Sign in with
Sign up | Sign in
Your question

Land class scenery

Last response: in Video Games
Share
Anonymous
April 13, 2005 10:38:31 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Hello all...

First of all can someone define what land class scenery is?

Secondly, is it available, freeware or payware, for the UK?

thanks!!

Colin Bear

More about : land class scenery

April 13, 2005 2:03:24 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

On Wed, 13 Apr 2005 06:38:31 +0000 (UTC), "Colin Bear"
<colin(nospam)bear@btinternet.com> brought the following to our
attention:

>Secondly, is it available, freeware or payware, for the UK?

there's a U.K. land class folder installed here.. but no readme.txt or
zip archive. It contains 49 files that zip to 94k. All the filenames
have.. " _VRPs.bgl " in them. It's for FS8 however. :[


-Gregory
Anonymous
April 13, 2005 2:21:14 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

.... there came a great "Colin Bear" <colin(nospam)bear@btinternet.com>
flying, and he bore tidings beyond hope, crying:

>Hello all...
>
>First of all can someone define what land class scenery is?

landclass scenery tells the flight simulator where to put which type
of groudntexture (urban, desert, forest, ...)

--
"This is an extremely primitive and paranoid culture."
(James T. Kirk on 20th century America, Star Trek IV)
Related resources
Can't find your answer ? Ask !
April 13, 2005 2:57:27 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

On Wed, 13 Apr 2005 10:03:24 -0400, Gregory
<flightsim.maps@bkwds.comcast.net> brought the following to our
attention:

>On Wed, 13 Apr 2005 06:38:31 +0000 (UTC), "Colin Bear"
><colin(nospam)bear@btinternet.com> brought the following to our
>attention:
>
>>Secondly, is it available, freeware or payware, for the UK?
>
>there's a U.K. land class folder installed here.. but no readme.txt or
>zip archive. It contains 49 files that zip to 94k. All the filenames
>have.. " _VRPs.bgl " in them. It's for FS8 however. :[
>
>
> -Gregory

oops.. sorry these files are for UK NavAids.. FS2002 / 04
by Martin A McCormick

It's another mistake or example of disorganization in the Scenery
configuration / folder structure. should not be in land class section
but in other scenery folder.. and with clear, self explanatory folder
name!! :) 

-Gregory
Anonymous
April 14, 2005 1:56:20 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

"Colin Bear" <colin(nospam)bear@btinternet.com> wrote in news:D 3iep6$n36
$1@titan.btinternet.com:

> Hello all...
>
> First of all can someone define what land class scenery is?
>

Landclass is based on the geography concept that it is possible
to characterize the earth surface by vegetation, soil, and
built environment variations. This concept is useful to
geographers, biologists, etc.

For flight sim, there is the concept that earth surface has
a visual appearance from the air that corresponds to the
idea of land class. That is, it is possible to define types
of land cover that appear the same from the air.

So, FS9 has obtained, or built, a model of the entire earth that
has assigned land classifications with a surface resolution of
about 1.2 km square. This information is contained in the default
file worldlc.bgl. This file assigns integer values of 0 - 255
(not all are used in FS9) so there is a possibility of 256 different
land classifications which could be assigned.

FS9 uses the integer to map to a set of files in world\texture which
represent the texture to be applied for that land class value. In
addition to the texture file, 3D generic objects (called autogen)
are tied to the files, to provide greater realism.

In theory, it would only take 256 different texture files to serve the
intended purpose, but this would be unsatisfactory for a couple reasons:

1. Night. At night there is little ambient lighting (though moonshine
could be depicted) but there is artificial surface lighting. So this is
modeled by having a set of night textures. These are blended in at
dusk/dawn.

2. Seasons. In temperate zones, there can be a great deal of visual
difference based on seasonal effects. FS9 uses a file seasons.bgl to
select from a set of seasonal textures based on location and date.

3. Cultural effects. Land with human impacts (intensive agriculture
or habitation) has a different visual appearance due to cultural
differences. FS9 has a file reagons.bgl to select culturally-modified
texture variations.

4. Checkerboard effect. When viewed from the air, the terrain textures
at 1.2 km resolution would suffer from a tiling effect as the edge of
each texture would be apparant, and the repeating nature of each tile
(where several identical textures are placed side-by-side) would also
reduce realism. FS9 attempts to get around this by having a set of
textures with some visual variation, and the textures are blended with
their neighboring textures on each of the 4 sides.

5. Performance issues. Note that the textures have default size of
256x256 pixels, but scenery displayed at a distance from the viewer
doesn't need this level of accuracy, and so smaller versions
(128x128, 64x64, etc) versions of each texture are stored and used in
the distance.

So, there a couple of ways to modify the land class system to change
visual appearance. These can be summarized as:

1. Modify the worldlc.bgl to change the land classification value for
a given position. This is what is commonly referred to as "land class"
file.

2. Modify the textures in world\texture. The modified textures can
have a different visual appearance, and also have different autogen
objects assigned.

3. Modify the land class integer mapping system through seasons.bgl,
regions.bgl, and lclookup.bgl. To the best of my knowledge, no one
has successfully done this.

Note that there is also a complementary system (though simpler) to
deal with the visual appearance of water bodies. Also, the land class
derived textures are modified by drawing terrain features over them
(airport and park ground textures, roads, railroads, streams, etc).
Finally, land class can be over-ridden by phototextures.

scott s.
..
April 14, 2005 3:07:51 AM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

Best description I have ever read. Many thanks for your efforts, Scott.

Arthur

"scott s." <75270_3703a@csi.xcom> wrote in message
news:Xns96377970FA702752703703acsicom@207.217.125.201...
> "Colin Bear" <colin(nospam)bear@btinternet.com> wrote in news:D 3iep6$n36
> $1@titan.btinternet.com:
>
>> Hello all...
>>
>> First of all can someone define what land class scenery is?
>>
>
> Landclass is based on the geography concept that it is possible
> to characterize the earth surface by vegetation, soil, and
> built environment variations. This concept is useful to
> geographers, biologists, etc.
>
> For flight sim, there is the concept that earth surface has
> a visual appearance from the air that corresponds to the
> idea of land class. That is, it is possible to define types
> of land cover that appear the same from the air.
>
> So, FS9 has obtained, or built, a model of the entire earth that
> has assigned land classifications with a surface resolution of
> about 1.2 km square. This information is contained in the default
> file worldlc.bgl. This file assigns integer values of 0 - 255
> (not all are used in FS9) so there is a possibility of 256 different
> land classifications which could be assigned.
>
> FS9 uses the integer to map to a set of files in world\texture which
> represent the texture to be applied for that land class value. In
> addition to the texture file, 3D generic objects (called autogen)
> are tied to the files, to provide greater realism.
>
> In theory, it would only take 256 different texture files to serve the
> intended purpose, but this would be unsatisfactory for a couple reasons:
>
> 1. Night. At night there is little ambient lighting (though moonshine
> could be depicted) but there is artificial surface lighting. So this is
> modeled by having a set of night textures. These are blended in at
> dusk/dawn.
>
> 2. Seasons. In temperate zones, there can be a great deal of visual
> difference based on seasonal effects. FS9 uses a file seasons.bgl to
> select from a set of seasonal textures based on location and date.
>
> 3. Cultural effects. Land with human impacts (intensive agriculture
> or habitation) has a different visual appearance due to cultural
> differences. FS9 has a file reagons.bgl to select culturally-modified
> texture variations.
>
> 4. Checkerboard effect. When viewed from the air, the terrain textures
> at 1.2 km resolution would suffer from a tiling effect as the edge of
> each texture would be apparant, and the repeating nature of each tile
> (where several identical textures are placed side-by-side) would also
> reduce realism. FS9 attempts to get around this by having a set of
> textures with some visual variation, and the textures are blended with
> their neighboring textures on each of the 4 sides.
>
> 5. Performance issues. Note that the textures have default size of
> 256x256 pixels, but scenery displayed at a distance from the viewer
> doesn't need this level of accuracy, and so smaller versions
> (128x128, 64x64, etc) versions of each texture are stored and used in
> the distance.
>
> So, there a couple of ways to modify the land class system to change
> visual appearance. These can be summarized as:
>
> 1. Modify the worldlc.bgl to change the land classification value for
> a given position. This is what is commonly referred to as "land class"
> file.
>
> 2. Modify the textures in world\texture. The modified textures can
> have a different visual appearance, and also have different autogen
> objects assigned.
>
> 3. Modify the land class integer mapping system through seasons.bgl,
> regions.bgl, and lclookup.bgl. To the best of my knowledge, no one
> has successfully done this.
>
> Note that there is also a complementary system (though simpler) to
> deal with the visual appearance of water bodies. Also, the land class
> derived textures are modified by drawing terrain features over them
> (airport and park ground textures, roads, railroads, streams, etc).
> Finally, land class can be over-ridden by phototextures.
>
> scott s.
> .
>
Anonymous
April 15, 2005 4:38:51 PM

Archived from groups: alt.games.microsoft.flight-sim (More info?)

On Wed, 13 Apr 2005 21:56:20 GMT, "scott s." <75270_3703a@csi.xcom>
wrote:

>Landclass is based on the geography concept that it is possible
>to characterize the earth surface by vegetation, soil, and
>built environment variations. This concept is useful to
>geographers, biologists, etc.

Thanks for all that, Scott - certainly a post to keep.

James
!