# encoding: utf-8
# 2013 © Václav Šmilauer <eu@doxos.eu>
import unittest
from minieigen import *
import woo.core
import woo.dem
import woo.utils
import math
from woo.dem import *
[docs]class TestEllipsoid(unittest.TestCase):
'Test :obj:`Cg2_Ellipsoid_Ellipsoid_L6Geom`.'
[docs] def setUp(self):
S=self.S=woo.core.Scene(fields=[woo.dem.DemField()])
self.mat=FrictMat(density=1e3,young=1e8,ktDivKn=.2,tanPhi=.5)
S.dtSafety=0.7
S.engines=[Leapfrog(reset=True,damping=.4),InsertionSortCollider([Bo1_Ellipsoid_Aabb()],verletDist=0.),ContactLoop([Cg2_Ellipsoid_Ellipsoid_L6Geom()],[Cp2_FrictMat_FrictPhys()],[Law2_L6Geom_FrictPhys_IdealElPl(noBreak=True)])]
#,DynDt(stepPeriod=1000)]
#woo.utils.defaultEngines(damping=.0,cp2=Cp2_FrictMat_HertzPhys(gamma=0,en=0,label='cp2',poisson=.2),law=Law2_L6Geom_HertzPhys_DMT(),dynDtPeriod=10)+[
# -123 is replaced by v0 before actually used
# LawTester(ids=(0,1),abWeight=.5,stages=[LawTesterStage(values=(-123,0,0,0,0,0),whats='ivv...',until='stage.rebound',done='S.stop(); tester.dead=True')],label='tester')
#]
[docs] def testNormalDisplacementEllipsoid(self):
'Ellipsoid: normal displacement on contact with ellipsoid.'
self.S.saveTmp()
# try the same thing with different sizes of ellipsoids
# divide by 3. so that number are nice (initial distance is .1+.2=.3)
for scale in [.5/3.,1./3.,10./3.,100./3.,1000/3.]:
S=woo.core.Scene.loadTmp()
# two ellipsoids exteranlly touching perpendicularly; the whole setup it rotated by gOri
gOri=Quaternion((.1,1,.3),math.pi/3.) # some rather random orientation
gOri.normalize() # important; axis is normalized automatically in minieigen newly, but not yet always
S.dem.par.add([
woo.dem.Ellipsoid.make((0,0,0),semiAxes=scale*Vector3(.1,.2,.1),ori=gOri,mat=self.mat,fixed=True),
woo.dem.Ellipsoid.make(gOri*(scale*Vector3(.3,0,0)),semiAxes=scale*Vector3(.2,.1,.1),ori=gOri,mat=self.mat,fixed=True)
],nodes=True) # velocity is assigned to the second ellipsoid below, nodes=True needed
e0,e1=S.dem.par[0],S.dem.par[1]
d0,d1=e0.shape.nodes[0].dem,e1.shape.nodes[0].dem
e1.vel=gOri*Vector3(-.1,0,0)
S.dt=.1
if 0: # debugging stuff
l0=scale*(.1+.2)
print()
print('distance',(S.dem.par[0].pos-S.dem.par[1].pos).norm())
print('distance',l0)
S.one()
C=S.dem.con[0]
if 0: # debugging stuff
print(C, C.geom.uN)
l=(S.dem.par[0].pos-S.dem.par[1].pos).norm()
print('distance after',l)
print(S.dem.par[0].pos, S.dem.par[1].pos, 'dist',l0,l)
print('displacement',l-l0)
print('displacement',C.geom.uN)
# e1 should move by -.1×.1 = .01 towards the first one, which should be the overlap distance
self.assertAlmostEqual(C.geom.uN,-.01,delta=1e-5*0.01)
[docs] def testNormalDisplacementWall(self):
'Ellipsoid: normal displacement on contact with wall'
pass
#self.S.saveTmp()
#for scale in [.1,1.,10.]:
# gOri=Quaternion((1,2,3),math.pi/4.) # some random orientation
[docs] def testMassInertia(self):
'Ellipsoid: mass and inertia computation'
a,b,c=1,2,3
rho=1
e=Ellipsoid.make(center=(0,0,0),semiAxes=(a,b,c),mat=FrictMat(density=rho))
m=rho*(4/3.)*math.pi*a*b*c
I=(1/5.)*m*Vector3(b**2+c**2,a**2+c**2,a**2+b**2)
self.assertAlmostEqual(e.mass,m)
self.assertAlmostEqual(e.inertia,I)