Mark Aubin (aubin++at++mustang.engr.sgi.com)
Thu, 13 May 1999 09:12:02 -0700 (PDT)
Each of these will take approx 17.33MB giving a total of approx 69.32MB.
The internal formats always have to use an even number of bytes, so if
you use RGB_8 or RGBA_8, it still uses 4 bytes per texel. The only
way to get this smaller is to use a packed pixel format, such as
the RGB5_A1, which only uses two bytes per texel.
For a clipsize of 1024 x 1024, texel size of 4 bytes, and
virtual size of 8192 x 8192, this is how the usage is figured:
Number of clipped levels = 3 (2K, 4K, 8K)
Size of clipped levels = 1024 * 1024 * 4 = 4194304
Tex mem of clipped levels = 4194304 * 3 = 12582912
Tex mem of non-clipped levels = 1024 * 1024 * 4 * 4/3 = 5592405.3333
Total tex mem = 12582912 + 5592405.3333 = 18175317.3333 bytes
BTW - if you were using ClipGen to generate this clipmap, you
would have a handy little "Texture Memory Used:" box showing
you this number instantly as you changed the clipsize,
internal texture size, virtual size, etc.
--Mark Aubin
On May 13, 3:28pm, Performer-ML wrote:
> Subject: several cliptextures
> Hello all,
>
> I'd like to use 4 different cliptextures simultaneously.
> 2 are RGB_8, and other 2 are RGBA_8.
>
> When I use 3 cliptextures, it works fine, but I use 4 or more
> cliptextures, framerate(draw-speed) extremely grows worse...
>
> Each cliptextures is under following condition (from .ct file).
>
> ext_format PFTEX_PACK_8
> int_format PFTEX_RGB_8
> img_format PFTEX_RGB
> virt_size 8192 8192 1
> clip_size 1024
> invalid_border 16
> smallest_icache 64 64 1
> icache_format nhk_l.%d.ic
> icache_params
> PFCLIPTEX_FNAMEARG_LEVEL_SIZE
> tile_format nhk_l.%d.0.0.raw888
> tile_params
> PFCLIPTEX_FNAMEARG_LEVEL_SIZE
>
> and max-tilesize is 512x512.
>
> virt_size-8192 and clipsize-1024 are indispensable.
> If it's possible, I need clipsize-2048 because output is HDTV.
>
> Is it possible to optimize anything or should I reduce the number
> of cliptextures?
>
> Thank you,
> --
> M.Y.
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>-- End of excerpt from Performer-ML
This archive was generated by hypermail 2.0b2 on Thu May 13 1999 - 09:12:11 PDT