Some questions

The place to discuss creating, porting and modifying Celestia's source code.
Avatar
Topic author
parduz
Posts: 26
Joined: 21.04.2003
With us: 21 years 6 months
Location: Bologna (Italy)

Some questions

Post #1by parduz » 21.04.2003, 00:27

I have some questions i can't figure out myself, sorry to bore you all:

1) What's about Orientation and RotationOffset value? How can i use it to place a ship flying 1Km high on the surface (at equator) and another ship just some meters back from the first?

2) How to add a xyz for that ships? Is XYZ files able to change the rotation of an object (think at a plane, when it turn 90°)?

3)What happens at the end of a XYZ file? ogject continue in the last given direction, or restart from the beginning?

4) I'm trying to "build" the Rebels attack to the DeathStar, showing X-Wings flying inside the "valley" of the DeathStar, followed by the Tie-Fighters. Do you know a place that can host my final work, or someone that can take the files and host it?

CIAO!

Avatar
selden
Developer
Posts: 10192
Joined: 04.09.2002
With us: 22 years 2 months
Location: NY, USA

Post #2by selden » 22.04.2003, 12:20

parduz,

Have you figured this out yet? Essentially, you got things reversed.

Orientation and RoatationOffset control where the spacecraft point. Use them to solve your question #2

XYZ files control only where your spacecraft is located at what time. If you can calculate the right values, you can use them to solve your question #1.

When Celestia advances time past the last position in an xyz file, the object just stays at that last position.

If you don't use xyz files, the result will be quite small. You can just post your SSC files here and include links to the sites where you got your models.
Selden

Guest

Post #3by Guest » 22.04.2003, 18:45

selden wrote:Orientation and RotationOffset control where the spacecraft point. Use them to solve your question #2

Ok, but how to use them? what means a Orientation [90 1 0 0] ?

selden wrote:XYZ files control only where your spacecraft is located at what time. If you can calculate the right values, you can use them to solve your question #1.
Again, i'm a bit in difficult. I've tried some Julian calendar converters, but numbers are not what i see on some XYZ files, so i'm lost in the space/time continuum :D

selden wrote:If you don't use xyz files, the result will be quite small. You can just post your SSC files here and include links to the sites where you got your models.
That's the problem, i don't have a site right now, so i'm asking for some good free server

Thanks

chris
Site Admin
Posts: 4211
Joined: 28.01.2002
With us: 22 years 9 months
Location: Seattle, Washington, USA

Post #4by chris » 22.04.2003, 19:17

Parduz wrote:
selden wrote:Orientation and RotationOffset control where the spacecraft point. Use them to solve your question #2

Ok, but how to use them? what means a Orientation [90 1 0 0] ?
The first number is an angle in degrees, and the last three numbers are an axis. So Orientation [90 1 0 0] means rotate 90 degrees about the x axis. Many people have complained about this, so I'm planning to add the option to specify a list of three numbers which are rotations about the x, y, and z axes.

selden wrote:XYZ files control only where your spacecraft is located at what time. If you can calculate the right values, you can use them to solve your question #1.
Again, i'm a bit in difficult. I've tried some Julian calendar converters, but numbers are not what i see on some XYZ files, so i'm lost in the space/time continuum :D
The first number on each line is just a plain old Julian day numbers . . . The other three numbers are the position in units of kilometers.

Parduz wrote:
selden wrote:If you don't use xyz files, the result will be quite small. You can just post your SSC files here and include links to the sites where you got your models.
That's the problem, i don't have a site right now, so i'm asking for some good free server

SSC files are usually small enough that you can just cut and paste the contents directly into a forum post--no need for web space of your own.

--Chris


Return to “Development”