def createGridScene(rootNode, startPoint, endPoint, numX, numY, numZ,
totalMass, stiffnessValue, dampingRatio):
# The graph root node
rootNode.setGravity(Sofa.Vector3(0, -10, 0))
rootNode.dt = 0.01
rootNode.createObject(
'VisualStyle',
displayFlags=
'hideVisual showBehavior hideCollision showMapping hideOptions')
simulatedScene = rootNode.createChild('simulatedScene')
eulerImplicitSolver = simulatedScene.createObject('EulerImplicitSolver')
cgLinearSolver = simulatedScene.createObject('CGLinearSolver')
# The rigid object
rigidNode = simulatedScene.createChild('rigidNode')
rigid_dof = rigidNode.createObject('MechanicalObject',
template='Rigid',
name='rigidNode_dof')
rigid_mass = rigidNode.createObject('UniformMass',
template='Rigid',
name='rigidNode_mass')
rigid_fixedConstraint = rigidNode.createObject(
'FixedConstraint', template='Rigid', name='rigidNode_fixedConstraint')
# Particles mapped to the rigid object
mappedParticles = rigidNode.createChild('mappedParticles')
mappedParticles_dof = mappedParticles.createObject(
'MechanicalObject', name='mappedParticles_dof')
mappedParticles_mapping = mappedParticles.createObject(
'RigidMapping',
template='Rigid',
name='mappedParticles_mapping',
input='@./../rigidNode_dof',
output='@./mappedParticles_dof')
# // The independent particles
independentParticles = simulatedScene.createChild('independentParticles')
independentParticles_dof = independentParticles.createObject(
'MechanicalObject', name='independentParticles_dof')
# // The deformable grid, connected to its 2 parents using a MultiMapping
deformableGrid = independentParticles.createChild(
'deformableGrid') # first parent
mappedParticles.addChild(deformableGrid) # second parent
deformableGrid_grid = deformableGrid.createObject(
'RegularGridTopology', name='deformableGrid_grid')
deformableGrid_grid.setNumVertices(numX, numY, numZ)
deformableGrid_grid.setPos(startPoint.x, endPoint.x, startPoint.y,
endPoint.y, startPoint.z, endPoint.z)
deformableGrid_dof = deformableGrid.createObject('MechanicalObject',
name='deformableGrid_dof')
# deformableGrid_mapping = mappedParticles.createObject('SubsetMultiMapping', template='Vec3d,Vec3d', name='mapping', input='@../../simulatedScene/independentParticles/independentParticles_dof @./mappedParticles_dof', output='@../../simulatedScene/independentParticles/deformableGrid/deformableGrid_dof')
deformableGrid_mapping = deformableGrid.createObject(
'SubsetMultiMapping',
template='Vec3d,Vec3d',
name='mapping',
input=
'@/simulatedScene/independentParticles/independentParticles_dof @/simulatedScene/rigidNode/mappedParticles/mappedParticles_dof',
output='@./deformableGrid_dof')
mass = deformableGrid.createObject('UniformMass',
template='Vec3d',
name='deformableGrid_mass')
mass.mass = totalMass / (numX * numY * numZ)
hexaFem = deformableGrid.createObject('HexahedronFEMForceField',
template='Vec3d',
name='deformableGrid_hexaFEM')
hexaFem.youngModulus = 1000
hexaFem.poissonRatio = 0.4
# // ====== Set up the multimapping and its parents, based on its child
deformableGrid_grid.init(
) # initialize the grid, so that the particles are located in space
deformableGrid_dof.init() # create the state vectors
xgrid = deformableGrid_dof.position # xgrid = deformableGrid_dof.readPositions() # cerr<<"xgrid = " << xgrid << endl;
# xgrid is not the positions vector of the dof, but a copy of it
# // create the rigid frames and their bounding boxes
numRigid = 2
boxes = [] # vector<BoundingBox> boxes(numRigid);
indices = [
[], []
] # vector< vector<unsigned> > indices(numRigid); // indices of the particles in each box
eps = (endPoint.x - startPoint.x) / (numX * 2.0)
# // first box, x=xmin
boxes.append(
BoundingBox(
Sofa.Vector3(startPoint.x - eps, startPoint.y - eps,
startPoint.z - eps),
Sofa.Vector3(startPoint.x + eps, endPoint.y + eps,
endPoint.z + eps)))
# // second box, x=xmax
boxes.append(
BoundingBox(
Sofa.Vector3(endPoint.x - eps, startPoint.y - eps,
startPoint.z - eps),
Sofa.Vector3(endPoint.x + eps, endPoint.y + eps,
endPoint.z + eps)))
rigid_dof.resize(numRigid)
# MechanicalObjectRigid3d::WriteVecCoord xrigid = rigid_dof->writePositions();
# for xrigid, we create a list of 7-coords lists (position+orientation), then we will copy it in rigid_dof.position when we are done
xrigid = []
xrigid.append([
startPoint.x, 0.5 * (startPoint.y + endPoint.y),
0.5 * (startPoint.z + endPoint.z), 0, 0, 0, 1
])
xrigid.append([
endPoint.x, 0.5 * (startPoint.y + endPoint.y),
0.5 * (startPoint.z + endPoint.z), 0, 0, 0, 1
])
rigid_dof.position = xrigid
# // find the particles in each box
isFree = [True] * len(xgrid)
numMapped = 0
for i in range(len(xgrid)):
for b in range(numRigid):
if isFree[i] and boxes[b].contains(xgrid[i]):
indices[b].append(i) # associate the particle with the box
isFree[i] = False
numMapped = numMapped + 1
# // distribution of the grid particles to the different parents (independent particle or solids.
parentParticles = [None] * len(
xgrid
) # vector< pair<MechanicalObject3d*,unsigned> > parentParticles(xgrid.size());
# // Copy the independent particles to their parent DOF
independentParticles_dof.resize(numX * numY * numZ - numMapped)
xindependent = independentParticles_dof.position # MechanicalObject3::WriteVecCoord xindependent = independentParticles_dof->writePositions(); // parent positions
independentIndex = 0
for i in range(len(xgrid)):
if isFree[i]:
parentParticles[i] = [independentParticles_dof, independentIndex]
xindependent[independentIndex] = xgrid[i]
independentIndex = independentIndex + 1
independentParticles_dof.position = xindependent
# // Mapped particles. The RigidMapping requires to cluster the particles based on their parent frame.
mappedParticles_dof.resize(numMapped)
# print 'numMapped='+str(numMapped)
xmapped = mappedParticles_dof.position # MechanicalObject3::WriteVecCoord xmapped = mappedParticles_dof->writePositions(); // parent positions
print 'xmapped size = ' + str(len(xmapped))
mappedParticles_mapping.globalToLocalCoords = True # to define the mapped positions in world coordinates
pointsPerFrame = [
] # vector<unsigned>* pointsPerFrame = mappedParticles_mapping->pointsPerFrame.beginEdit(); // to set how many particles are attached to each frame
mappedIndex = 0
print 'len(indices)=' + str(len(indices))
# print 'indices='+str(indices)
for ind in indices:
print 'len(ind)=' + str(len(ind))
pointsPerFrame.append(
len(ind)
) # Tell the mapping the number of points associated with this frame. One box per frame
for i in ind:
print 'i=' + str(i) + ' mappedIndex=' + str(mappedIndex)
parentParticles[i] = [mappedParticles_dof, mappedIndex]
# print 'xgrid[i]'+str(xgrid[i])
xmapped[mappedIndex] = xgrid[i]
mappedIndex = mappedIndex + 1
mappedParticles_dof.position = xmapped
print 'repartition=' + str(mappedParticles_mapping.repartition)
mappedParticles_mapping.findData('repartition').setSize(
len(pointsPerFrame))
mappedParticles_mapping.repartition = pointsPerFrame
# // Declare all the particles to the multimapping
for pp in parentParticles:
deformableGrid_mapping.addPoint(pp[0], pp[1])
def createScene(rootNode):
createGridScene(rootNode, Sofa.Vector3(0, 0, 0), Sofa.Vector3(5, 1, 1), 6,
2, 2, 1.0, 100.0, 0.0)
return rootNode