Matthew Whitaker (mattw++at++syd.csa.com.au)
Thu, 10 Dec 1998 09:02:21 +1100
First of all, thanks (belatedly) for the earlier confirmations of my
query regarding multipipe clip textures.
I have some further questions however, and I'd appreciate any light that
people are able to shed.
1) I have read /usr/share/Performer/doc/clipmap/HowToDoVirtual.html
and /usr/share/Performer/doc/clipmap/IRClipmapBugs.html.
These documents are dated 06/10/97 & 11/12/97 respectively, and appear
to be draft versions. Do more up to date versions exist?
2) My understanding is that virtual clipmaps of up to 24 levels (8M*8M)
are directly supported by InfiniteReality/Performer, but this can be
increased to 31 levels (1G*1G) by applying the workaround described in
section 1.5 of the bugs document. Is this correct? If so, is it an
effective approach, or is it a more high-risk strategy, of limited
benefit? I am very interested to know of previous experiences in this
area.
By way of background, I am part of a two man team preparing the visual
database of a helicopter flight simulator being built for the Royal
Australian Navy. I am currently investigating the use of a single
cliptexture to cover the whole of the Australian subcontinent, and if my
calculations are correct then an 8M*8M texture is sufficient to give a
maximum resolution of 0.5m/texel (approximately). Away from the insets,
the maximum resolution is likely to be of the order of 5-10m/texel. I am
planning on using 2byte texels, 512 texel tiles, and a 1024texel
clipsize (the only combination that seems to fit into the 64Mb Texture
Memory).
The texture size that we finally choose is mainly dependent on the
quality of the imagery that we can obtain. However, I need to be
confident that if we can obtain photography that gives resolutions of
0.2m/texel (or higher?!), then our cliptexture solution will be flexible
enough to take advantage of it - but this implies a need for a 25-26
level cliptexture.
The use of multiple (smaller) cliptextures doesn't appear be an
effective solution to the problem, as Texture Memory resources appear to
be consumed very rapidly. However, I have to admit that I haven't
considered this alternative in detail as yet.
Any advice or information that people can give will be appreciated!
-- Regards,Matthew Whitaker
Computer Sciences Corporation ph: +61 2 9901 1633 460 Pacific Highway fax: +61 2 9901 1555 St Leonards, NSW 2065, Australia. email: mwhitak2++at++csc.com.au
Hi,
First of all, thanks (belatedly) for the earlier confirmations of my query regarding multipipe clip textures.
I have some further questions however, and I'd appreciate any light that people are able to shed.
1) I have read /usr/share/Performer/doc/clipmap/HowToDoVirtual.html
and /usr/share/Performer/doc/clipmap/IRClipmapBugs.html.These documents are dated 06/10/97 & 11/12/97 respectively, and appear to be draft versions. Do more up to date versions exist?
2) My understanding is that virtual clipmaps of up to 24 levels (8M*8M) are directly supported by InfiniteReality/Performer, but this can be increased to 31 levels (1G*1G) by applying the workaround described in section 1.5 of the bugs document. Is this correct? If so, is it an effective approach, or is it a more high-risk strategy, of limited benefit? I am very interested to know of previous experiences in this area.
By way of background, I am part of a two man team preparing the visual database of a helicopter flight simulator being built for the Royal Australian Navy. I am currently investigating the use of a single cliptexture to cover the whole of the Australian subcontinent, and if my calculations are correct then an 8M*8M texture is sufficient to give a maximum resolution of 0.5m/texel (approximately). Away from the insets, the maximum resolution is likely to be of the order of 5-10m/texel. I am planning on using 2byte texels, 512 texel tiles, and a 1024texel clipsize (the only combination that seems to fit into the 64Mb Texture Memory).
The texture size that we finally choose is mainly dependent on the quality of the imagery that we can obtain. However, I need to be confident that if we can obtain photography that gives resolutions of 0.2m/texel (or higher?!), then our cliptexture solution will be flexible enough to take advantage of it - but this implies a need for a 25-26 level cliptexture.
The use of multiple (smaller) cliptextures doesn't appear be an effective solution to the problem, as Texture Memory resources appear to be consumed very rapidly. However, I have to admit that I haven't considered this alternative in detail as yet.
Any advice or information that people can give will be appreciated!
-- Regards, Matthew Whitaker Computer Sciences Corporation ph: +61 2 9901 1633 460 Pacific Highway fax: +61 2 9901 1555 St Leonards, NSW 2065, Australia. email: mwhitak2++at++csc.com.au
This archive was generated by hypermail 2.0b2 on Wed Dec 09 1998 - 14:15:46 PST