Retrieving actual vertex coordinates of live and transformed shape3d

Engines, Libraries and Tools Java 3D
#1

4 vertice shape3d object (2D rectangle) is created around the origin (0,0,0). Through the use of the program, the rectangle is translated and rotated. I need to be able to retrieve the current coordinates of a specified vertex at any time.

I can retrieve the vertex coordinates and the vector of the movement of the object. I can get a Matrix3d object of the rotation of the object, but I do not know how to apply that to get the current coordinate of the vertex.

Here’s what I’ve got so far…


        Point3f p = new Point3f();
        Shape3D s = * retrieved shape *;
        GeometryArray geom = (GeometryArray) s.getGeometry();
        geom.getCoordinate( corner, p );
        
        Transform3D tmp= new Transform3D();
        s.getLocalToVworld(tmp);
        Vector3d trans = new Vector3d();
        Matrix3d rot = new Matrix3d();
        tmp.get(rot, trans);

trans gives me the vector
(-9.0, -1.8125, -14.0)

rot gives me the matrix
-1.0, 0.0, 1.2246467991473532E-16
0.0, 1.0, 0.0
-1.2246467991473532E-16, 0.0, -1.0

Any help will be much appreciated.

#2

if foo is a Shape3D then

foo.getLocalToVWorld()

will return the total current transformation of the SHape32D in world space.

Retieve your vertex from the shape3d’s geometry, transform it with the transform above, and voilla./