[away3d] how to resolve a Segment from a DrawSegment

[scott]

Hello,

Hopefully someone can give some insight on this - I searched the forum
and it doesn't look like this one's been answered before.  I'm trying
to figure out how to get a Segment from a DrawSegment.  For instance,
if the user clicks on a DrawSegment on the screen, I'd like to figure
out the Segment that that DrawSegment corresponds to in the clicked
Mesh/Object3D.  For a DrawTriangle you can retrieve the corresponding
face object by referencing (myMouseEvent.drawpri as
DrawTriangle).faceVO.face, but I don't see any similar way to do this
for a DrawSegment.

So far I tried getting the two ScreenVertex endpoints of the
DrawSegment and using deperspective() to convert those ScreenVertices
to Vertices, creating a new Segment with the Vertices, then comparing
that Segment to Segments contained in the clicked Mesh in order to
find the corresponding one.

Here's the code at the core of it -

function GetSegmentFromDrawSegment(drawSegment:DrawSegment):Segment
{
        var screenV0:ScreenVertex = drawSegment.v0;
        var screenV1:ScreenVertex = drawSegment.v1;
        var v0:Vertex;
        var v1:Vertex;
        var segment:Segment;

        v0 = screenV0.deperspective(drawSegment.view.camera.focus); //get
vertex from screen vertex
        v1 = screenV1.deperspective(drawSegment.view.camera.focus);

        segment = new Segment(v0, v1);

        return segment;
}

However, when I run it, conversion of the DrawSegment ScreenVertices
to Vertices gives position (x,y,z) values that are way off of the
actual corresponding Segment in the model, so I must be doing
something wrong and/or misunderstanding how things work at the heart
of the engine.  If anyone can offer advice I'd appreciate it.

Thanks,

Scott