[Therion] Loch: maximum resolution of image?

Bruce dangle at tomo.co.nz
Tue Apr 27 22:42:46 CEST 2010


Somewhat unrelated perhaps...
Some time ago I prepared three somewhat identical image files, composite
aerial photographs, about 6 x 8.5 km coverage, 
100 dpi gave 11MB image 3312 x  4681 pixels
150 dpi gave 18MB image 4967 x  7021 pixels
300 dpi gave 51MB image 9934 x 14042 pixels

All but the smallest exceed the 4096 limit.
These resulted in similar sized loch files.  They all take a reasonable time
to load, no errors produced.  The interesting thing is that the 50MB one
produces a model as black as the inside of Hotblack Deseartos spaceship.  Ie
nothing is displayed, not even the grey terrain model.  Some sort of
overload, or too much scaling perhaps? (Any caves imported over top of this
are displayed correctly however -viewed just now with 5.3.1, it was created
with whatever was current in Sept 2009).
Maybe related to your file locations issue Wolfgang?  Perhaps not?

It would be nice to squeeze some more resolution out of Loch, but then I
guess these 3D models are not necessarily suited to the detailed inspection
or interrogation that a high resolution implies.

Regards
Bruce

-----Original Message-----
From: therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] On Behalf
Of Wolfgang Zillig
Sent: Wednesday, 28 April 2010 7:48 a.m.
To: therion at speleo.sk
Subject: Re: [Therion] Loch: maximum resolution of image?

Hello Stacho,

thanks for your answer. Now I reduced the overlay image to 5000x5000 
pixel. Still bigger than the 4096 but as I don't know 
GL_MAX_TEXTURE_SIZE it will be rescaled anyhow. File size is also 
smaller and it loads significantly faster.

The question arose as I have access to a workstation with a quite good 
grafics card and if it would be possibe to use the full resolution... 
Anyhow the model looks nice now.

I have another strange problem: the model gets loaded without surface 
texture (only gray height field) when I open the lox file on my external 
hard disk or from C:\temp. On the "desktop" it shows correct. Any idea?

Best regards
Wolfgang




Am 27.04.2010 13:49, schrieb Stacho Mudrak:
> Hi Wolfgang,
>
> texture image size is limited by your hardware (GL_MAX_TEXTURE_SIZE
variable
> returned by OpenGL) or 4096x4096 max. But if your input image is larger,
it is
> scaled down. There is no limit on elevation model, but with some high
density,
> there may be performance problems.
>
> Best regards, S.
>
> Quoting Wolfgang Zillig<wolfgang.zillig at web.de>:
>
>    
>> Hi,
>>
>> I once read somewhere that the overlay size is limited. Can anyone tell
>> me where this limit is and where it could be changed (is it hard coded
>> or hidden in a ini-file)? Is there something similar for the elevation
>> model?
>>
>> Many thanks
>> Wolfgang
>> _______________________________________________





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