Hi, I' ve already tried this way, but the method of the class Intersect, doesn't seem to work very well. When I call the method, for instance, rayAndQuad, it needs an array of Point3d (the coordinate of the vertex of the QuadArray). The method I used to retrive information about the vertex is QuadArray.getCoordinates(int,Point3f/Point3d). When I try, java rise a Null Pointer Exception. Why? Is a bug or is my inexperience with java? Regards. ===================================================================== To subscribe/unsubscribe, send mail to [EMAIL PROTECTED] Java 3D Home Page: http://java.sun.com/products/java-media/3D/