Doug Twilleager wrote: > > This thread, and the performance thread, have raised a number > of issues. I'd like to give our answers/perspective on these > issues. Beautiful. Thanks. From my POV in the original reply, I was trying to present as objective as possible assesment of the good and bad points of J3D with some relative contexts to other APIs as it stands today. > Now let me try to address the variety of issues being raised. > > Open Source: > Java 3D is an extension to the Java platform and Sun is in the > process of defining a community source model for standard extensions. Yes, I know as I've been struggling over with the JSDT stuff too. From my POV, it was a statement about how I think the quality of J3D could be improved in the future. It's not taken as a religious "release the source now or I'm not going to use it" perspective. From the user community the updates/bug fixes have taken far too long to make it to us and I feel this is a better way of getting it done. As I said before, it's more an upper management problem, not the coders at the coal face that have this decision to make. > Video Texture: > To do true video texture in hardware, the API needs to expose > hardware specific synchronization features. We aren't ready to > go down that pathway yet. But 1.2 does add the ability to have > a texture reference user data directly without making an internal > copy. This should help with this feature. I also imagine that to do it "properly" in the Java Philosophy sense that you really want to integrate it with JMF/JavaSound so that you just plug the two together. This means work from both sides of the fence are needed to make this work nicely. (I'm thinking that if done well, you almost end up with an MPEG 4 renderer without much effort). > Audio Rendering: > Our to do list includes a DirectSound audio device implementation. > This will help a lot of the sound performance cases. Since the audio device > is an interface, anyone could write this and share it. Any takers? :^) When I've talked with the J3D developers before (both privately and at Siggraph/JavaOne) the message I got was that 3D audio rendering is not available at all in the current implementation. That is, all of the spatialisation is done within the J3D runtime and then passed to the AudioDevice as a pure stereo mode. Therefore, even if you had a 3D audio device that was implementing DirectSound/AudioDevice3D it would not use the capabilities at all. This is the first time that I've heard anything to the contrary. Could you expand on this please. > Transparency: > It seems that most folks don't know what we do with transparent > objects. The Java 3D rendering order is as follows: opaque objects, > ordered objects, transparent objects. The problem with this is that it all sounds fine in theory, but in reality it sucks badly. VRML browsers (as one example) do this very nicely and have never had a problem with it. It is, as far as I can tell, impossible to do a mixture of semi-transpareny objects, lines and standard geometry and have the thing rendered correctly even when taking into account all of the pointers that have been posted to the list over time. I've attached an example image to show you what happens. A single texture with alpha works fine. Add another object that doesn't have alpha in the texture and it all goes to wrong. Note that the green lines should go to the edge of the white texture and stop because the end up behind it. The opaque texture is actually in front of the tree so that should not show up either. > Multiple Screens: > This is in Java 3D 1.2 with JDK1.3. > > Stereo: > This was a bug in 1.1.2. It is fixed in 1.2alpha1 and the upcoming 1.1.3. Just wondering - are you/SGI licensee incorporating the SGI OpenGL patch that got posted to the list a few weeks ago? Seems like a pretty serious bug to me in that particular implementation. > Input/Output/Audio device configuration: > We are prototyping a configuration utility that will handle this > very cleanly. Think of it as a very complete SimpleUniverse utility. > This won't be in 1.2, but will make a future release. Cool! A race :) Let's see who gets there first :P -- Justin Couch Author, Java Hacker Snr Software Engineer [EMAIL PROTECTED] ADI Ltd, Systems Group http://www.vlc.com.au/~justin/ Java3D FAQ: http://tintoy.ncsa.uiuc.edu/~srp/java3d/faq.html ------------------------------------------------------------------- "Look through the lens, and the light breaks down into many lights. Turn it or move it, and a new set of arrangements appears... is it a single light or many lights, lights that one must know how to distinguish, recognise and appreciate? Is it one light with many frames or one frame for many lights?" -Subcomandante Marcos -------------------------------------------------------------------
