> Date: Thu, 20 Mar 2003 14:42:17 +0000 > From: Jeremy Booth <[EMAIL PROTECTED]> > > Been reading up on high res coords after marks post, I'm after some > confirmation. A high res coord defines a point in very high res, you place a > local using a high res coord, and a local lives in the virtual universe. I'm > assuming this means, that any overlapping or very close locals can see all be > 'seen' when rendering the scene, but things like picking/lighting across > locals can't be done as they don't share a BG ?
Java 3D doesn't perform any culling between Locales. If Locales are close enough that the differences between the hi-res coordinates of their objects can be represented accurately by the rendering hardware, then they can be "seen" by each other. Depending upon the precision of the rendering hardware, you may need to perform some culling between Locales to prevent inaccurate renderings. I took another look at the OpenGL 1.4 Specification. In Section 2.1.1 "Floating-Point Computation" it specifies that OpenGL implementations need only be accurate to about 1 part in 100,000. So it's probable that the more inexpensive gaming cards are not going to give you much more than that. If you can keep the ratio of your smallest to largest dimensions less than 1:10e5 then you should be able to get away with using a single Locale across any card that supports OpenGL. If not, then you'll need to use multiple hi-res Locales and you'll only get accurate rendering across Locales if the objects being rendered are less than 100,000 quanta apart. Lighting is supposed to work across multiple Locales, subject to above constraints. A Light node applies to all nodes in the virtual universe subject to its influencing bounds, hierarchical scope, and the lightingEnable flag of individual Material node components. Picking is locale to a specific Locale or BranchGroup, so you'll need to perform multiple picks for multiple Locales. -- Mark Hood =========================================================================== 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".
