RE: [Algorithms] OpenGL LockArrayEXT ... workaround

[Ignacio C. <i6...@ho...>]

Maik Gerth wrote:
> yup ... thats what i mean ...
> but what do i do if my vertex array is tooo big?
>
> an unaccelerated vertex array is way too slow in compare to the accelerated
> version ...
> I get a performance increase of 30 % using LockArrayEXT ...
> without it ... vertex arrays are not even a real improvement to im-opengl
>
> so i guess there is no other way than splitting the vertex array : (?

Splitting the your vertex arrays just before locking them can be very tedious, since you have test
triangle of the element array, so that no triangle get splitted and no index references a vertex of
the wrong buffer. It's much easier to do that in an early stage of the rendering pipeline, for
example, for curves it's easy to split them at tesselation time so that the number of vertexes keeps
lower than your desired number. You could also build your characters and objects using different
meshes, instead of a single one.

For gf cards the best workaround for that problem is using vertex array ranges to DMA-copy your data
and overcome CVAs restrictions.

however i think this discussions belongs to the OpenGL gamedev list instead to this one.


Ignacio Castano
ca...@cr...