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[Luc OGER <question682290@xxxxxxxxxxxxxxxxxxxxx>]

New question #682290 on Yade:
https://answers.launchpad.net/yade/+question/682290

Hello,

 I am trying to setup properly the possible interaction between different group of sphere: some can interact with other, some cannot interact with themselves

here the basic code
# basic simulation showing sphere falling ball gravity,
# bouncing against another sphere representing the support

# DATA COMPONENTS

# add 2 particles to the simulation
# they the default material (utils.defaultMat)
mask1=0b10
mask2=0b01
mask3=0b11

O.bodies.append([
	# fixed: particle's positionin space will not change (support)
	sphere(center=(0,0,0),radius=.5,fixed=True,mask=mask1,color=(0,0,1)),		#fond immobile
	sphere(center=(0,0,2),radius=.5,fixed=False,mask=mask2,color=(0,1,0)),
        # these particles are free, subject to dynamics
	sphere(center=(0,0,4),radius=.5,fixed=False,mask=mask3,color=(1,0,0)),
	sphere(center=(0,0,6),radius=.5,fixed=False,mask=mask3,color=(1,0,0)),
        # fixed: particle's positionin space will not change (support)
        sphere(center=(3,0,0),radius=.5,fixed=True,mask=mask1,color=(0,0,1)),           #fond immobile
        sphere(center=(3,0,2),radius=.5,fixed=False,mask=mask3,color=(1,0,0)),
        # these particles are free, subject to dynamics
        sphere(center=(3,0,4),radius=.5,fixed=False,mask=mask2,color=(0,1,0)),
        sphere(center=(3,0,6),radius=.5,fixed=False,mask=mask2,color=(0,1,0)),
        # fixed: particle's positionin space will not change (support)
        sphere(center=(6,0,0),radius=.5,fixed=True,mask=mask3,color=(1,0,0)),           #fond immobile
        sphere(center=(6,0,2),radius=.5,fixed=False,mask=mask1,color=(0,0,1)),
        # these particles are free, subject to dynamics
        sphere(center=(6,0,4),radius=.5,fixed=False,mask=mask3,color=(1,0,0)),
        sphere(center=(6,0,6),radius=.5,fixed=False,mask=mask2,color=(0,1,0)),
        # fixed: particle's positionin space will not change (support)
        sphere(center=(9,0,0),radius=.5,fixed=True,mask=mask2,color=(0,1,0)),           #fond immobile
        sphere(center=(9,0,2),radius=.5,fixed=False,mask=mask1,color=(0,0,1)),
        # these particles are free, subject to dynamics
        sphere(center=(9,0,4),radius=.5,fixed=False,mask=mask3,color=(1,0,0)),
        sphere(center=(9,0,6),radius=.5,fixed=False,mask=mask2,color=(0,1,0)),
        # fixed: particle's positionin space will not change (support)
        sphere(center=(12,0,0),radius=.5,fixed=True,mask=mask1,color=(0,0,1)),           #fond immobile
        sphere(center=(12,0,2),radius=.5,fixed=False,mask=mask1,color=(0,0,1)),
        # these particles are free, subject to dynamics
        sphere(center=(12,0,4),radius=.5,fixed=False,mask=mask3,color=(1,0,0)),
        sphere(center=(12,0,6),radius=.5,fixed=False,mask=mask2,color=(0,1,0)),






])

# FUNCTIONAL COMPONENTS
collider.avoidSelfInteractionMask = 0b00


# simulation loop -- see presentation for the explanation
O.engines=[
	ForceResetter(),
	InsertionSortCollider([Bo1_Sphere_Aabb()]),
	InteractionLoop(
		[Ig2_Sphere_Sphere_ScGeom()],        # collision geometry
		[Ip2_FrictMat_FrictMat_FrictPhys()], # collision "physics"
		[Law2_ScGeom_FrictPhys_CundallStrack()]   # contact law -- apply forces
	),
	# Apply gravity force to particles. damping: numerical dissipation of energy.
	NewtonIntegrator(gravity=(0,0,-9.81),damping=0.1)
	
]

# set timestep to a fraction of the critical timestep
# the fraction is very small, so that the simulation is not too fast
# and the motion can be observed
O.dt=.5e-4*PWaveTimeStep()

# save the simulation, so that it can be reloaded later, for experimentation
O.saveTmp()

so the three masks are :
mask1=0b10	blue
mask2=0b01	green
mask3=0b11	red

and the result for  collider.avoidSelfInteractionMask
0b00	full interaction
0b01	full no interaction
0b10	full interaction
0b11	full no interaction

 according to the definiton of the mask "This mask is used to avoid the interactions inside a group of particles. To do so, the particles must have the exact same mask and that mask should have one bit in common with this avoidSelfInteractionMask as for their binary representations" this should not be ful or zero interactions???

where I made a mistake?


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