Astrological add-on

[Slalomsk8er]

I would like to do a Astrological add-on for my love.

As I understand it, cmod is the way to do it. Can some one point me to some tutorials please?

What I plan to do:

Draw lines beginning from earth through all other planets and let them end at the zodiac disc.

Draw a zodiac disc / ring a round the solarsystem.

This would look like a interstellar clock (the celestia clock)!

Thanks, Dominik

[selden]

Sorry, there are no tutorials for creating CMOD files. A crude description of the format of a CMOD file is available at http://www.lepp.cornell.edu/~seb/celestia/celestia_notes.html#14.0


However, you should be able to do the same thing using 3D modelling software that outputs 3DS format models. Celestia understands those, too.

Creating complex models sometimes can take a very long time. In some circumstances, displaying a rectangular picture on a flat or spherical model ("billboard") can be almost as good. See http://www.lepp.cornell.edu/~seb/celestia/billboard.html
The examples there are Nebula objects, but they can be used as Meshes in an SSC just as easily.

Does this help?

[Slalomsk8er]

Thanks selden, your first link is realy usefull for me.

I think the zodiac ring is not a problem for me, but I wondering how can I get lines starting from earth pass through the center of a other planet and ending on my zodiac ring?

Thanks, Dominik

[selden]

Dominik,

The lines through the planets could be done similarly to the way axis lines can be drawn. It's "only" a matter of creating appropriate SSC entries.

See http://www.lepp.cornell.edu/~seb/celestia/graticules.html#5
for an example of how to draw axis lines using a CMOD model.

[Slalomsk8er]

Thanks, for the good news.

Normaly the things I want to do are technicaly impossible

So, it's "only" a matter of creating appropriate SSC entries and a good cmod pac.

Hope that I can find the time to do it this year

Dominik

[Slalomsk8er]

Till now I found no way to let the lines start at earth and pass through the planets.
With the earth centric clock out of my reach I started to build one with the sun in the middle.

But I have some problems:

This is the line I use:

Code: Select all

#celmodel__ascii
 
# polar axis
# designed by s.ball 20nov04
 
material # northern half of line
 emissive 0 1 0      # 0 1 0 = Green
 diffuse 0 1 0
 opacity 1.0
end_material
 
material #southern half of line
 emissive 1 0 0      # 1 0 0 = Red
 diffuse 1 0 0
 opacity 1.0
end_material
 
mesh
 
vertexdesc position f3 end_vertexdesc
 
vertices 3
0  0 1  # north pole
0  0 0   # center of body
0 0 -1   # south pole
 
linelist 0 2 0 1 # northern line
linelist 1 2 1 2 # southern line
 
end_mesh

And this is on of the ssc I use:

Code: Select all

 
# this is an example usage of the Axis CMOD model
# this draws an axial line through Mars
# s.ball 20nov04
 
# use a name of " " -- just a space -- instead of something like "_MarsAxis"
#  to make the name of the Axis invisible when "planet labels" are enabled.
 
"_MercuryZeiger" "Sol" 
{
   Mesh "zeiger.cmod"
   Radius 1.5e8       #longer than Mars' equatorial radius of 3396 km
 
# duplicate the orbital and rotational orientations of the body
# that the axis should be drawn through
 
   CustomOrbit "vsop87-mercury"
 
   RotationPeriod        2109.408 # rotation in hours 12.75
   Obliquity             7.0049 # tilt angle (Inclination)
   EquatorAscendingNode    48.33167 # orientation of tilt angle
   RotationOffset       291.20
 
   Albedo            0.150
}

Code: Select all

 
# this is an example usage of the Axis CMOD model
# this draws an axial line through Mars
# s.ball 20nov04
 
# use a name of " " -- just a space -- instead of something like "_MarsAxis"
#  to make the name of the Axis invisible when "planet labels" are enabled.
 
"_VernusZeiger" "Sol" 
{
   Mesh "zeiger.cmod"
   Radius 5.5e8       #longer than Mars' equatorial radius of 3396 km
 
# duplicate the orbital and rotational orientations of the body
# that the axis should be drawn through
 
   CustomOrbit "vsop87-venus"
 
   RotationPeriod        5389.152
   Obliquity             3.3947
   EquatorAscendingNode    76.681
   RotationOffset       200.0
 
   Albedo            0.150
}

Code: Select all

 
# this is an example usage of the Axis CMOD model
# this draws an axial line through Mars
# s.ball 20nov04
 

# use a name of " " -- just a space -- instead of something like "_MarsAxis"
#  to make the name of the Axis invisible when "planet labels" are enabled.
 
"_EarthZeiger" "Sol" 
{
   Mesh "zeiger.cmod"
   Radius 5.5e8       #longer than Mars' equatorial radius of 3396 km
 
# duplicate the orbital and rotational orientations of the body
# that the axis should be drawn through
 
   CustomOrbit "vsop87-earth"
 
   RotationPeriod        8760
   Obliquity             0.0001
   EquatorAscendingNode    348.739
   RotationOffset       200.5
 
   Albedo            0.150
}

Code: Select all

 
# this is an example usage of the Axis CMOD model
# this draws an axial line through Mars
# s.ball 20nov04
 
# use a name of " " -- just a space -- instead of something like "_MarsAxis"
#  to make the name of the Axis invisible when "planet labels" are enabled.
 
"_MarsZeiger" "Sol" 
{
   Mesh "zeiger.cmod"
   Radius 8.5e8       #longer than Mars' equatorial radius of 3396 km
 
# duplicate the orbital and rotational orientations of the body
# that the axis should be drawn through
 
   CustomOrbit "vsop87-mars"
 
   RotationPeriod        16476.684
   Obliquity             1.8506
   EquatorAscendingNode    49.479
   RotationOffset       40.0
 
   Albedo            0.150
}

The big problem is: "How do I get the lines rotation center at the middle of the sun?"

Some small problems are: "In solarsys.ssc the mercury Period 0.2408 is in years but the RotationPeriod in my .ssc is in hours. But what is the definition of year and day in this context? What are the right RotationOffset values?"

At least I got the planes right