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

[John Harrison]

thanks for these suggestions. Here's how it's going so far:

On Wed, Mar 9, 2011 at 1:59 AM, cyrille henry <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...

>
> - gemhead are slow. i usually have better result using 1 gemhead and 200
> separator, or 200 gemlist, than using 200 gemhead.
>

It actually performed marginally slower with 1 gemhead and 200 sep and also
slower with 200 gemlist

>
> - try to put somewhere :
> [gemhead 1]
> [GEMglLightModeli GL_LIGHT_MODEL_TWO_SIDE GL_FALSE]
>
> it help a lot on my computer (GT 425M), but i don't know on other computer.
> could you try and tell me the performance improvement?
> (you may have to reverse some light to have close lighting result).
>