[Opensim-users] Heightmap Grayscale % = ??? Meters?

Sun May 6 14:56:45 UTC 2012

Thanks for the suggestion. That sparked my curiosity as well. So
while in-world I accessed the console and entered "terrain fill 20" and
then I entered "terrain save watertest.png" 

Using my color picker, the
actual color of the saved PNG from OpenSim was a grayscale value of 15
(RGB 39,39,39) whereas the one I'd created and imported was a value of
20 (RGB 51,51,51) which came to 25.75 meters. 

Using GiMP, I just
created a fresh new heightmap with a value of 15 and it imported
(terrain load newtest.png) at 20 meters spot-on. 

So in practice I see
a reliable method, but wonder why the values are odd... 

What I aim to
do then, at least as a work around for now, is to set the terrain
in-world to the four heights I require (21 meters, 28 meters and 35
meters), then export each, define the grayscale values, then create my
final heightmap with designated areas using those grayscale percentages.

Thanks for at least helping me to view things from an alternative
perspective. It should work this way. but anyone whow WHY grayscale
values do NOT correspont with precise heights like they are supposed to?

I know that in Second Life you cannot (in theory) create any elevation
anywhere above 255 meters because that is pure white on a grayscale...

Thanks all. 

On 05/06/2012 09:23, Gudule Lapointe wrote: 

> The
question may be 20 "what?" on your image. 
> Depending of your software
and the kind of color you choose, it can be counted in percent or in
0-255 scale. 
> What I did when I encountered the same problem was
setting the terrain in world, saving the height map and checking the
value. If I remember well, 20meters ended up to be something around 16%
grey (which does not find any of the two hypothesis above) 
> I didn't
have the curiosity to match the result with OpenSim settings about
minimum and maximum terrain height. This could be the clue. 
> 
> -- 
>
http://www.speculoos.net/ [4] 
> secondlife://speculoos.net:8002/ 
>
Speculoos, the belgian cookie-flavored metaverse 
> 
> Le 6 mai 2012 à
16:00, Len W. Brown a écrit : 
> 
>> Ah yes, thanks for the trip down
memory lane! I remember seeing that over a year back while still pretty
active in Second Life. 
>> 
>> Although it hasn't been updated since
August of last year, it has helped answer a few of my other questions,
however, on the page I am reminded that I continue to be doing something
wrong, or else Second Life's servers are better calibrated, because I am
reading: 
>> 
>> Remember that the water level has a default elevation
of 20 meters (with a corresponding gray value of 20), and that an estate
owner can change this setting in-world. 
>> 
>> And while this is my
objective, the actual height I'm getting in-world is not accurate.
Unless maybe by using PNG rather than importing a RAW-generated terrain
that is where my trouble stems maybe? 
>> 
>> Thanks again! 
>> 
>> On
05/06/2012 08:23, R.Gunther wrote: 
>> 
>>> Not sure if you found this
one. But here you can find lots of info about Secondlife heightmaps.
>>>
http://wiki.secondlife.com/wiki/Tips_for_Creating_Heightfields_and_Details_on_Terrain_RAW_Files
[2]
>>> 
>>> On 2012-05-06 15:04, Len W. Brown wrote: 
>>> 
>>>> Hi
everyone! Google and OpenSimulator.org [1] haven't provided me a really
clear direct answer to this question (yet)... 
>>>> 
>>>> I am
attempting to create a very crisp heightmap for a tech-based region I'm
planning where certain areas must be at precise elevations. I'm trying
to choose precise grayscale colors that result in precise elevations.

>>>> 
>>>> I'm having a hard time determining what settings to choose.

>>>> 
>>>> I'm using GiMP and have made multiple attempts this morning
creating an image 256X256, grayscale, set to total black and saved as a
PNG with zero compression. But when loading in the console ("terrain
load 0.png" for example) while it loads "successfully" what I wind up
with is a flat terrain that is approximately 12.25 meters in elevation.
Not the 0 meters I expected. 
>>>> 
>>>> Doing the same as above, but
setting the grayscale to 20 on a new image, I expected it to load at
sealevel. Instead it loaded at about 25.75 meters elevation. 
>>>> 
>>>>
I would sincerely appreciate a clear options setting for elevation if
this is actually supported with precision in OpenSim 0.7.3.1... Thanks!

>>>> 
>>>> -- 
>>>> 
>>>> - Len W. Brown
>>>> len at lenwbrown.com
>>>>

>>>> _______________________________________________
>>>> Opensim-users
mailing list
>>>> Opensim-users at lists.berlios.de
>>>>
https://lists.berlios.de/mailman/listinfo/opensim-users
>> 
>> -- 
>>

>> - Len W. Brown
>> len at lenwbrown.com
>> www.lenwbrown.com
>>
_______________________________________________
>> Opensim-users mailing
list
>> Opensim-users at lists.berlios.de [3]
>>
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-- 

- Len W.
Brown
 len at lenwbrown.com
 www.lenwbrown.com

Links:
------
[1]
http://OpenSimulator.org
[2]
http://wiki.secondlife.com/wiki/Tips_for_Creating_Heightfields_and_Details_on_Terrain_RAW_Files
[3]
mailto:Opensim-users at lists.berlios.de
[4] http://www.speculoos.net/
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