I tried making a polygon on the tree with the tree pos but it wasn't accurate and didnt cover/wrap the tree so if you want to do a bounding box or something instead it'd be something like
titan.draw(treevariable.getModel().getBoundingBox(treevariable.getGridX(), treevariable.getGridY(), treevariable.getZ()));
where titan. is my onPaint reference e.g (Graphics2D titan)
treevariable is your tree variable you get the gist
I tried mate, sorry
if you do however want to still try the polygon stuff it's
titan.draw(treevariable.getPosition().getPolygon(getBot()));