Hi, >On Thu, 7 Feb 2002 13:39:49 +0000, A. Murat Tanyer <[EMAIL PROTECTED]> >wrote:
>Dear Java3D members; > >I created a Shape3D object (rectangular prism) by using quad array; so I >know the coordinates of each vertex. Now, I have a plane which cuts this >object. The plane is defined by a location point and a vector which is >perpendicular to the plane. How can I find the intesection points of >this plane with the Shape3D object. > If you are just interested in clipping the rectangular prism - a hexahedron - with the plane, look into the ModelClip option in the Java3D API. If you are interested in computing the coordinates of intersection between the plane and the edges of the prism, you have to compute the signed normal distances of the vertices from the plane. Then along each edge you interpolate to determine where exactly the distance is zero to get the intersection point. This is the marching hexahedron algorithm. The intersection plane is an isosurface of zero normal distance. >Secondly, when using GeometryInfo, what happens if you don't close the >bounding curve (not like 1,2,3,4,1; but like 1,2,3,4)? > >1*********2 >* * >* * >* * >3*********4 > The polygons are assumed to be implicitly closed. Watch out for the CCW order for describing the polygon though. HTH, Raj Vaidya =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
