In 1.1.* there was very little difference between operations
when capability bits were set. Things have changed quite a
bit since then. For instance, whether we use vertex arrays or
display lists in OGL, or vertex buffers in D3D is influenced
by capability bits. Thes types of tradeoffs will only become
more pronounced as we move forward. Especially when we factor
in compiling scene graphs.
Doug Twilleager
Sun Microsystems
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>Subject: Re: [JAVA3D] Range ordering of transparent objects
>To: [EMAIL PROTECTED]
>
>"J. Lee Dixon" wrote:
>>
>> Now I think my problem is the slowness of moving BranchGroup nodes
>> around in the OrderedGroup. I thought I had heard that detaching a
>> BranchGroup and re-attaching was very expensive. I tried searching the
>> archives but the listserv search engine is a bit slow for me right now.
>
>A couple of years ago we did some profiling of branchgroup performance.
>We had scenes where the geometry was being updated/changed on a very
>rapid rate. The profiling was to look at the performance difference
>between removing the BG, adding/removing the geometry and putting it
>back in with no capability bits set, versus directly adding/removing new
>geometry with all of the capability bits turned on.
>
>Now my memory is a little fuzzy, and this would have been with J3D 1.1,
>but there wasn't that much performance difference between the two
>approaches. Up to around 500 children in a single BG they were neck and
>neck. Beyond that, the capability bits made it a little faster. Once you
>got to around 2,500 children then the BG went exponential with the
>detach/add and the add became a steeper linear (i think, but not off the
>charts like BGs did). ie The conclusion from this was that for most
>normal scenes, capability bits weren't worth the effort needed to put
>them into the API.
>
>
>--
>Justin Couch http://www.vlc.com.au/~justin/
>Freelance Java Consultant http://www.yumetech.com/
>Author, Java 3D FAQ Maintainer http://www.j3d.org/
>-------------------------------------------------------------------
>"Humanism is dead. Animals think, feel; so do machines now.
>Neither man nor woman is the measure of all things. Every organism
>processes data according to its domain, its environment; you, with
>all your brains, would be useless in a mouse's universe..."
> - Greg Bear, Slant
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