ParticleNode p0 = new ParticleNode("p[0]");
ParticleNode p1 = new ParticleNode("p[1]");
ParticleNode p2 = new ParticleNode("p[2]");
visualization.addChild(elastic);
visualization.addChild(liquid);
visualization.addChild(boundary);
fluid.addChild(visualization);
visualization.setModified(true);