Add points into myCanvas3D (Java3D)

[Flex]

I have a canvas3d in Java3D, and I want to add some point.
I try to to this.

private void drawPoints() {
PointArray pti = new PointArray(2,PointArray.COORDINATES);
Shape3D shape = new Shape3D();
shape.removeAllGeometries();
BranchGroup ptiGroup = new BranchGroup();

pti.setCoordinate(0, new Point3d(3, 5, 23));
pti.setCoordinate(1, new Point3d(0, 5, 7));

shape.addGeometry(pti);
ptiGroup.addChild(shape);
ptiGroup.compile();
universe.addBranchGraph(ptiGroup);
}

But I don't see nothing. Why ?

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FleX