Re: glColor

On 2007-11-26, Wolfgang Draxinger <wdraxinger@xxxxxxxxxxxxxxxx> wrote:

John Tsiombikas wrote:

There's nothing wrong with the fixed function pipeline. In fact
I avoid using shaders when there's no need to do so, or I try
make their use conditional.

On SM >=3 capable hardware you can bet, that also the fixed
function pipeline is done with shaders. Only that the OpenGL
driver provides default ones and loads them, if shaders have
been "diabled".

I think you missed my point. The reason I don't use shaders unless I
really have to has nothing to do with expected performance with and
without shaders. It has to do with compatibility, and ease of use.

That's why I mentioned the fact that 2 out of 3 computers I use
regularly *can't run shaders*.

It's easy to get carried away with assumptions of cutting-edge 3D
hardware if you're into the games industry, where the target audience
(gamers) continuously buy new graphics cards. But that doesn't
necessarily hold in other areas.

And as far as ease of use goes, it's true that some things are easier to
do with shaders, especially in one-off specialized programs. However as
jbwest pointed out elsewhere in this thread, handling many different
rendering paths at once becomes rather complicated. I won't go into this
now as he explains the problem very well.

And OpenGL 3 will abandon the fixed function pipeline completely
and do everything with shaders.

Yes, so I keep hearing. If that's the case, I have my doubts about the
rate of adoption of OpenGL 3. But it's a bit too early for such a
discussion yet.

Don't get me wrong, I love shaders, and the power they give me to do
many wonderful things like deferred shading, parallax mapping,
and multitudes of illumination models at will. However, I just can't see
the reason to abandon the simplicity of the fixed function pipeline for
most cases where these things aren't necessary.

--
John Tsiombikas (Nuclear / Mindlapse)
http://nuclear.sdf-eu.org/
.

Relevant Pages

  • Re: glColor
    ... On SM>=3 capable hardware you can bet, ... function pipeline is done with shaders. ... use or it will raise the OpenGL learning curve a *lot*. ...
    (comp.graphics.api.opengl)
  • Re: Determining which skinning Method to use
    ... The main reason is that fixed function skinning is limited to 4 ... I have no idea why that is, although the reason I suggested shaders ...
    (microsoft.public.win32.programmer.directx.graphics)
  • Re: DXSDK Docs Optimization Technique
    ... The reason it's useful to pre-multiply for shaders is if you just want ... to multiply by several transforms one after the other (with no other ... >>shader doesn't need them separate. ...
    (microsoft.public.win32.programmer.directx.graphics)