Ooops! Kelvin tell that bug 4722648 - Non-uniform scale causes lighting errors - is fixed in J3D v1.3.1 beta1
Actually is not fixed. See the attached picture obtained with j3d v1.3.1 beta ogl. The blue areas should all have the same color, since the surfaces are all parallel and the light is directional, but actually you can see 3 different colors. A very small amount of non-uniform scale was applied to every brick to create a small distance between them (a seam). Cheers, Florin -----Urspr�ngliche Nachricht----- Von: Florin Herinean Gesendet: Mittwoch, 19. M�rz 2003 09:07 An: 'Discussion list for Java 3D API' Betreff: AW: [JAVA3D] Problem with Specular Color Yes, that's the bug. So version 1.3.1 have it fixed. Lot's of nice fixes in 1.3.1 ! When will be a fcs release ? I was scaling up, the actual geometries were bigger than the original size which was always normalized, size 1 in all directions. I've fixed my problem by using the workaround specified in the first paragraph: "Scaling the geometry data explicitly and recomputing the normals without using a non-uniform Transform3D will always work, but is expensive." Actually, in my case the "is expensive" proved not to be true, there was absolutely no difference in loading time, memory usage or rendering time. Also, in the bug report there is a small error: "The bug only presents itself when the scale is changed dynamically. If the Transform3D is initially created with a non-uniform scale, then the lighting is correct until Java 3D notices that the scale has become uniform again." That's not true. In my app I was creating the transform3d directly with a non-uniform scale and never touching it anymore, but the lighting was incorrect. Cheers, Florin -----Urspr�ngliche Nachricht----- Von: Kelvin Chung [mailto:[EMAIL PROTECTED] Gesendet: Dienstag, 18. M�rz 2003 22:14 An: [EMAIL PROTECTED] Betreff: Re: [JAVA3D] AW: [JAVA3D] Problem with Specular Color Monica Sleumer wrote: > I agree that the non-uniform scaling probably has a lot to do with it, > because I noticed that the effect got worse the more I scaled the > geometry. For instance, the cylinders that still looked like cylinders > had no problem, but those that were scaled down into disks a few pixels > thick had serious problems. > Unfortunately, I have to scale everything to the proper size in the > application I'm writing. At least setting the specular color to black > and the shininess to 1 removes the specular color artifact for now. > > Florin, did you scale your shapes up or down? That is, did you make them > appear bigger or smaller than the original geometry size? In this > application the shapes are always being scaled down. The original > cylinder shape is much larger and longer in proportion than any of the > cylinders in this application. I wonder whether scaling a shape down > makes the specular color much brighter while scaling a shape up makes > the colors much darker... > > Anyways, maybe I'll have fewer problems if I start with a VRML shape > file that is closer to the eventual size of the shape that will be > displayed, so that the scaling is less extreme. I'll try that next. > > Monica In case you're using J3D v1.3 release, there is a bug 4722648 - Non-uniform scale causes lighting errors which is fixed in J3D v1.3.1 beta1. - Kelvin ------------ Java 3D Team Sun Microsystems Inc. =========================================================================== 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".
<<attachment: test.jpg>>
