Shaders using halfs are usually faster even on GeForce 7 class hw because of dedicated normalization unit and increased latency hiding capabilities.
Don’t know its origin but a half float is in most conditions alot more than enough, and half memory cost
Nonsense.
Half-floats are a phantom. An illusion. For half of the hardware out there (more than that, now that nVidia has largely abandoned them), half-floats don’t even exist.
There’s no memory savings with half-floats because ATi doesn’t support them. They never did. On no ATi hardware will you see a benefit when you use them. And since it isn’t something that is cross-platform, it isn’t something you can rely on.
Now, maybe it’s something you want to test for and swap in different shaders. But it certainly isn’t something that ATi or anyone else should be forced to support in any way just because nVidia decided to save some transistors in their NV3x/4x hardware.
You are greatly underestimating features of the D3DX. There is more in it beyond simple helpers. I would suggest that you read its documentation.
Even the HLSL compiler is part of the D3DX and not of the core runtime. Or the D3DX contains mathematics operations optimized by individual CPU vendors (as far as I know). Also the effect framework which appears to be used by some professional developers is part of the D3DX.
Some features of D3DX are clearly meant for use in build pipeline (e.g. the unwrapper of uv coordinates, functions for calculating coefficients for precomputed radiance transfer). Yes, you can write your own version however why do that if someone else already created usable one.
Actually, you don’t need an “SDK” at all (actually I never understood what this SDK thing is about?
DX SDK is about nice package in which you get documentation, headers, latest version of D3DX library and examples.
If they really choose to abandon halfs, I wish they would at least add a color-renderable GL_RG32F_ARB texture format to get 64 bits per pixel (mainly to save bandwidth in PBO operations).
Right now, the only non-RECT color-renderable tex format with 64bpp is GL_RGBA16F_ARB. It’s supported natively up till NV44 that I know of, don’t know if it’s supported natively on more recent hardware though.
Nvidia’s CUDA language still has support for halfs through the CUDA driver API and CUDA is only supported on GF8 and up so I guess it’s still supported natively on GF8 hardware…
Please correct me if I’m wrong 
cross-platform what is that exactly… OpenGL isnt even supported directly under most of the worlds computers, i.e sure XP did support OpenGL 1.1, the word cross platform is an illusion…
Halfs aint the hardware has it, or you havent used 16 bit floating point blend? Never tried a fast normalization using half4 ?
You can get all the OpenGL functionality you need just by downloading the appropriate graphics card driver.
About cross-platform… I just can’t use Direct3D in Linux 
Korval is talking about the half type within the shader (which still has advantages on GF7 and older hw, I do not know how it is with the G80), not about the 16F format of textures/render buffers.
Ah, I see. Guess I was thrown off by the ‘half memory cost’-quote in his post
And, i was talking about the 16F textures/render buffers ><
“Not needed at all” was the phrase I replied to; this implies there is no requirement AT ALL for it, however the fact that it could be helpful (and indeed, one the reasons I’d recommend learning D3D over OGL right now is that having D3DX and DXUT takes away some of the pain) proves there is a need for beginners.
It ok for people who have been using 3D APIs for a while to say ‘oh, you can code this in a day or two’ or ‘people in industry won’t use it’ and I’m sure it’s true however everyone has to start some where, and at the point of learning the API to get an intrest not everyone can write the code in a day or two or wants to use some great abstraction over the API; they want to use the API and it’s helpful to have support code there which is ‘offical’ and known to work properly.
Yes, a cleaner API will help and that should be a priority ofcourse but you can’t sit there and write something off as ‘not needed’ because professionals wont use it… there is more to the OpenGL world than professionals and people who have been using it for years and, like it or not, these people sometimes need something to help them in.
So, no, no problems with the english language here thanks.
What driver ATI hardly supports linux, you cant be serious!
And extensions are always exposed first through the windows driver.
And Mac OS, oh do not get me started 
ATI hardly supports Windows GL, so what’s your point?
Heh, right Ask someone with experience on Windows and ATi…
jumps
That would be me and i think you are exaggerating immensely. I have had the same amount of issues with ATI as with nVidia and usually one could argue that those issues are present because of the complicated specification of OpenGL 2.1.
Let me guess, you are working all day with nVidia-hardware and at some point you run it on an ATI-card and something doesn’t work. Therefore you think ATI is bad.
Well, with me it’s the other way round. I work with ATI-hardware all the time and at some point run it on nVidia. And often something doesn’t work (although it should). Only because that’s my subjective observation it doesn’t say anything about the quality of ATI’s or nVidia’s drivers. It just says, that when you work mostly with one vendor’s hardware, you will only really notice the issues that you have with the other vendor’s hardware.
It is certainly true that ATI was quite bad in the past, but they have improved very much.
Jan.
Let me debunk that for you, I’ve used an ATi card for one full plus a half year. Most of that time was terrible. Not only with programming, but especially in using it with 3d programs.
Before, I used nVidia, before that, I used ATi, which was a horrible time as well. Why I went with ATi again after the nVidia? Well, wanted to have a new system quickly and only ATi was left as a choice… worst mistake I ever made.
Well, with me it’s the other way round. I work with ATI-hardware all the time and at some point run it on nVidia. And often something doesn’t work (although it should). Only because that’s my subjective observation it doesn’t say anything about the quality of ATI’s or nVidia’s drivers. It just says, that when you work mostly with one vendor’s hardware, you will only really notice the issues that you have with the other vendor’s hardware.
Unfortunately, ATi has just really been very very bad in the past, there’s no way around that and I’ve had the full experience.
It is certainly true that ATI was quite bad in the past, but they have improved very much.
Well, I’ll be honest, you’re right. The latest drivers were definitely a lot better and made the whole thing a lot more enjoyable. If they continue like that, I might think about buying an ATi some day again. But for now, I know what to expect from nVidia. And even though nVidia isn’t always great either, they have always given me the best combination of good hardware and good software, and there was always a way to make things run mostly well and to keep things stable (using older drivers, for example). I can’t say the same for ATi.
We’ll see what the future brings! I hope the GL3-spec will be a part of that future, to get back on the topic again
My point is that the cross platform argument for OpenGL does not even hold for two of the largest vendors of graphics hardware, and on different OS it becomes even worse.
OpenGL has too longer slumbered and the marked is forever lost. I suspect that OpenGL 3.0 will not bring OpenGL into a position where it will be able to even slightly compete with DirectX, and this will mark the end of an era which started with SGI and now every thing is crumbling.
Well, as mentioned before, Direct3D (not DirectX, that’s more than OpenGL is meant to be used for) is mostly used for games.
When you look at other apps you’ll see that OpenGL is still king. 3ds Max, Maya, Cinema4D, Modo, Lightwave, Houdini, Blender, Silo, Mudbox, Softimage|XSI, Rhino, Bryce, and that’s only the list of “bigger” names. The list goes on and on. Direct3D doesn’t have any position in that market.
Hm. Pro/Engineer, MicroStation, AutoCAD, Inventor? (Maybe these names are not big enough?)
CatDog
Not my kind of show, but you got the point
Funny thing is that the few of the products you mention which are actually being used by commercial game companies actually have waste support for DirectX, see for example Microsoft FX effect interface. 3DS Max actually uses DirectX as its base renderer.
I am not sure how serious products such as blender and softimage is in the content creation industry? Perhaps you could elaboreate on which game studios uses blender or softimage?
Also think of it, go back 5 years… OpenGL was the defacto standard! Today that position has been taken by Microsoft DirectX. With DirectX 10 Microsoft actually had the standard ready (and with reference device implementation) prior to the release of DirectX 10 hardware. The problem is that Microsoft has managed to direct the evolution of graphics hardware in collaboration with both NVIDIA and ATI. Sure there is Kronos and NVIDIA and ATI are still member of the ARB board; but frankly does it seem like they are devoted to a rescue plan of OpenGL?
There might be a marked for OpenGL ES on mobile devices, but in the long run I dont see a place for OpenGL simply because it evolves too slow, and because the IHVs arent focused on OpenGL at all.
The fact the Microsoft actually publicly release a beta SDK with software reference device implementation shows a lot about their openenes to the end-users (programmers).
They even provided some fairly good examples on its usages, and have keept providing good documentation made publicly available.
For OpenGL 3.0 we have nothing … There is virtually no information on OpenGL 3.0; how should companies be able to prepare prehand for an opcomming standard which is largely unknown? Why this secrecy?