What is your approximate experimental fps improvement using exactly the same content with and without VBOs? I'm testing with 3000 static verts (GL_STATIC_DRAW) and I'm getting exactly the same frame rate with and without VBOs, only the set-up time is longer with VBOs. What are your results with and without? If you're sure there's an improvement, then what might I be doing wrong with my VBOs? (I'm using 2 VBOs, one for the indices and the other for verts, normals and texturecoords) And what's your way of doing it?
On Jun 20, 11:50 am, Robert Green <[email protected]> wrote: > The question "are VBOs faster" is a very subjective one. > > I can answer the question "are VBOs faster for large amounts of static > geometry" and the answer in my experience has been "yes, very much so, > especially on first-gen devices." > > For quads and such? No. In fact, it could actually be slower > depending on the chip and implementation. > > VBOs are designed to reduce bus bandwidth usage for static geometry. > If you're not pushing too much across that bus (as in the case of > quads or very few, very low poly objects), they won't do much. If, on > the other hand, you're actually running static scenes that are moving > 5k polys per draw eg (7.5k verts, 7.5k normals, 15k indices, 7.5k UVs) > = 270Kb, you will most likely see some sort of improvement, especially > on chips like the qualcomms as they have fairly slow transfers. Just > think, 270Kb @30fps = 8.1Mb of memory copying per second you're saving > using VBOs. > > If you're rendering scenes that have REALLY large amounts of geometry > (for mobile), such as 50k or 100k polys, you'll find that you'll be > totally vert-bound on the first gen devices, so there's kind of that > limit there as to how effective VBOs can be. The spots where they > REALLY shine, like really high poly counts, can't ever be used on the > first-gen phones because they are incapable of processing that many > vertices with high efficiency anyway. High end devices running big > scenes like that will really benefit from them because it's a whole > lot of memory transfer savings. Anyone doing things like that will > want to be using configurable LoD to support the first-gens while > keeping things high quality on newer chips. > > I would be interested in a simple test that increases poly count frame > by frame and graphs the FPS up from 0 to 100k polys. Running one pass > textured and the other just colored would be a good way to > discriminate between becoming fill-bound and memory or vert-bound. > Seeing this data on an MSM7200, Cortex/PVR (Droid) and a snapdragon > would be very useful for determining optimization targets. > > On Jun 20, 4:37 am, Navigateur <[email protected]> wrote: > > > > > No I'm not even using draw_texture. I'm comparing using VBOs to just > > ordinary Buffers for the vertices (and no draw_texture). My test is > > not near the max frame rate for my device. > > > On Jun 20, 12:21 am, Miguel Morales <[email protected]> wrote: > > > > Well, if you look at the talk google gave the developer gave a short > > > note about > > > it:http://code.google.com/intl/es-ES/events/io/2010/sessions/writing-rea... > > > If memory serves me correct, you won't gain much of a speed gain from > > > using VBOs as opposed to say draw_texture. > > > This is because the FPS is capped at 30FPS for some devices, however I > > > can't recall the details. > > > > Miguel. > > > > On Sat, Jun 19, 2010 at 3:01 PM, Navigateur <[email protected]> > > > wrote: > > > > I've been trying VBOs (3D) and I've seen no improvement at all on my > > > > Motorola Dext over not using VBOs. > > > > > I've tried all kinds of configurations, interleaved arrays, > > > > bytebuffers instead of floatbuffers, both direct and indirect. > > > > > My question is, has anybody got any measured improvement in frames per > > > > second by using VBOs instead of exactly the same content without VBOs? > > > > > If and only if so, what were your fps results? And can you therefore > > > > show me the "proper" way of doing VBOs instead of not? > > > > Has anybody else got exactly the same fps with and without VBOs? > > > > > -- > > > > You received this message because you are subscribed to the Google > > > > Groups "Android Developers" group. > > > > To post to this group, send email to [email protected] > > > > To unsubscribe from this group, send email to > > > > [email protected] > > > > For more options, visit this group at > > > >http://groups.google.com/group/android-developers?hl=en > > > > --http://diastrofunk.com,http://developingthedream.blogspot.com/,http:/..., > > > ~Isaiah 55:8-9- Hide quoted text - > > > > - Show quoted text -- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
