Im trying to determine what depth of texture units and usage of shaders to do in my project.
Guess the PC requirement will be that of WoW, so any PC produced within the last 3 years will be fine ( pentium 4 + ), its too painful to not take advantage of the shading features.
Would it be safe to say that as long as the graphic card is less than three yeras old it will be OK to support shaders and 8 texture units. Nvdia ATI etc inclusive, or should requirements be based on listing supported cards ( nasty )
Well I can't advise on what you should do as I know nothing about Graphic Card support, but I know what I would do.
I'd try to use as little 'advanced' features as possible, until I came to something impossible to do with shaders (that I really needed) or something that would take so long that it wasn't worth trying to support old cards.
You can check for things like texture units and shader support as at least you can give the user a nice message instead of crashing out horribly.
I have and intel® GMA-Intel® Graphics Media Accelerator Driver for Mobile Report
ie. crap, but it is still less than a year old.
None of the shader tests work on my computer, they run, but they don't look like they should. I tested out another guys laptop and his didn't show it right either. Turned out he had the exact same graphics card.
I'll be a bit more specific when i say shader tests(At least thats what i think they are):
TestBloom
TestMotionBlur
TestSketch
TestProjectedWater
TestQuadWater
TestSimpleQuadWater
and oddly enough
TestCameraMan
even though i don't think it uses shaders.
This is a nightmare IMHO
just wonder if anyone has got a simple GPUSupport utility knocked up to to check these things.
camera man uses FBO. You might confirm with trying TestRenderToTexture.
I see a Cube of dirt not sure if i'm supposed to see more.
If you want I can post a screen shot of all the tests that don't seem to work.
Can't right now, but later today if you want.
like in any game you can/should just test for how many textureunits is available and for shadersupport and either let the user know or create fallbacks(last one being the best option offcourse)…
The worst thing is that current trend is to sell a lot of PCs based on matherboard integrated GPU chips, like the well known Intel GPU chips.
Considering that most of the game players do not want to spent too much (at least here in Italy), are basic users, that generally do not know anything about a computer, and therefore they buy what the computer shop vendor advise them to buy 
, we are going to have a wide range of the potential game players that have poor performances GPU chips or bad OpenGL support. Moreover this tendency is strengthened by the diffusion of portable computers, that in the low cost configurations do not have separated graphic cards and come with integrated GPUs.
And more: generally these GPUs do not have large capacity dedicated VRAM and share part of the system RAM.
Running around jME running more tests(theres a lot :)) Ran TestEnvMap, it worked. I thought that was kind of odd since the water tests don't work(I thought they might use the same technique) Then I ran TestMipMaps: WARNING: FBO not supported. That answers that. I haven't seen that output on any of the tests before.
I have a fairly new computer (2 years old), with Pentium 4. You would say I could run a normal 3d game on it. Unfortunately enough, I've got an SiS 651 on it (doesn't support openGL at all). So I cannot play most games. (I'm planning to buy a GeForce, since I've seen XGL/Beryl, I cannot think of something else). On the other hand, my laptop is about 3 years old, with a Pentium 4 ME. It has an ATI card, and framerates for jME are a lot higher, and with some effort I can run Compiz. So you see, you cannot just say "All computers that are made 3 years ago or later", since there are still people with bad graphics cards.
SeySayux said:
... since there are still people with bad graphics cards.
I quote you.