Compute Shader And Texture Compression
We mentioned this open secret in the conclusion of our article on CUDA. Microsoft wasn’t about to let the GPGPU market get away and now has its own language for using the GPU to crunch other tasks besides drawing pretty pictures. And guess what? The model they chose, like OpenCL, appears to be quite similar to CUDA, confirming the clarity of Nvidia’s vision. The advantage over the Nvidia solution lies in portability—a Compute Shader will work on an Nvidia or ATI GPU and on the future Larrabee, plus feature better integration with Direct3D, even if CUDA does already have a certain amount of support. But we won’t spend any more time on this subject, even if it is a huge one. Instead, we’ll look at all this in more detail in a few months with a story on OpenCL and Compute Shaders.
Improved Texture Compression
First included with DirectX 6 10 years ago, DXTC texture compression quickly spread to GPUs and has been used massively by developers ever since. Admittedly, the technology developed by S3 Graphics was effective, and the hardware cost was modest, which no doubt explains its success. But now needs have changed. DXTC wasn’t designed with compressing HDR image sources or normal maps in mind. So Direct3D’s goal was twofold: enabling compression of HDR images and limiting the “blockiness” of traditional DXTC modes. To do that, Microsoft introduced two new modes: BC6 for HDR images and BC7 for improving the quality of compression for LDR images.
So, is the tesselation stage similar to AF or bi/trilinear filtering?
Tesselation, from what I've seen, takes a simple model intended for say a 4650 and "upgrades" it in memory making it more complicated and details for higher end cards. If I understand this correctly it will drastically reduce development time and costs while increasing visual quality.
Hmm, not sure about "upgrading" in memory. I looks like it just lets you pass in the control points that define your geometry rather than passing in all vertices for the mesh, which you yourself would probably have defined in a similar manner anyway.
Direct3D remains utterly irrelevant to me as a Linux user.
Direct3D remains utterly irrelevant to me as a Linux user.
But it is relevant to a lot of GNU/Linux users as the Wine programmers have to compatiblise what M$ implements in their 3D API... Currently they are making a dogs dinner of DirectX 9.0 support. However Windows games are generally well supported if they have an OpenGL option... Far Cry for example will not render under Wine in DirectX mode but when switched to OpenGL it works very well.
It is sad to hear about the difficulties OpenGL is having therefore.
Bob
Tessellation as far as I'm aware is adding more triangles to a model to give smoother surfaces over curves. It does not add any visual details but does add to the complexity of the model.
It breaks down the existing geometry into smaller triangles. (most 3d models are built out of triangles to begin with)
Very good aricle, thanks! I'm an OpenGL developer as well, and I wish it the best. I think that now, OpenGL needs money and commercial support - unfortunately these are the rights of current world. It would be a shame to have only one modern 3D API...
"the professional market, where OpenGL is the standard"
what market are you talking about? Please detail. Your readers are mostly common computer users, not specialsts knowing in-depth details about the computer graphics market.
"Since the ARB—the group in charge of ratifying the API’s development—included many different, competing companies.."
What are the most important members of this ARB? Whose words have big weight in that group? The readers might be curious - who are the people generating the conflicts that slow down the OpenGL evolution?
And by the way, why ATI and nVidia don't just take care about OpenGL and ignore that silly ARB? If they can't because of patents and such, they should make a new API from the scratch. Im pretty sure they are more than capable of it.
The problem with OpenGL is that industry users (e.g. CAD and scientific users) are opposed to change in the API which is blatantly against the ethos of the games development community. Industry users have already spent a lot of money on the OpenGL apps, so naturally they don't want the features they use to die. I think that what Khronos has done to date is the most logical route to take given the constraints they are working within.
The ideal solution would be to cut any ties that lead to a conflict of interest and pursue untainted API refreshes as they had originally promised.
As a cross-platform developer I want OpenGL to be a true competitor to D3D, I don't use anywhere near the full feature set of what current versions provide but if it looses at the top end, support will dwindle and the bottom end will also be affected.
If OpenGL even have a chance of competing against DirectX 10, then I'm more than impressed! OpenGL is the way to go for Linux and I and many others with me would like to use Linux as an gaming platform instead of Windows.
I'm very tired of using Windows and I don't like the operating system. It works, but it isn't very fun, unlike Linux which IS a enjoyable experience and feels fast even on old computer hardware, unlike Windows which never get the power it needs.