Cloud texture

Tips for creating and manipulating planet textures for Celestia.
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Nibla
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Cloud texture

Post #1by Nibla » 15.02.2013, 10:49

Hi, I'm trying to find a good cloud texture for Earth, and I found one that I like. The problem is though that the clouds are drawn on a black background. Is there anyway to remove the black bakcground without hurting the clouds? I'm going to give you an example of what I mean, but this is NOT the picture I want to use.

Image

:wink:
^_^

MiR
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Re: Cloud texture

Post #2by MiR » 15.02.2013, 14:20

If you are using photoshop (maybe an older version) or software which can handle .8bf files search for "elimblac.8bf".
The plugin deletes every black area of your image by using the Alpha-Channel.

Michael

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Nibla
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Re: Cloud texture

Post #3by Nibla » 15.02.2013, 19:08

MiR wrote:If you are using photoshop (maybe an older version) or software which can handle .8bf files search for "elimblac.8bf".
The plugin deletes every black area of your image by using the Alpha-Channel.

Michael
I have Photoshop (CS6 and CS5) but can't find the plugin. The file is a normal .jpg-file.
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selden
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Re: Cloud texture

Post #4by selden » 15.02.2013, 19:56

A typical cloud texture for Celestia contains a primary image which is entirely white and an 8bit alpha layer which is grey-scale -- similar to the image that you show. The first thing that you need to do is remove the grey continents from the image (e.g. make them black), then reduce it to an 8bit image, and then insert it into a 32bit PNG as its alpha channel.

These steps are relatively straight-forward when using a command-line image manipulation program like ImageMagick's utility convert.
Selden

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Fenerit M
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Re: Cloud texture

Post #5by Fenerit » 15.02.2013, 21:45

Nibla wrote:
MiR wrote:If you are using photoshop (maybe an older version) or software which can handle .8bf files search for "elimblac.8bf".
The plugin deletes every black area of your image by using the Alpha-Channel.

Michael
I have Photoshop (CS6 and CS5) but can't find the plugin. The file is a normal .jpg-file.

elimblac doesn't seem exist anymore. BUT: you can download the eliminate white from here:
http://www.edesign.com/filters/
and does invert the image. Blacks will be white and whites will be black. Once removed the white, do invert the image again.
Note that you need of the file msvcrt10.dll, because is an old DLL which M$ has removed from the OS's installation. The DLL and the instruction are here:
http://thepluginsite.com/products/picopro/tutorials/makework.htm

BTW:
sound weird to me that CS6/CS5 doesn't have a color-to-alpha option like GIMP... Note that like Selden says, you must make a layer from the JPG, the plugin doesn't work on a plain background image.
Never at rest.
Massimo

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Nibla
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Re: Cloud texture

Post #6by Nibla » 16.02.2013, 12:10

Fenerit wrote:
Nibla wrote:
MiR wrote:If you are using photoshop (maybe an older version) or software which can handle .8bf files search for "elimblac.8bf".
The plugin deletes every black area of your image by using the Alpha-Channel.

Michael
I have Photoshop (CS6 and CS5) but can't find the plugin. The file is a normal .jpg-file.

elimblac doesn't seem exist anymore. BUT: you can download the eliminate white from here:
http://www.edesign.com/filters/
and does invert the image. Blacks will be white and whites will be black. Once removed the white, do invert the image again.
Note that you need of the file msvcrt10.dll, because is an old DLL which M$ has removed from the OS's installation. The DLL and the instruction are here:
http://thepluginsite.com/products/picopro/tutorials/makework.htm

BTW:
sound weird to me that CS6/CS5 doesn't have a color-to-alpha option like GIMP... Note that like Selden says, you must make a layer from the JPG, the plugin doesn't work on a plain background image.
The plugin does not seem to work. I have 64-bit on both Photoshop.
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John Van Vliet
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Re: Cloud texture

Post #7by John Van Vliet » 17.02.2013, 02:26

--- edit----
Last edited by John Van Vliet on 18.10.2013, 11:43, edited 1 time in total.

Topic author
Nibla
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Re: Cloud texture

Post #8by Nibla » 17.02.2013, 16:07

john Van Vliet wrote:the image in the first post is from X-Planet
and is rather small ( as i recall the free version is 2048x1024 )
http://xplanet.sourceforge.net/clouds.php
-- the daily automated build , for today--
http://xplanet.sourceforge.net.nyud.net ... s_2048.jpg
the large 43200x21600 Bluemarble cloud map is here
ftp://neo.sci.gsfc.nasa.gov/bluemarble/

a very good and free GPL program for working with transparency is " The Gimp "

for this example i will use the above XPlanet map

just a few mouse clicks and it is done
Image
first convert the grayscale image to RGB
"image" > "mode" and click on the RGB radio button
then click on
"color" and select "color to alpha
Image
( the default is white -- #FFFFFF )
change the color to black -- #000000
-- the "checkerboard" represents the transparent area
then
Image
"file" > "export" and save AS A png IMAGE !!!
jpg dose NOT support a transparency
Works great! Thank you so much! :wink:
^_^


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