public void calcForce() {
		for(Physics p: simulators) {
			if(p instanceof PhysicsGravity) {
				MassObject3D mo;
				arguments = new double[sourceGravity[numObjs]];
				dist = new SimpleVector[sourceGravity[numObjs]];
				for(int j = 0; j < sourceGravity[numObjs]; j++) {
					mo = (MassObject3D)objects.get(sourceGravity[j]);
					arguments[j] = mo.getMass();
					dist[j] = mo.getTransformedCenter();
				}
				for(int k = 0; k < gravityInteraction[numObjs]; k++) {
					mo = (MassObject3D)objects.get(gravityInteraction[k]);
					ownParam = mo.getMass();
					p.setParam(ownParam, arguments, dist, mo.getTransformedCenter());
					p.calcTotalForce();
					mo.calcAcceleration(p.getTotalForce());
                    p.reset();
				}
			}
			p.reset();
		}
		
	}