## To be properly simulated and to interact with gravity or inertia forces, an elasticobject
## also needs a mass. You can add a given mass with a uniform distribution for an elasticobject
## by adding a UniformMass component to the elasticobject node
self.mass = self.node.createObject('UniformMass',
totalMass=totalMass,
name='mass')
## The next component to add is a FEM forcefield which defines how the elasticobject reacts
## to a loading (i.e. which deformations are created from forces applied onto it).
## Here, because the elasticobject is made of silicone, its mechanical behavior is assumed elastic.
## This behavior is available via the TetrahedronFEMForceField component.
self.forcefield = self.node.createObject('TetrahedronFEMForceField',
template='Vec3d',
method='large',
name='forcefield',
poissonRatio=poissonRatio,
youngModulus=youngModulus)
if withConstrain:
self.node.createObject('LinearSolverConstraintCorrection',
solverName=self.solver.name)
if collisionMesh:
self.addCollisionModel(collisionMesh, rotation, translation)
if surfaceMeshFileName:
self.addVisualModel(surfaceMeshFileName, surfaceColor, rotation,
translation)
def addCollisionModel(self,
collisionMesh,
rotation=[0.0, 0.0, 0.0],
translation=[0.0, 0.0, 0.0]):
self.collisionmodel = self.node.createChild('CollisionModel')
self.collisionmodel.createObject('MeshSTLLoader',
name='loader',
filename=collisionMesh,
rotation=rotation,
translation=translation)
self.collisionmodel.createObject('TriangleSetTopologyContainer',
src='@loader',
name='container')
self.collisionmodel.createObject('MechanicalObject',
template='Vec3d',
name='dofs')
self.collisionmodel.createObject('Triangle')
self.collisionmodel.createObject('Line')
self.collisionmodel.createObject('Point')
self.collisionmodel.createObject('BarycentricMapping')
def addVisualModel(self, filename, color, rotation, translation):
self.visualmodel = VisualModel(parent=self.node,
surfaceMeshFileName=filename,
color=color,
rotation=rotation,
translation=translation)
## Add a BarycentricMapping to deform the rendering model to follow the ones of the
## mechanical model.
self.visualmodel.mapping = self.visualmodel.node.createObject(
'BarycentricMapping', name='mapping')
class ServoMotor(SofaObject):
"""A S90 servo motor
This prefab is implementing a S90 servo motor.
https://servodatabase.com/servo/towerpro/sg90
The prefab ServoMotor is composed of:
- a visual model
- a mechanical model composed two rigids. One rigid is for the motor body
while the other is implementing the servo rotating wheel.
- a KinematicMotorController to compute from an input angle the new orientation of the
servo wheel according to its parent frame.
The prefab has the following parameters:
- translation to change default location of the servo (default [0.0,0.0,0.0])
- rotation to change default rotation of the servo (default [0.0,0.0,0.0,1])
- scale to change default scale of the servo (default 1)
- doAddVisualModel to control wether a visual model is added (default True)
The prefab have the following property:
- angle use this to specify the angle of rotation of the servo motor
Example of use in a Sofa scene:
def createScene(root):
...
servo = ServoMotor(root)
## Direct access to the components
servo.node.angle = 1.0
servo.dofs.showObjects = False
## Indirect access to the components
get(servo.node, "dofs.showObjects").value = False
get(servo.node, "servowheel.dofs.showObjects").value = False
"""
def __init__(self, parent, translation=[0.0, 0.0, 0.0], rotation=[0.0, 0.0, 0.0], scale=[1.0, 1.0, 1.0], doAddVisualModel=True):
self.node = Node(parent, "ServoMotor")
self.node.addNewData("angle",
"ServoMotor Properties",
"The angular position of the motor (in radians)", "double", 0.0)
self.angle = self.node.findData("angle")
self.dofs = self.node.createObject("MechanicalObject", size=1,
name="dofs",
translation=translation, rotation=rotation, scale3d=scale,
template='Rigid3', showObject=True, showObjectScale=15)
self.servowheel = ServoWheel(self.node)
self.controller = KinematicMotorController(self.node, self.dofs, self.servowheel.dofs,
self.servowheel.node.map,
angleValue=self.angle.getLinkPath())
if doAddVisualModel:
self.addVisualModel()
def addVisualModel(self):
visual = self.node.createChild("VisualModel")
visual.createObject("MeshSTLLoader", name="loader", filename="../data/mesh/SG90_servomotor.stl")
visual.createObject("MeshTopology", src="@loader")
visual.createObject("OglModel", color=[0.15, 0.45, 0.75, 0.7], writeZTransparent=True)
visual.createObject("RigidMapping", index=0)