I'm a new user of the program. I have done a simulation of the solar system in 3 dimensions and sometimes when I rotate the view I get this error (copied from console):
Exception in thread "Thread-2" java.lang.NullPointerException at org.opensourcephysics.drawing3d.simple3d.SimpleElementTrail.computePositions(Unknown Source) at org.opensourcephysics.drawing3d.simple3d.SimpleElementTrail.processChanges(Unknown Source) at org.opensourcephysics.drawing3d.Element.processChanges(Unknown Source) at org.opensourcephysics.drawing3d.ElementTrail.processChanges(Unknown Source) at org.opensourcephysics.drawing3d.Group.processChanges(Unknown Source) at org.opensourcephysics.drawing3d.Group.processChanges(Unknown Source) at org.opensourcephysics.drawing3d.simple3d.SimpleDrawingPanel3D.paintDrawableList(Unknown Source) at org.opensourcephysics.drawing3d.simple3d.SimpleDrawingPanel3D.paintEverything(Unknown Source) at org.opensourcephysics.drawing3d.simple3d.SimpleDrawingPanel3D.render(Unknown Source) at org.opensourcephysics.drawing3d.simple3d.SimpleDrawingPanel3D.render(Unknown Source) at org.opensourcephysics.drawing3d.DrawingPanel3D.render(Unknown Source) at org.colos.ejs.library.control.drawing3d.ControlDrawingPanel3D.finalUpdate(Unknown Source) at org.colos.ejs.library.control.EjsControl.finalUpdate(Unknown Source) at org.colos.ejs.library.Animation.update(Unknown Source) at org.colos.ejs.library.Animation.step(Unknown Source) at org.colos.ejs.library.Animation.run(Unknown Source) at java.lang.Thread.run(Unknown Source)
It doesn't happen always in the same evolution step, sometimes it happens sooner and other times it takes more time to happen.
I don't know how to fix it so I would appreciate some help.
