fix: hide xy-plane indicator

src/adapptlet.civet

@@ -50,6 +50,11 @@ function postApplets(jApplets: AppletDescription[], codebase = '')
             if config3d
                worked := api.enable3D true
                api.setPerspective 'T'
+               // Get rid of the xy-plane indicator
+               xml .= api.getXML()
+               xml = xml.replace /plate.show="\w+"/, 'plate show="false"'
+               console.log 'Trying', xml
+               api.setXML xml
             else
                api.setPerspective 'G'
             for name, value in jApp.params
@@ -64,6 +69,7 @@ function postApplets(jApplets: AppletDescription[], codebase = '')
                   -depth - 10, depth + 10,
                   false
                api.setAxesVisible 3, false, false, false
+               api.setGridVisible 3, false
             else
                api.setCoordSystem -10, 10 + jApp.width, -10, 10 + jApp.height
                api.setAxesVisible false, false
@@ -612,9 +618,9 @@ classHandler: Record<JoyceClass, ClassHandler> :=
                // https://www.reddit.com/r/geogebra/comments/12cbr85/setlineopacity_command/
                // I don't really understand how/why it works, but it seems to
                // So that's good enough for me
-               xml := api.getXML name
-               xml.replace(/opacity="\d+"/, 'opacity="0"')
-               api.evalXML(xml)
+               xml .= api.getXML name
+               xml = xml.replace /opacity="\d+"/, 'opacity="0"'
+               api.evalXML xml
                // This last step is especially confusing... I think
                // evaluating the modified XML created a sort of second
                // copy of the entity, and so we have to hide the original one