31 replies to this topic

[baldurk]

am I right in thinking that only the ATI Radeon 9700 supports arb_vp in hardware? or is that arb_pf. I seem to remember that the GF4 can't do one of them, and I felt cheated because I only bought it so that I could do them :/

[davepermen]

ARB_vertex_program is hw on gf3+ (without all mx craps)
ARB_fragment_program is r300+ only (radeon9500 and bether)

[CyraX]

If you read the .plan of Carmac you will realise the number of features (he talks mostly of the performance as a function of color depth) what we all fail to realise is that OGL and DirectX have been REALLY made for different purposes.
OpenGL is a "tru" graphix library allowing the complete Rendering pipeline to be exposed. DirectX would not expose the rendering pipeline as such but the hardware apis enable it.
Now that is exactly the reason most of hte colleges/courses teach OpenGL - it teaches Graphix and not hardware specific routines.
Perhaps the ONE way OGL can beat the DirectX API is by having a different pipeline mechanism for games and for apps.
That way OGL might just be able to reach DirectX level.
Oh btw DirectX 9 might stay for a long time (gdconf) because M$ is not going to release a new DirectX library anytime soon.
Might be that this the ample time and the right time for OGL ARB to just revamp the whole pipeline and redo the processes.

[sumedhs]

Well the debate of OGL Vs DirectX continues...

One of the major advantages of an OGL code is that its portablility & genericity to any language. I can have one function defined in VC for panning in 3D & the same will work good in Python! We just need to handle the data types but the OGL calls more or less remain same.
Python has an implemented PyOpenGL library that implenets all the openGl calls. Its much easy to handle things there.
Nextly Gaming is not the only industry where CG is Used. Are we overlooking the Huge CAD/CAM industry?
I used a DX in some earler projects in my CAD firm but there was one where we needed to implent Model Deformation through Graphics. The challange was that the code needed to be workable on IRIX. PyOpenGL was the solution.

I think we all need to get out of the hole that Microsoft is digging by forcing us to follow their standards. Just because lot of people use MS standards does not make it better.

Besides that I personally find OGL is very easy to implement. One thing where OpenGL *USED* to fall back was device interface; But OpenGL was intended to be a purely a graphics API.

Anyways now with the advent of OpenML & OpenAL it has almost overcome its limitations wrt DX as well!
OGL LIVES!

[baldurk]

hmm, I'm not sure that cg would be used in CAD/CAM. There are more appropriate solutions for the CAD/CAM industry, which aren't appropriate for games.

[CyraX]

CG would be used in Gamez and presentations, media - LOTR stuff.
In CAD/CAM you dont need stunning graphix, what you need is realism interms of physics and physical quantitites.

[Merlin]

What is cg anyway? An OpenGL modelling tool?

[baldurk]

Cg is a high-level shading language developed by nvidia. It can compile into Dx9 code, and OGL code, either NV_* extensions or the ARB_vp and ARB_fp extensions. It's completely compatible with the HLSL

[donBerto]

addendum:

HLSL: high level shading language.

:yes:

[baldurk]

to further clarify (;)), HLSL is indeed the high level shading language. It was written, designed and implemented solely by Microsoft for DirectX 9.0. This is different to GLSL (GL shading language) which is being designed by the ARB.

[davepermen]

and its not glsl but glslang, short for opengl shading language

[CyraX]

CG has the advantage wrt the programming paradigm.
Works either on OGL/DX whichever is available (you can also select).
Works on HW that supports DX9.0 or OGL 1.4 (onwards). So will work on ATI tooo.
I wud give it thumbs up... pretty neat API.
Tho has its own set of problems - not really evolved.