View Full Version : In regards to rendering a new sky,stars,celestial objects.

22nd Oct 2002, 01:22
Okay, I've been trying to figure this out for some time. I have all the info I could find on the net, but they don't specify what I need (they do have good info, though). I've looked at other FM's and the LG techniques, but here's what I don't understand:

When rendering a new anything sky related, I figured height related equations (ie: where the moon is) would be by feet. But I've seen instances of celestial objects being created at, like, 50,000 feet! If I have a complete worldspace that totals 200 feet, then I put the moon at, say, 175 - there is no moon!!! I'm so confused! :confused: Also, how are celestial objects and stars relational in regards to the sky - I mean, do you have to calculate sky, then calculate moon and stars in regards to that (which makes sense) --- if so, how does one go about doing it??? Now, I'll prolly go home and fiddle with it and figure it out before I get an answer . LOL.:rolleyes:

22nd Oct 2002, 02:53
Ya lost me on that one. :eek:

Are you using one of the sky textures on the top surface of your outside air brush?

How are you "putting a moon it at 175 feet"?

I think you would want to rescale the sky texture smaller to make the moon look farther away?? But I' guess I'm not really sure what you're asking.

22nd Oct 2002, 20:14
Basically, I just need to know how to insert a celestial object. If I had a world of 200 feet height. (So the sky is at 200, and of course around me. How would I create the moon so it was right in the middle, and about 50 feet below the rendered sky.) ??

25th Oct 2002, 16:46
Well, I know nothing about Dromed, but it seems to me that you want the moon on the sky, not below it. You do not want to create the impression that the moon is moving relative to the stars if you walk along underneath the moon at ground level.

Which raises another issue. How do you keep the moon and the stars from changing direction as you move under them if the sky is only 200 ft away? I have played games where celestial objects seem to have a fixed direction regardless where you are on the map, and I had thought Thief was among them. Fixed direction is what you need in order to give the impression that they are far away.

26th Oct 2002, 01:34
The sky is fixed, as with any other game.
I think you're confusing the Sky Atmosphere and Earth Radius with the Celestial Object properties (which don't have a height attribute). I don't think the Sky Radius properties have anything at all to do with world (brush) space or height..they're simply a set of figures which can be adjusted relatively for subtle changes in the way the newsky is rendered. There are documents that deal specifically with this. (see below Newsky.txt...see also sky settings.doc)

You want to play around with the latitude and longtitude (try 45 and 180 for a moon half way up, straight in front (north))...Also, if you have an alpha celestial object you need to use the .tga not the .pcx graphics.

Sometimes, latitude and longitude angles are specified. Longitude angles stars at +x, and move
counter-clockwise to +y. Latitude angles start at the pole (directly above camera), and move down to
the horizon at 90 degrees.

(In other words longtitude: 90 = east, 180 = north, 270 = west, 0 = south. Latitude of 0 = pole, 90= horizon)

"Atmosphere radius"
The radius, in feet, of the sphere that represents the sky, with "earth" at the center.

"Earth Radius"
The radius of the "earth", in feet. In other words, the offset from center where the camera is.
The closer this number is to "Atmosphere radius", the less sky directly above is fogged. This
number should always be less than "Atmosphere radius".