VT Question

Tips for creating and manipulating planet textures for Celestia.
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PlutonianEmpire M
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VT Question

Post #1by PlutonianEmpire » 10.06.2012, 06:02

One question about VT's in Celestia (1.6.1).

Can a tile of a particular level in a medres/(addon) folder be of a different pixel size than a tile of the same area in the level above or below it?

Such as, can a level9 tile of a particular area be 512x512 pixels while a level10 tile of the same area is 1024x1024 pixels?
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Hungry4info
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Re: VT Question

Post #2by Hungry4info » 10.06.2012, 09:45

I'm pretty sure I've seen this before.
Current Setup:
Windows 7 64 bit. Celestia 1.6.0.
AMD Athlon Processor, 1.6 Ghz, 3 Gb RAM
ATI Radeon HD 3200 Graphics

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t00fri
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Re: VT Question

Post #3by t00fri » 10.06.2012, 11:56

PlutonianEmpire wrote:One question about VT's in Celestia (1.6.1).

Can a tile of a particular level in a medres/(addon) folder be of a different pixel size than a tile of the same area in the level above or below it?

Such as, can a level9 tile of a particular area be 512x512 pixels while a level10 tile of the same area is 1024x1024 pixels?

Answer is YES.

If you observe such varying tile sizes in different levels then most probably my texture tools were used to generate the respective VT set. Note that a given VT, say tx_x_y, of a certain level does NOT refer to the same surface part as tx_x_y does in a different level!

In my texture tools, variable tile sizes are used towards the poles, since for increasing latitude (modulus) , the body's circumference decreases. Hence, smaller tile widths are sufficient at high latitudes to achieve the same resolution level as for near-equatorial latitudes! Or expressed differently: working with a constant tile width at high latitudes would give rise to many unnecessary tile overlaps that represent a vaste of graphics storage, decrease rendering speed and can give rise to rendering instabilities etc.

Variable tile sizes represents one of various optimizations and corrections that can only be found in my texture tools.

Fridger
Last edited by t00fri on 11.06.2012, 17:21, edited 1 time in total.
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John Van Vliet
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Re: VT Question

Post #4by John Van Vliet » 11.06.2012, 03:37

--- edit ---
Last edited by John Van Vliet on 19.10.2013, 05:00, edited 1 time in total.

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Re: VT Question

Post #5by PlutonianEmpire » 11.06.2012, 04:42

john Van Vliet wrote:now what you do NOT want to do is

put 256 x256 tiles in levels 0 to ? 5 in lowres
AND
512x512 tiles in levels 0 to ? 5 in medres
AND have
1024x1024 tiles in liver 0 to ? in hires
Why can't we do that, if I may ask?
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Re: VT Question

Post #6by John Van Vliet » 11.06.2012, 05:25

--- edit ---
Last edited by John Van Vliet on 19.10.2013, 05:00, edited 1 time in total.

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Re: VT Question

Post #7by PlutonianEmpire » 11.06.2012, 05:40

john Van Vliet wrote:because VT's REPLACE the lores,medres,andhires
or
think of it this way
the level0 IS the old "lores"
the level 2and 3 are the old Medres
and the level 3 and up are the hires

there is NO need to have SMALLER versions of level0 in medres and lores
BECAUSE
level0 IS the lores
level1,2 ARE medres
Yeah, that makes a lot more sense now, thanks. :)
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Re: VT Question

Post #8by PlutonianEmpire » 16.06.2012, 21:41

New question:
john Van Vliet wrote:Yes .I do that with the level 0 tiles
i use a 2k image and cut level0 into 1024x1024
then the rest levels are 512

a 1k image in level0 is way WAY too small
this is easier than using "base split"

also you can put a different size in the ctx file
i use 256 ,this causes celestia to move to the higher res image sooner , while zooming in . -- looks better
What would variable pixel sizes look like when looking at, creating, and/or editing .ctx files?

EDIT:
t00fri wrote:
PlutonianEmpire wrote:One question about VT's in Celestia (1.6.1).

Can a tile of a particular level in a medres/(addon) folder be of a different pixel size than a tile of the same area in the level above or below it?

Such as, can a level9 tile of a particular area be 512x512 pixels while a level10 tile of the same area is 1024x1024 pixels?

Answer is YES.

If you observe such varying tile sizes in different levels then most probably my texture tools were used to generate the respective VT set. Note that a given VT, say tx_x_y, of a certain level does NOT refer to the same surface part as tx_x_y does in a different level!

In my texture tools, variable tile sizes are used towards the poles, since for increasing latitude (modulus) , the body's circumference decreases. Hence, smaller tile widths are sufficient at high latitudes to achieve the same resolution level as for near-equatorial latitudes! Or expressed differently: working with a constant tile width at high latitudes would give rise to many unnecessary tile overlaps that represent a vaste of graphics storage, decrease rendering speed and can give rise to rendering instabilities etc.

Variable tile sizes represents one of various optimizations and corrections that can only be found in my texture tools.

Fridger
Do your tools allow images of a certain area rather than the whole globe to be auto-split into smaller tiles?
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Re: VT Question

Post #9by PlutonianEmpire » 16.07.2012, 08:56

New question:

If I cut out a small portion of a main non-VT texture, super-inflate it, and then enhance it, do I still need to apply the latitude stretch, or is it already provided by the texture I cut it from?
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selden
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Re: VT Question

Post #10by selden » 16.07.2012, 13:16

It has already been stretched.
Selden

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Re: VT Question

Post #11by John Van Vliet » 16.07.2012, 21:11

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