[PD] How do I squeeze more performance out of Gem?

John Harrison johnharrisonwsu at gmail.com
Wed Mar 9 19:08:23 CET 2011

Using Cyrille's test patch for speed which he sent into the list a week or
so ago, I tried creating multiple spheres, gemlists, and models. The sphere
is getting the best performance results, unfortunately. Attached is my test
patch. I just connected [repeat] to either [sphere] [GEMglCallList] or
[model] in the patch. The sphere model I used has probably got way too many
points (just found it on the 'net) but my hope was that as the vertices were
static it wouldn't matter.


maybe one with less vertices will help. I can try...


On Wed, Mar 9, 2011 at 9:48 AM, chris clepper <cgclepper at gmail.com> wrote:

> A model is the way to go since the vertex data is static.  Ideally for
> situations like this there would be one object that loads a single model and
> several clients that just call the display list.  Although there is a lot of
> memory on GPUs now so 200 models of a sphere won't take up that much.
> On Wed, Mar 9, 2011 at 10:32 AM, John Harrison <johnharrisonwsu at gmail.com>wrote:
>>>> On Wed, Mar 9, 2011 at 1:59 AM, cyrille henry <ch at chnry.net <mailto:
>>>> ch at chnry.net>> wrote:
>>>>    hello,
>>>>    - try using a display list to render a sphere, so that every point
>>>> don't have to be send for every sphere.
>>>>    see exemple 09.openGL/02.displaylist
>>>>    you can also use a model with a sphere.obj to have the same result.
>>>> if the spheres are all moving at once, would a display list still help?
>>>> Seems like recompilation would have to happen for every sphere for every
>>>> frame? I haven't tried the model yet...
>>>>  yes, the display list will help to render 1 single sphere.
>>> you have to call it 200 times.
>>> Ok I'm seeing a huge performance difference between using 200 of [sphere
>> <size-doesn't-matter> 20] and [sphere <size-doesn't-matter> 30]. Huge. So if
>> I want to keep the sphere with 30 points, I'm thinking gemlist or model are
>> my answer. I'll try both and report back, unless you have a strong
>> recommendation for one or the other to save me time.
>> This list is awesome. Where else could I find help like this? :-)
>> -John
>> _______________________________________________
>> Pd-list at iem.at mailing list
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