How to position objects lower down by default

[DiscoveryDome]

Hi everyone

I'm using Celestia in a mobile planetarium, and as you can imagine, the centre of the computer screen for you is the zenith (top) of the dome for me ie. when a planet appears, it is positioned by default at the very top of the dome for me (and at the centre of the computer screen for you).

Is there a way perhaps to change the default settings in Celestia to have objects positioned lower down on the screen? ie. for me that would mean lower down at the front of the dome, allowing my audience to enjoy the view without hurting their necks?

Your help would be greatly appreciated (not only by me, but by the growing digital planetarium community using Celestia too)!

Thank you in advance

Mario

[Chuft-Captain]

Welcome Mario,

The following procedure does not change the default behaviour, but will allow you to reposition objects with the press of a key.

1. Create a file with your favorite text editor (wordpad will do).
2. Paste the following text into it:

Code: Select all

-- Title: Move object lower (for Planetarium use)
-- ... Beginning of script

rad = -0.1
steps = 30
xOn   =celestia:newvector(1,0,0)
yOn   =celestia:newvector(0,1,0)
zOn   =celestia:newvector(0,0,1)
rOn   =xOn

      obs   = celestia:getobserver()

         angle= math.asin(rad)                     -- in [-pi/2;pi/2]
         -- calc step-quaternion
         quat=celestia:newrotation(xOn, angle/steps)
         for i=1,steps do
             obs:rotate(quat)
             wait(0)
         end--for


-- End of script...


3. Save it with the name "down.celx" to your C:\Program Files\Celestia\scripts folder.

4. In the C:\Program Files\Celestia folder, you will find a file called celestia.cfg. Open this with your editor and change:

Code: Select all

DemoScript  "demo.cel"


to:

Code: Select all

#DemoScript  "demo.cel"
DemoScript  "C:/Program Files/Celestia/scripts/down.celx"

Now, each time you press the "D" (demo) key, the script will rotate the viewpoint to bring your objects down from the zenith by a specified amount. (ie. closer to the bottom edge of the screen.)
You can adjust the amount of movement to your specific requirements by adjusting the value of the "rad" variable.

NOTE: This redefines the "D" key to run this script instead of the demo script, so you will no longer be able to run the default Celestia demo.
If this is important to you, then skip step 4, and run the script from the script menu instead.

Hope this is helpful
CC

[DiscoveryDome]

Thank you very much for this, I will attempt to implement it soon. I hope to use your code to reposition each planet as it appears. Thanks again.

[DiscoveryDome]

Problem.

I've just tried to add this suggested script (or elements of it) into the Demo script (to cause the planets to appear lower down on the screen by default), and unfortunately failed.

You see, I need the "D" key to run the demo, so I would rather add a few lines of code to the Demo script (or other scripts) to make this adjustment happen automatically.

Is it possible to do so?

Oh yes, and I'm using version 1.4.1.

Thanks very much!


Mario

[Adirondack]

I've just tried to add this suggested script (or elements of it) into the Demo script (to cause the planets to appear lower down on the screen by default), and unfortunately failed.

Mario,
that doesn't work! You can't add CELX code to a CEL script!

Adirondack

[John Van Vliet]

--- edit ---

[BobHegwood]

the differences from 1.4 to 1.6 is like windows 98 to vista

Please don't use that example. Very baaaaaad comparison.

[Chuft-Captain]

I've just tried to add this suggested script (or elements of it) into the Demo script (to cause the planets to appear lower down on the screen by default), and unfortunately failed.

Mario,
that doesn't work! You can't add CELX code to a CEL script!

Adirondack

Mario,
it is possible to embed a CEL script within a CELX script (the reverse of what you tried to do) , using a "celscript" command, however it is somewhat less than straightforward and probably wouldn't achieve what you want anyway.
I think your best chance is to make a CELX version of the existing demo.CEL. This also, will not be easy as you'll need to get up to speed on both CEL and CELX scripting, but this would allow you to make use of my CELX code for repositioning the viewpoint. (Although by the time you've mastered scripting well enough to do that re-write, I suspect you will have come up with a better way of doing that anyway. )

[John Van Vliet]

--- edit ---