From what I can see, Displacement mapping under OpenGL is done via uber/super buffers, which are exposed on the R300/R350 line of cards.
However, I cannot for the life of me actually find any information regarding using the extensions to handle displacement mapping. Does anyone have any links to information in regards to this, or have any information themselvse on it?
AFAIK displacement-mapping is only available on Matrox cards at the moment. Don“t know, if they have an OpenGL extension for it (i“ve never seen one). You should check out their pages for more information.
Jan.
GLIM - Immediate Mode Emulation for GL3
I was asking about the use of them on the r300/r350 based cards specifically, which do support it (its a DX9 feature after-all, and the D3D demos of it run fine).
I understand that the uber/super buffers are still not finalized, however the current spec of them is implemented in the ATi drivers from what Ive seen, and I was hoping to find some info on them.
ATI and NVIDIA seem to have a paper about SuperBuffers, perhaps it's explained there, how to use it.
see you,
Azrael
[This message has been edited by Azrael (edited 07-08-2003).]
Bush is on a highway to hell with the whole world blind leading it straight into the flames of hell.
Ive read those, an the most info they contain about how to use it under OpenGL is that you need to use UberBuffers to do so. Nothing more.
It's a two-step process: You have to use a fragment program to render to a floating point buffer, and then use that floating point buffer as a vertex buffer.Originally posted by DopeFish:
Ive read those, an the most info they contain about how to use it under OpenGL is that you need to use UberBuffers to do so. Nothing more.
You supply your geometric data as input to the fragment program and you issue texture reads for the displacement mapping part (you can do it adaptive or not).
The generation of the vertex data is just rasterising a rectangle. The fragment program will be run for each component of the fp buffer et voilą
This is a generic technique, you can use it to generate vertices based on any kind of data (NURBS anyone?).
Heck, you don't even need to generate vertices at all, you can generate any kind of data (physics, photon maps, etc).
[This message has been edited by evanGLizr (edited 07-09-2003).]
There is an Effect-Demo at the ATI-Dev-Websites wich includes source-code for displacement-mapping in directx. http://meshuggah.4fo.de/
mfG
Baerbel
Thnx for the replies.
I can see its going to take me a while to get my head around uber buffers
It seems like a lot of fragment calculations if you want adaptive generation. is it even possible?
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