I'm pretty stoked about all the new shaders, but I'm concerned about investing lots of effort into effects that very few people will be able to see.

1. Can any shaders, like bump-mapping, be done without DirectX 9? Which ones?

2. If I have DirectX 9 installed on my computer, but I don't have a video card to take advantage of it, then DirectX 9 effects like Normal Mapping simply won't play at all, right? And if there isn't a fallback programmed into the shader, the entire object will be messed up, right?

3. Are there other effects that require specific hardware capabilities or fallback options? (For instance, if somebody has a lousy 3D card, and they play a game with a burning torch made of particles--will they just see nothing, or will their FPS just drop?)

DX9 is NOT supported yet in A6...only 8.1 (or less? not sure abiut that part)
even the latest normal mapping shader runs on a geforce4

Excellent. Thank you. That gives me two follow-up questions:

1. So how will the Normal Mapping shaders and such get better or easier when 9 is implemented? (I assume there's got to be something good about DX9)

2. If DX9 features are not the video card's limitation for the current batch of shaders, what is? For instance, your Normal Mapping shader runs beautifully on my Quadro4 900 XGL, but objects go transparent on my ATI mobility M4 (kind of a cool ice-cube effect actually ). What is it specifically that older video cards need to run the current shaders?

DX9 really won't make the shaders all that much easier.

HLSL is more easily read by the human eye, but it is really no more difficult to write a DX8 shader than it is to write a DX9 shader.

As far as looking better, the 2.0 series of shaders do not really add anything as far as new techniques, but they do encapsulate a number of often used techniques so that you don't have to constantly rewrite the same lines of code. With a few exceptions you can recreate any shader that is running with DX9 in DX8.

Pixel and Vertex shaders of the 3.0 series though do add a whole lot of additional features. A lot of these are impossible without using 3.0 techniques...granted get a hold of a card that will run them is damned hard...so it is a moot point.


In order for shaders to work, the video card has to have a programmable graphics pipeline. A lot of older cards do not. Or if they do they have access to only limited functions. You can find out what cards support what shader techniques with a bit of research (there is a database that contains almost all of the video cards and what they support somewhere...I don't have a link handy though).

For the most part though it is hit and miss on shader support for old video cards (not even all that old - they were not entirely common until the 8500 series of Radeon and nVidia...well, they tend to crash a lot ). Be sure to include a good fall back technique.