Hi Julien,

A general discussion of vertex array object would be best done on
osg-users forum/mailing list as lots of other would likely be
interested in the discussion and have their own perspective.  So
rather than reply here on an osg-submissions thread I'll answer
questions over on an osg-users thread.  Feel free to kick one off.  My
implementation is getting pretty close to be ready to call for wider
testing.

Robert.

On 14 August 2016 at 16:28, Julien Valentin <[email protected]> wrote:
> Hello,
> I've just look at the VAO branch, I have not tested -not enough HD space:/ so 
> I can't give a full feedback
> I can only compare with my own impl with this reduced perspective, I don't 
> understand all so don't be regardant if i misunderstood the code:
> -I like the idea of deporting vao in state..It seams a good place for them 
> for state sorting.
> -But I haven't spot the way you intend to share VAO among Geometries:
> *you don't seam to use a singleton for bo affectation to geoms (so you're 
> assuming user is in charge of sharing bo correctly among geoms?)
> *it seams you haven't changed primset so I'm asking myself how could you 
> manage basevertex when  geoms arrays share same bos
>
> In my impl, I use a singleton to manage bo sets involved in vaos, it 
> concatenate bufferdata in these bo and so bos and vao are shared among 
> geometries
> Further I also use drawElementBaseVertex to draw them in order to take into 
> account offset induced by concatenation of bds in bo
> I did a test in debug build (on a GTX640) with a triangle indexed city and 
> default useVBO
> it originally frames at                             40FPS
> +adding bo sharing among geometries :  55FPS
> +adding useVAO                                    70FPS(The Draw charge drops 
> from 12 to 6 even if i unbind vao after each geom draw)
>
> https://raw.githubusercontent.com/mp3butcher/OpenSceneGraph
>
> Again, these are just observations of gl features that accelerate drawing and 
> that i would be glad to find in osg and not guidelines on what/how to achieve 
> their impl.
>
> I'll give you further feedback when i'll have actually test the branch
>
>
> robertosfield wrote:
>> On 8 July 2016 at 13:49, Mathieu MARACHE <> wrote:
>>
>> > Great news ;-)
>> >
>>
>> Was hoping to finish it today, but have a birthday family walk and
>> dinner planned for the rest of today so heading off line.
>>
>> I have a prototype of VAO functionality kinda working.  Performance is
>> on big city models better than without VAO but still not as good as
>> with display lists...
>>
>> I'm currently refactoring the internals of how vertex data is passed
>> to try and avoid some of the CPU overhead.  I expected there is couple
>> more days work getting it all working smoothly.
>>
>> Robert.
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