Phil Keslin (philk++at++cthulhu.engr.sgi.com)
Wed, 18 Aug 1999 11:38:42 -0700
The command to do the conversion is
imgcopy -p 512,512 Nowra.rgb Nowra.fit
Also, are you using pyramid files? They will save the intermediate
levels of your inset images to disk for later reuse and should help with
any thrashing. With your large page sizes and memory limitations, it is
probably regenerating each intermediate level.
- Phil
mwhitak2++at++csc.com wrote:
>
> Hi.
>
> I have been using clipgen to generate small cliptextures with some success. I am
> now attempting to use it to build larger, more complex cliptextures and seem to
> have hit a serious performance problem.
>
> Any assistance you can provide will be appreciated, as the alternatives that I
> am considering appear to be extremely labour intensive. Although at the moment I
> am attempting to construct a cliptexture from a single image file, in the future
> this image file will form a higher resolution inset to a low res. satellite
> image covering a large area, and will itself be the parent of an even higher
> resolution inset. For this reason, I much perfer to be able to use a tool that
> can construct such a hierarchy, rather than build the thing by hand.
>
> Here is the clipgen parameters file that I am using:
>
> (See attached file: copy_of_Nowra.cp)
>
> This attempts to create a clip texture from a single inset file (Nowra.rgb,
> approx 4.0Gb), the details of which are given below:
>
> lionel 13:31:12 35> imginfo Nowra.rgb
> Image file: Nowra.rgb
> File format: Classic SGI image
> Dimensions (w,h,z,c): 34858, 41972, 1, 3
> Page Size (w,h,z,c): 34858, 1312, 1, 3
> Data type: unsigned char
> Dimension order: interleaved
> Color model: RGB
> Coordinate space: lower-left
> Statistical Min/Max: 0 - 255
> Display Min/Max: 0 - 255
>
> I have generated the highest resolution level (L65536), and using icache this
> seems to be complete and correct.
> This level consists of a total of 16384 tiles and took approximately 5 days to
> generate using an O2 (approx 30s /tile), However the next level down (L32768)
> appears to be running extremely slow, taking approximately 10m /tile.
>
> With roughly 5000 tiles remaining before the texture is completed, I am faced
> with an apparent wait of 1 month, which is obviously unacceptable!
>
> Am I doing something wrong? Or is there some algorithmic compromise that
> accounts for these delays?
>
> As well as running clipgen on my O2, I have also tried running it as root on a 4
> CPU Onyx2 with 512Mb RAM and 5Gb swap. Even here, there does not appear to be
> any significant improvement in performance and all system resources appear to be
> under-utilised, i.e. it does not appear to be I/O or CPU bound.
>
> Both machines are running IRIX 6.5 and performer v2.2.1
>
> As I said before, any useful advice is appreciated!!
>
> Regards,
> Matthew Whitaker
> __________________________________________________
> 3D Database Modeller - ANZAC Ship Helicopter Project
> CSC
> 460 Pacific Hwy, St Leonards NSW 2065 Australia
> Ph: +61-2-9901-1633 Fax: +61-2-9901-1110 Email: mwhitak2++at++csc.com.au
>
> ------------------------------------------------------------------------
> Name: copy_of_Nowra.cp
> copy_of_Nowra.cp Type: unspecified type (application/octet-stream)
> Encoding: base64
-- Phil Keslin <philk++at++engr.sgi.com>
This archive was generated by hypermail 2.0b2 on Wed Aug 18 1999 - 11:38:49 PDT