Selden's Billboard Meshes for Celestia
Contents
Introduction
Billboard \Bill"board`\, n.
1. (Naut.) A piece of thick plank, armed with iron plates,
and fixed on the bow or fore channels of a vessel, for the
bill or fluke of the anchor to rest on. --Totten.
2. A flat surface, as of a panel or of a fence, on which
bills are posted; a bulletin board.
Here is a simple, square 3DS object model. By changing its surface
texture image map, you can use it to show flat, colorful pictures of
deep space objects in Celestia. It's a billboard in space!
Celestia v1.3 and later let you create Deep Space Catalogs (.DSC
files). You can use them to define the locations of Nebulae.
They consist of 3D models with appropriate shapes and surface textures.
Unfortunately, making a three dimensional shape
that looks right from all directions can be rather difficult.
We only know what most nebulae look like from here on Earth.
We really don't know what their other sides look like.
Radio telescopes have provided hints about some of their shapes, though.
This flat "billboard" lets you display a photograph instead of a
three dimensional shape. The picture will only look right in Celestia
when seen from the vicinity of the
Earth, of course. If you travel far away from the Earth, it'll be
distorted.
1.0: The Flat Billboard.
- billboard.3ds (1KB, 5April2003)
This 3DS model is a flat, square object that can hold any picture
you want to display in Celestia.
The zip archive below includes the 3DS billboard object and a sample
billboard image. The 3DS object itself is less than 1KB. The ZIP file
is much larger because of the size of the sample image and its alpha
channel.
- billboard.zip (1.1MB, updated 21May2003
with a more accurate orientation for Hoag's Object)
Archive: billboard.zip
Length Date Time Name
-------- ---- ---- ----
365 06-18-03 10:47 billboard/billboard.dsc
55215 06-18-03 10:46 billboard/billboard.html
0 05-21-03 20:16 billboard/models/
0 05-21-03 20:16 billboard/textures/
710 04-05-03 13:01 billboard/models/billboard.3ds
0 05-21-03 20:16 billboard/textures/medres/
2375783 04-11-03 23:03 billboard/textures/medres/billboard.png
-------- -------
2432073 7 files
2.0: Using the Billboard.
#Hoag's Object
Nebula "Billboard" {
Mesh "billboard.3ds"
Axis [-0.235944 0.829369 0.343357]
Angle 152.350
Distance 6.0e+8
RA 15.3208 # 15h 17m 17s
Dec 21.57917 # 21deg 34' 45"
Radius 60000
InfoURL "http://heritage.stsci.edu/2002/21/fast_facts.html"
}
The name "Billboard" is just being used as an example. There is no
real nebula with that name.
In order to use this 3DS model for different objects in Celestia,
ones not called "Billboard",
you have to copy the model file, creating a new .3ds file
in a models directory.
Each copy of the model must be given a different name.
You also have to edit the new 3DS file to change the name of the
texture image file that it looks for. Currently it specifies
billboard.png. You cannot use most text editors to make this change
because of the binary codes in the model file. A binary editor like
HexEdit can be used, but I found that Emacs works quite well.
The image filename in the 3DS model file is a null-terminated string.
When using Emacs, I found that I could use any length filename I
wanted. If you use this object only with Celestia, the texture name
doesn't have to be exactly the same length as in the original file.
Apparently, however, most 3D programs can't decode this model unless the
name is precisely 8.3 characters. Note that "billboard.png" is 9.3.
You don't have to specify a PNG image file, of course. Celestia will
happily render a .JPG or .DDS file just as well. However, the image
file does need to be in a directory named textures/medres.
For example, if you wanted to display an image of a portion of the Eta Carina
nebula, do the following:
- Acquire a picture of the Carina Nebula.
- Using your favorite picture editor, create a new version of the picture
that is square and a power of two on a side. For example, create
a picture that is 1024x1024.
- Save your new picture of the Carina Nebula in your directory
textures/medres as carina.jpg
- Create a DSC file named
carina.dsc in your
extras directory, containing the following Nebula definition:
carina.dsc:
# Eta Carina Nebula (detail)
#
# the "billboard" picture used with this definition is derived from
# a NASA/STScI image found on the Web (see below)
#
Nebula "Carina" {
Mesh "carina.3ds"
Axis [ 0.517248 -0.0448043 0.854662 ]
Angle 149.296
Distance 8000
RA 10.7454 # 10h 44m 46s
Dec -59.6487 #-59deg 38' 56"
Radius 4.55
InfoURL "http://hubblesite.org/newscenter/archive/2000/06/fastfacts"
}
- Copy the file
billboard.3ds to carina.3ds in your
models directory.
- Using your favorite binary file editor, change the filename inside
carina.3ds from billboard.png to
carina.jpg
- Start Celestia and
GoTo Carina
- Enjoy the sight!
Bear in mind that this .DSC file provides the coordinates of a tiny
portion of the Carina Nebula, corresponding to the picture taken by the Hubble
telescope. You'll have to use different coordinates if you use a
different picture. See below for the coordinates
used for a picture of the whole nebula.
Note:
If you use both Carina Nebula definitions, combine both .DSC files into
one. Make sure that NGC 3372 is defined first, before Carina. That will ensure
that the larger image is drawn first, behind the smaller one.
3.0: Problems with the Flat Billboard.
- This billboard model file cannot be read by 3D modelling programs unless the
filename is 8.3 characters: 8 letters in the name of the file, 3
letters in the filetype, with a dot between them.
- A problem in Celestia v1.3.0 is that 3DS Nebula models are not
depth sorted. Instead, they are drawn on your screen in the order that
you define them or in the order that Celestia happens to read
their .DSC files.
If overlapping 3DS Nebula models are declared in separate files.
often they are drawn in the wrong order. When they overlap,
you may not be able to see the one that is supposed to be closest to you.
However, when you declare them in the same .DSC file, the model that is declared
first in that .DSC file is drawn first, the second one is drawn on
top of the first one, etc. At least that way you have some control over
which ones are visible from a particular viewpoint.
- When you GoTo a Billboard object, Celestia often overshoots.
I suspect the extreme aspect ratio (100x100x1) may be confusing it.
If it thinks you are inside the object, various parts of the billboard
get clipped off. In some cases, the whole thing will be invisible.
Typing a "C" (center) or "T" (track) command and then backing away from it
usually makes the billboard visible again.
- In the past, another difficulty for me has been getting the correct
values for the Axis and Angle directives so the billboard is properly oriented and face-on
to the line-of-sight from Earth. A recent insight made it much easier,
though. The details are a little too complicated
to go into right here. See
6.0: Aligning Pictures and Objects below.
4.0: Some Background.
The 3DS model that I've created for use as a billboard is a
flattened cube, 100x100x1 units
on a side. The Z dimension is minimized to eliminate the X and Y faces.
The Z faces are the ones where Celestia draws the surface texture.
Only the pixels at the edges of the texture image are
drawn on the X and Y faces.
The actual size the billboard object doesn't matter, only its proportions.
Celestia scales it to match the radius you specify in the .DSC file.
The 3DS model could just as well have been 1000x1000x10.
When seen from the front, the image on the positive Z face
is upright. The image is reversed on the back of the billboard object.
As a result, the picture seems to be embedded inside the billboard. The
billboard object is thin enough that it's effectively invisible when
seen from the sides.
The example surface texture file billboard.png that I've supplied
happens to be an image of Hoag's Object. The image that Celestia
renders is somewhat fainter than it should be. The greyscale alpha channel is
transparent where there should be dark obscuring dust clouds, since the
conversion software cannot distinguish between darkness due to
obscuration and darkness due to the lack of stars.
Producing a proper alpha channel for Hoag's Object
is left as an exercise for the artist. If someone does produce a good
transparency channel, I'll be glad to include it here.
5.0: Some Examples.
Below are pictures of the billboard in use.
Each of the pictures is a link to much larger image.
5.1: Hoag's Object
- billboard.3ds (1KB)
This is the 100x100x1 "billboard" mesh described
above. Its texture has
not been changed. It specifies the texture map
billboard.png. Rename an appropriate PNG image or edit
this mesh file to use a different picture.
billboard.dsc
#Hoag's Object
Nebula "Billboard" {
Mesh "billboard.3ds"
Axis [-0.293399 0.89844 0.326684 ]
Angle 165.499
Distance 6.0e+8
RA 15.3208 # 15h 17m 17s
Dec 21.57917 # 21deg 34' 45"
Radius 60000
InfoURL "http://heritage.stsci.edu/2002/21/table.html"
}
After you've installed these, your directory structure should look something like this:
[-] Celestia130
--- data
[-] extras
| [-] addons
| [-] billboard
| -- billboard.dsc
| --- models
| -- billboard.3ds
| [-] textures
| --- medres
| -- billboard.png
--- models
[+] textures
For an explanation of why your directories should be organized like
this, please see
- A (not so) Brief Introduction to Add-Ons (2nd edition)
5.2: Eta Carina Nebula (detail)
|
Image
|
Comments
|
![[Earth in the Carina Nebula]](carina-earth.jpeg)
Earth in the Carina Nebula
|
This image was not generated by cheating, as a previous version was.
To see this and similar dramatic views, one only has to find the
right combination of viewpoint and telescopic magnification.
Aye, there's the rub.
Unfortunately, adjusting Celestia's viewpoint is extremely
difficult at high magnifications.
This image was finally acquired by first aligning the Earth's orbit
and then letting the planet drift across the field of view.
Cel:// URLs for Earth and the Nebula
Each is progressively closer to the detailed Hubble picture.
This looks best if you also install the definition below for NGC 3372.
|
![[Carina Nebula Detail]](carina-2k.jpeg)
Carina Nebula Detail
|
This texture map was derived from a Hubble image showing details
of a portion of the nebula.
See the acknowledgements below.
The DXT3 file includes an alpha channel to trim off the black borders.
|
- carina.3ds (1KB)
This is the same 100x100x1 "billboard" mesh described
above. Only its texture has
been changed. It specifies the texture map
carina.jpg. Rename an appropriate JPEG image or edit
this mesh file to use a different picture.
carina.dsc (1KB, updated 21May2003
with a more accurate orientation for the detailed picture)
# Eta Carina Nebula (detail)
#
# the "billboard" picture used with this definition is derived from
# a NASA/STScI image found on the Web (see below)
#
Nebula "Carina" {
Mesh "carina.3ds"
Axis [ 0.517248 -0.0448043 0.854662 ]
Angle 149.296
Distance 8000
RA 10.7454 # 10h 44m 46s
Dec -59.6487 #-59deg 38' 56"
Radius 4.55
InfoURL "http://hubblesite.org/newscenter/archive/2000/06/fastfacts"
}
After you've installed these, your directory structure should look something like this:
[-] Celestia130
--- data
[-] extras
| [-] addons
| [+] billboard
| [-] Carina
| -- carina.dsc
| --- models
| -- carina.3ds
| [-] textures
| --- medres
| -- carina.jpg
--- models
[+] textures
For an explanation of why your directories should be organized like
this, please see
- A (not so) Brief Introduction to Add-Ons (2nd edition)
5.3: Eta Carina Nebula: NGC 3372
|
Image
|
Comments
|
![[Earth in NGC 3372]](ngc3372-view.jpeg)
Earth in NGC 3372
|
Cel:// URL for this viewpoint:
|
![[NGC3372]](ngc3372-1k.jpeg)
NGC 3372
|
This texture was derived from the image
02192.tiff.
Credit: NOAO/AURA/NSF.
For details, see the
acknowledgements below.
The dds texture includes an Alpha channel to trim off the black borders.
|
-
ngc3372.3ds (1KB)
This is the same 100x100x1 "billboard" mesh described
above. Only its texture has
been changed. It specifies the texture map
ngc3372.jpg. Rename an appropriate JPEG image or edit
this mesh file to use a different picture.
- ngc3372.dsc (1KB, updated 21May2003
with a more accurate orientation for NGC 3372)
# NGC 3372
#
# The accompanying images of NGC3372 were derived from 02192.TIFF
# at http://www.noao.edu/image_gallery/html/im0061.html
# Original tiff image credit:
# "National Optical Astronomy Observatory/
# Association of Universities for Research in Astronomy/
# National Science Foundation"
#
# According to http://www.noao.edu/image_gallery/copyright.html
# their images may be used freely for
# educational outreach activities composed by amateur astronomers.
#
Nebula "NGC 3372" {
Mesh "ngc3372.3ds"
Axis [-0.206916 0.153726 0.966206]
Angle 154.5
Distance 8500
RA 10.7345
Dec -59.752
Radius 219
InfoURL "http://www.noao.edu/image_gallery/html/im0061.html"
}
After you've installed these, your directory structure should look something like this:
[-] Celestia130
--- data
[-] extras
| [-] addons
| [+] billboard
| [+] Carina
| [-] NGC3372
| -- ngc3372.dsc
| --- models
| -- ngc3372.3ds
| [-] textures
| --- medres
| -- ngc3372.jpg
--- models
[+] textures
For an explanation of why your directories should be organized like
this, please see
- A (not so) Brief Introduction to Add-Ons (2nd edition)
Note:
If you use both Carina Nebula definitions, combine both .DSC files into
one. Make sure that NGC 3372 is defined first, before Carina. That will ensure
that the larger image is drawn first, behind the smaller one.
- carina.zip (4MB, 21May2003)
The file carina.dsc in this zip archive includes the
declarations for both NGC 3372 and the detailed Hubble picture of
Carina.
Archive: carina.zip
Length Date Time Name
-------- ---- ---- ----
0 05-21-03 22:24 carina/
0 05-21-03 22:24 carina/models/
711 04-13-03 19:27 carina/models/carina.3ds
712 05-21-03 22:29 carina/models/ngc3372.3ds
0 05-21-03 22:24 carina/textures/
0 05-21-03 22:24 carina/textures/medres/
5592560 04-13-03 19:28 carina/textures/medres/carina-2k.dds
5592560 04-13-03 15:00 carina/textures/medres/ngc3372-2k.dds
1315 05-21-03 22:15 carina/carina.dsc
-------- -------
11187858 9 files
5.4: Horsehead Nebula Region
|
Image
|
Comments
|
![[Seeing Barnard 33 past Pan]](b33pan.jpeg)
Seeing Barnard 33 past Pan
|
Cel:// URLs for Pan and the Nebula:
Barnard 33 is also known as the Horsehead Nebula.
The following are points-of-view to help align the other nebulae in Orion.
|
![[Horsehead Region]](horsehead_region-1k.jpeg)
Horsehead Region
|
These textures were derived from an
astrophotograph taken by
Walter Koprolin. They are provided here
with his kind permission for use with Celestia. For details, see the
acknowledgements below.
These DDS files are in DXT1c format. They do not contain an Alpha
channel.
|
- b33.3ds (1KB)
This is the same 100x100x1 "billboard" mesh described
above. Only its texture has
been changed. It specifies the texture map
b33.jpg. Rename an appropriate JPEG image or edit
this mesh file to use a different picture.
- b33.dsc (1KB; updated 22May03 to improve its
orientation.)
#Horsehead Nebula in Orion
#
# the "billboard" picture used with this definition is derived from
#a photograph of the Horsehead Nebula Region taken by Walter Koprolin,
# Austria, Europe: http://www.astro.univie.ac.at/~koprolin/
#
Nebula "Barnard 33" {
Mesh "b33.3ds"
Axis [ -0.641856 0.38352 -0.664029 ]
Angle 132.636
Distance 1600
RA 5.69
Dec -2.35
Radius 40.3
}
After you've installed these, your directory structure should look something like this:
[-] Celestia130
--- data
[-] extras
| [-] addons
| [+] billboard
| [+] Carina
| [+] NGC3372
| [-] B33
| -- b33.dsc
| --- models
| -- b33.3ds
| [-] textures
| --- medres
| -- b33.jpg
--- models
[+] textures
For an explanation of why your directories should be organized like
this, please see
- A (not so) Brief Introduction to Add-Ons (2nd edition)
5.5: Some Planetary Nebulae.
pn.zip (300KB, update: 25May03)
This ZIP archive contains pn.dsc and four billboard models and their
associated pictures. They provide the planetary nebulae images shown
above. It was updated on May 25th to precisely align the images of the
nebulae.
After you've installed this archive, your directory structure should look something like this:
[-] Celestia130
--- data
[-] extras
| [-] addons
| [+] billboard
| [+] Carina
| [+] NGC3372
| [+] B33
| [-] pn
| -- pn-readme.txt
| -- pn.dsc
| --- models
| -- ngc2346.3ds
| -- ngc2392.3ds
| -- ngc2440.3ds
| -- ngc6369.3ds
| [-] textures
| --- medres
| -- ngc2346.jpg
| -- ngc2392.jpg
| -- ngc2440.jpg
| -- ngc6369.jpg
--- models
[+] textures
For an explanation of why your directories should be organized like
this, please see
A (not so) Brief Introduction to Add-Ons (2nd edition)
6.0: Aligning Pictures and Objects.
One way to get the orientation and position correct for a remote
astronomical object being represented by a Nebula
is to properly orient a
photograph and then match your model to the picture.
These adjustments are needed because the accepted astronomical coordinates
of an object usually are nowhere near the centroid either of its photograph
or of the model that you've designed.
In summary:
- Place a photograph of the nebula, including the surrounding stars,
within Celestia.
- Observe the photograph from a viewpoint near the Earth
- Align the picture face-on to the viewpoint.
- Adjust your object's position to match the starry background
- Repeat steps 3 and 4 as necessary.
In detail:
-
Place a photograph of the nebula, including the surrounding stars,
within Celestia.
My "Billboard" object can be used for this, or you can
construct one of your own. See
above.
-
Observe the photograph from a viewpoint near the Earth
Use a telescopic viewpoint from the vicinity of the Solar System to look at
your picture.
E.g.: Goto Earth, Track object, increase magnification with the "," command
until the object fills your field of view appropriately.
-
Align the picture face-on to the viewpoint.
You'll need to set the Axis and Angle of the picture's DSC definition so
the image is face-on to
the solar viewpoint and rotated into the correct position against the
background stars. You can use Celestia's builtin positioning tool to
determine these values:
- Run Celestia so it creates a log file:
.\celestia -v > align.log
- Type the key pair "
Shift-~" to enable edit mode
- Hold down
Control-Shift Left-Mouse-Button and use the mouse
to adjust the object's x-y orientation.
- Hold down
Control-Shift Right-Mouse-Button and use the mouse
to adjust the object's Z-axis rotation orientation.
- Type the key pair "
Shift-!" to save your final Axis and Angle values to
align.log
- Exit Celestia
- Type
align.log
- Put the Axis and Angle values you see there into your object's .DSC
file.
If these instructions are too cryptic, please take a look at
the 6.2: Axis and Angle adjustment details
below.
-
Adjust your object's position to match the starry background
Edit the object's DSC file. Restart Celestia after each edit.
Change the RA, Dec and Radius
values until the stars of the photograph precisely match those which
Celestia draws in that region. There's no reason to adjust the distance.
That's the least
well known of any of the parameters. Once the distance has been set to
a reasonable value, changing the radius of the object is all that's
needed to make the object's size appropriate.
You have to exit and restart Celestia each time you modify the
DSC file. I usually use a Cel://URL to restart Celestia with the appropriate
viewpoint, with the object selected and centered.
- Repeat steps 3 and 4 as necessary.
Sometimes moving the object will change its location enough that it no
longer directly faces the solar system. This makes it harder to line up
with the stars around it. Realigning the object's Z axis may help.
Sometimes there simply aren't enough stars in Celestia near the
object you're trying to align.
In some cases I've had to install Pascal's 2 million star
database in order to have enough stars nearby. This extended database
is available at
http://perso.wanadoo.fr/celestia.stars/index.html.
Another way to get enough alignment stars is to use a larger picture of
the area which includes many stars. Some are sure to overlap Celestia's
stars. Align the larger picture to Celestia's stars, then align
the smaller picture on the larger one. This is easiest if you use a
translucent image: a PNG or DDS image with an alpha channel.
I've found that using an alpha channel that's a greyscale version of the
image being aligned works quite weil. The stars are white, so they're
opaque, while the darker spaces between the stars become more or
less transparent.
As a result, it's easy to see the stars of the background picture
through the picture being aligned.
When working with more than one picture billboard, put the ones that cover
a larger area first in the DSC file. Pictures that cover a smaller area
should be later in the same DSC file. This ensures that larger
pictures are drawn before smaller ones. The ones
drawn last will seem to be in front of the earlier ones.
This is necessary because Celestia does not yet depth-sort Nebula
objects. If it did, you could just declare them at appropriate
distances and the order wouldn't matter.
Once you've managed to get your photograph(s) oriented correctly,
add your 3D model as the final object in that same DSC file.
This makes Celesia draw your Nebula model last, in front of the pictures.
Then use the same procedures as above to change the model's orientation and
position (Axis, Angle, RA, Dec and Radius) until it precisely matches
the photograph.
Finally, you can comment out the DSC entry for the photograph and your
model will be shown at the right location in space.
Although mouse movements can be used to adjust an object's orientation,
trying to align the object to properly face the earth can be quite
frustrating. Not only does the object often rotate in quite unexpected
directions, but finding exactly the right direction for the object to
face sometimes can be difficult.
If you've created your models similarly to the way I created the
Billboard, then the Z face is the one you want facing toward the Solar
System. Celestia's rotational adjustment assumes this is the case.
To orient your object properly, you need to point the normal vector
of the positive Z surface toward the viewpoint.
Although this jargon sounds complicated,
thinking about it in these terms can be used to simplify how one does the
alignment. Below is a solution that I came up with after thinking
about it this way.
Briefly, you should align a long, skinny object instead of the
relatively flat or round object that you've designed.
It will be properly aligned when you've
positioned the the object's Marker in the center of the relatively small
front (Z) surface of that long, skinny object
while you're looking at it from the solar system. The
resulting Axis and Angle values can then be used to properly orient
the real object.
The alignz.zip archive below contains a 3DS model of a long,
skinny box which has a small Z surface covered by an alignment pattern.
You can follow the following steps to simplify positioning of your object:
- Modify the file
alignz.dsc
to contain the desired position of the object you're creating for
Celestia.
- Run Celestia so it creates a log file:
.\celestia -v > align.log
In other words:
- Open a command window (sometimes misnamed a DOS window)
cd to the directory where you put Celestia
- type the command
.\celestia -v > align.log
.\celestia
means "run the program in this directory that's named celestia"
-v
means "create a log of debugging messages"
>
means "send the log output to the file name which follows"
align.log
is the name of the log file that you want Celestia to create.
You can use any file name you want. I chose "align.log"
- Enable Markers with the
Control-K command.
- Select
alignz and view it telescopically
from the solar system
-
Use Celestia's builtin alignment controls to center
alignz's Marker on its alignment grid.
- Type the key pair "
Shift-~" to enable edit mode
- Hold down
Control-Shift Left-Mouse-Button and use the mouse
to adjust the object's x-y orientation until the Marker is centered on
the grid.
- Hold down
Control-Shift Right-Mouse-Button and use the mouse
to adjust the object's rotation orientation until the object is
correctly aligned with the Celestial coordinate system. (Requires
Celestia v1.3.1pre3 or later.)
- Type the key pair "
Shift-!" to save your final Axis and Angle values to
align.log
- Exit Celestia
- Type
align.log
- Put the Axis and Angle values you see there into your object's .DSC
file.
7.0: Some 3D Billboards.
7.1: A Pie-Plate Galaxy.
7.2: A Sphere to map the Sky.
This add-on requires Celestia v1.3.1 prerelease 3 or later. It doesn't
work with earlier versions of the program. In particular, it does not
work with v1.3.0. Sorry.
Here is a sphere with its surface normal vectors reversed, which
can be used to as a screen on which to project maps of the sky.
It's like having a planetarium within Celestia.
3D display systems only draw
surfaces if their surface normal vectors point toward the observer.
Usually a sphere's surface normals point
outward, so 3D display programs seem to draw an image of the outside of the
sphere. With the normals reversed, you see the inside of the sphere
instead. The side closest to you, which normally would be opaque, is
now transparent because its normals are pointed away from you. The far
side of the interior, which normally would not be drawn, both because
it would have been hidden by the front surface and because its normals
point away from you, is now visible.
Here's an example showing a map of galactic Infrared emissions
against the Milky Way.
These files were updated on 16Jun03 to properly orient the model of the
sphere and with a regenerateed map which corresponds with the corrected orientaion.
- mw-msx.3ds (26K, updated 16Jun03)
(this is a sphere which specifies the surface texture
mw-msx-2k.png)
- mw-msx.zip (350KB, updated 16Jun03)
Archive: mw-msx.zip
Length Date Time Name
-------- ---- ---- ----
0 06-14-03 17:15 mw-msx/
907 06-14-03 17:19 mw-msx/mw-msx.html
1978 06-16-03 20:05 mw-msx/mw-msx-readme.txt
0 06-14-03 17:15 mw-msx/models/
26103 06-16-03 19:28 mw-msx/models/mw-msx.3ds
0 06-14-03 17:15 mw-msx/textures/
0 06-14-03 17:15 mw-msx/textures/medres/
359778 06-16-03 19:46 mw-msx/textures/medres/mw-msx-2k.png
873 06-16-03 19:49 mw-msx/mw-msx.dsc
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389639 9 files
Here's the contents of mw-msx.dsc:
Nebula "mw-msx" {
Mesh "mw-msx.3ds"
Axis [-0.409897 0.623875 0.665406]
Angle 217.369
RA 17.76033
Dec -28.936172
Distance 2
Radius 10000
InfoURL "http://irsa.ipac.caltech.edu/applications/MSX/galplane.html"
}
These Axis, Angle and position values precisely align the sphere with
the galactic plane. The center of the sphere is slightly offset from the solar system in order
to avoid numeric problems. 2 LY out of 10,000 isn't noticable at all.
8.0: Acknowledgements.
- The billboard objects were created by Selden Ball using
Anim8or.
Anim8or was written by
Steve Glanville.
- The "Hoag's Object", "Carina" and "NGC 4622" images used
with the billboards above
were derived from pictures published on the Web at
http://hubblesite.org/newscenter/archive/2000/06/
(Carina Nebula),
http://heritage.stsci.edu/2002/21/table.html
(Hoag's Object), and
http://hubblesite.org/newscenter/archive/2002/03/image/a
(NGC 4622).
Credit for the
original images goes to
NASA and the
Hubble Heritage Team
(
AURA
/
STScI).
- The texture for NGC 3372 was derived from
the image 02192.TIFF, available at
http://www.noao.edu/image_gallery/html/im0061.html.
The credit for this picture goes to "National Optical Astronomy Observatory/
Association of Universities for Research in Astronomy/
National Science Foundation."
According to the NOAO copyright page at
http://www.noao.edu/image_gallery/copyright.html,
their images may be used freely for
"educational outreach activities composed by amateur astronomers".
That's what this is.
- The image of the Horsehead Nebula Region was taken by Walter Koprolin,
Austria,
Europe:
http://www.astro.univie.ac.at/~koprolin/.
For exposure data, a short description and some observing hints for
this object, see his
Horsehead's page at
http://www.astro.univie.ac.at/~koprolin/Photo/Neb/Horsehead_Region.html
-
Credit for the
original Planetary Nebulae images goes to
NASA and the
Hubble Heritage Team
(
AURA
/
STScI).
-
The
mw-msx map was taken from an MSX (Midcourse Space Experiment) mosaic
which can be seen on the Web at
http://irsa.ipac.caltech.edu/applications/MSX/galplane.html.
Creation of the mw-msx map made use of data products from the Midcourse
Space Experiment. Their processing of the data was funded by the
Ballistic Missile Defense Organization with additional support from
NASA Office of Space Science.
This creation has also made use of the NASA/ IPAC Infrared Science
Archive,
which is operated by the Jet Propulsion Laboratory, California
Institute of Technology,
under contract with the National Aeronautics and Space Administration.
Contents
[back to Contents]
A.0 Appendices.
![[billboard image]](billboard.jpg)
![[billboard texture]](billboard.png)
![[Earth in the Carina Nebula]](carina-earth.jpg)
![[Carina Nebula Detail]](carina-2k.jpg)
![[Earth in NGC 3372]](ngc3372-view.jpg)
![[NGC3372]](ngc3372-1k.jpg)
![[Seeing Barnard 33 past Pan]](b33pan.jpg)
![[Horsehead Region]](horsehead_region-1k.jpg)
![[ 4 planetary nebulae ]](pn4.jpg)
![[ngc 4622]](ngc4622.jpg)
![[ngc 4622 closeup]](ngc4622-visit.jpg)
![[ngc 4622 #4]](ngc4622-4.jpg)
![[MSX IR Mosaic]](mw-msx-02.jpg)
![[The fire this time: MSX IR map of the Milky Way]](mw-msx.jpg)
![[MSX IR Mosaic map]](mw-msx-2k.png)
