How to change Select 3D Object behavior with 3D Javascript

You do it by turning off the default selection handler, then adding a mouse event handler which scans the objects under the cursor and does "something" with them (change render mode, wave a flag, whatever...)

Simple example that opens an alert when you click something - paste this into a .js file and load as the embedded script of a 3D annotation:



// start of script example

runtime.overrideSelection = true;
var myMouseHandler = function( event ) {
if ( event.isMouseUp ) {
var myMesh = null;
if ( event.hits.length > 0 ) myMesh = event.hits[0].target;
if ( myMesh != null ) {
// do your selection-based stuff here
host.app.alert("You clicked on " + myMesh.name);
}
}
}

var mouseEventHandler = new MouseEventHandler();
mouseEventHandler.onMouseDown = false;
mouseEventHandler.onMouseMove = false;
mouseEventHandler.onMouseUp = true;
mouseEventHandler.onEvent = myMouseHandler;
runtime.addEventHandler( mouseEventHandler );

// end of script example

Thanks for the quick reply.

I tested it and it works great for selection in the 3D Annot window.

I guess I will need to override the selection handler in the product structure browser in the model tree pane as well somehow as it still produces the default selection behavior.

Is that possible?

Selections in the 3D API are strange things, disabling the default "selection" handler refers only to events tunneled from the mouse event handler (hence why you can replace it with one of those). If you want to *observe* selection events from everywhere (including the model tree) then register a SelectionEventHandler() function in the same way as the mouseEventHandler example:


var mySelectionHandler = function( event ) {
if ( event.selected ) host.app.alert("SelectionHandler says you clicked on " + event.node.name);
}



var selectionHandler = new SelectionEventHandler();
selectionHandler.onEvent = mySelectionHandler;
runtime.addEventHandler( selectionHandler );


The problem is that observing *isn't* catching, and there's no way to prevent the default event bubble - your alert box appears, but the node goes red even though you've disabled that effect for in-scene mouse clicks. What you have to do is clear the selectedNode object within your handler function (so it goes red but only for an instant):

var mySelectionHandler = function( event ) {
scene.selectedNode = undefined;
if ( event.selected ) host.app.alert("you clicked on " + event.node.name);
}

Thanks again!

One wonders why you cannot just override whatever gets called when you use "scene.selectedNode = xx" and then no matter where the selection event occurs, it would be invoked. Perhaps that will be for a future API release.

Hello,

the examples above work quite well. Unfortunately they only work in collaboration with the host.app.allert function. I'm not really a JavaScript-Pro so its sort of difficult for me to sort things out in the given example.

If I set up something for the selected mesh like:

myMesh.renderMode = "illutration";

it works so far that it will change the rendermode for the selected mesh but the selection works like it did before. The selected part turns red and also there is the bounding box.

I also tried to only use the line:

runtime.overrideSelection = true;

but that don't do anything at all.

What I try to achieve is, that the end-user isn't able to select anything in the 3D-Annotation or at least if he can select something he can't see, that there is something selected.
I'm not using a part-list or a BOM so that wouldn't be a problem i need to take care about also.

Maybe its usefull to mention that I use DE to author my 3D-Files. I added the examples to the a3D.js-File that comes with the PDF-Publishing-PlugIn and like i said, it works as long as i change something in the "// do your selection-based stuff here" section.

Any help with that would be really appreciated. Thx in advance.