Simon Pigot (simon++at++dpiwe.tas.gov.au)
Sat, 02 Oct 1999 16:53:14 +1000
Angus Dorbie wrote sometime back (Fri, 03 Sept) about cliptextures:
> It's an OpenGL extension to support the torroidal scrolling of physical
> texture memory over a larger virtualized texture area. It includes the
> specification of an invalid border surrounding the moving texture memory
> border where paging can occur invisibly at various levels of MIP and
> when rendering if data at a given MIP level is not present the lowest
> available level is used. The actual download uses glsubtexload.
When running the icache and icache_mwin test programs everything appears to work
just fine on hardware such as the good old Crimson RealityEngine :-)
> Performer uses this OpenGL extension and adds fast disk i/o, host memory
> management, multiprocessing, load balancing of downloads and in general
> simple management of the whole process by specifying a CLIP center and
> tweaking a lot of parameters.
>
Looks to me like only the actual pfClipTexture bit requires/uses the appropriate
OpenGL hardware extensions - is this correct? If so, then maybe its possible
(particularly for RealityEngine which doesnt support EXT_texture_lod and thus
bogs down quickly on texture paging) to use the pfImageCache to drive a
high-detail texture tile across a paging ASD. I can do a tile of 1024x1024 with
a RM4(s) (and 2048x2048 with RM5(s)) in the Crimson RE. Any reason why this
wouldnt work? Obviously I'm not expecting 30 frames/sec but 10 frames/sec would
be nice enough especially since (a) its unlikely that we'll ever have an
InfiniteReality of any kind down here (much as we'd like to have one) (b) paging
ASDs of quite high detail already work nicely (given its age) on Crimson RE.
Cheers,
Simon
This archive was generated by hypermail 2.0b2 on Fri Oct 01 1999 - 23:50:45 PDT