Lan: As far as the actual surface geometry is concerned, I believe Quadrilateral and Triangle surfaces are linear interpolation between the corner point locations. I think I remember reading that the rendering of a non-planar (not all 4 corners lie on a single plane) Quadrilateral may produce undefined results, probably dependant on how things are handled behind the scenes in OpenGL or D3D. I typically avoid Quadrilaterals, and explicitly deconstruct the Quad into two appropriate triangles. If you specify surface normal information for a Quadrilateral or Triangle, I think this is used only by the Lighting algorithm to set the local brightness and color on a quadrilateral or triangle. I think your specified normals can be anything you want, and will just change the way the lighting model shades the linear interpolated surface, not the rendered surface geometry. Hope this is helpful,
Happy Holidays Matt Pierce -----Original Message----- From: Lan Wu-Cavener [mailto:[EMAIL PROTECTED] Sent: Tuesday, December 23, 2003 11:25 AM To: [EMAIL PROTECTED] Subject: [JAVA3D] how does Java3D determine the grid surface -resent I guess that everyone is busy for the holiday. But I am going to re-send this question again. To make it clearer, I would like to know how I can find out the elevation of the center of the grids. Does Java3D interpolates the Y using some formula? Thank you for your time! and Merry Christmas! Happy New Year! Lan At 04:34 PM 12/22/2003 -0500, you wrote: >Hi, > >If all four vertices of a grid have different normals, ie. the four >vertices are not in one plane, how does java determine the shape of the >grid surface? I use a flat grid to render shrubs on ground, and then >need to orient this pre-set grid to the actual grid surface. I am >having problem to find the orientation that Java3D generated. I wonder >if anyone could help me out. > >Thank you very much in advance! >Lan > > >Lan Wu-Cavener >Dept. of Landscape Architecture ======================================================================== === 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". =========================================================================== 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".
