On Jan 4, 2008 2:16 AM, Alexander Toresson <alexander.toresson@gmail.com> wrote:
On Jan 4, 2008 1:55 AM, R. Aditya Kadambi <rakadambi@gmail.com> wrote:
> Hi;
>
> I am trying do hardware accelerated volume rendering with 3D textures using
> a scenegraph called OpenRM(www.openrm.org). The program is called vrend
> which uses 3D textures
>  to HW render 3D raw data.
>
> I am using ATI X9250 (R200) card. I am trying to render two sets of raw
> data. The smaller one which is 64x64x64 is successfully rendered with 3D
> textures with r200 driver. The bigger volume which is 256x64x256 only
> appears to be rendered in "half" along the z axis. The other half appears as
> garbage.
>
> I put in a call for 3D texture size and it comes as 256 (which probably
> means I can render a 256x256x256 cube??).
>
> I was able to successfully Software render it on Mesa. It renders fine.
> Furthermore, it is rendered fine with the ATI proprietary driver (V 8.28.8)
> (surprise! surprise!).
>
> This makes me suspect the r200 driver. Is there an inherent limitation or a
> bug or a missing feature in the driver (r200/mesa) which might cause this.
> Is there any way for me to compile mesa with debug flags to test this? Or is
> there a bug in the lower level ati driver?
>

The r200 has a hardware-limitation of 2048x2048 for 2d textures. I'm
not sure, but this problem might be related to that.

Is this limit imposed by the driver for some reason? because, the card does render bigger volumes through proprietary driver. Furthermore, it says the
3D texture size is 256x256x256, which is higher then the volume  I am trying to render.

Thanks,
Aditya