Celestia Forums

Hi,
I'm a new user; Celestia is a wonderful program with so much potenital.
I particularly like the ability to hit "copy" and save a URL of my position. I have been trying my hand at creating scripts, and I use these cel URLS in my scripts. (I'm using a Mac, so I use cel and not celx) After working with cel URLs within scripts, I have a question, or maybe a feature request
Is it possible to ease into a cel url (within a cel script), rather than abruptly appear at the position; i.e., use them as keyframes which could blend into each other, maybe at a defineable rate? I'm thinking that would make script-writing (for me at least) alot easier...
Thanks
Rich

Howdy Rich,

Welcome to Celestia!

Your question would indeed be a feature request. A cel URL, by it's nature, functions just like a hyperlink on a web page -- you click a link and are immediately taken to that place. It works the same way in scripting as it does in real-time.

May I ask what kind of script you are writing that might require "keyframing" with cel URLs?

You have probably already looked into the goto commands (goto, gotoloc, gotolonglat), right?

Hi Don,
The intention is to make the script one that kind of picks out cool things or places on earth, in earth orbit, and around the solar system. My 5 yo daughter is interested in astronomy, the script would be also for her viewing (I figure by the time I get the script(s) finished, she'll be older with the attn span for watching 'em
I pick out different things and/or places, like for instance a cool view of skylab (cel URL), I pause and orbit it for a few seconds & add some text (traditional scripting), and move on to another item (insert morph to next cel URL keyframe) - I do use the goto commands, but there's where it'd be nice to blend into another URL; so variables such as universal time, orientation, distance, fov, etc would all automatically be calculated from one view to the next, with a time definition- something like "goto {time 5 URL cel://... }". Then they could act as key frames in an animation, if you will. (I'm a CG artist, used to using keyframes )
I'll post the script-in-progress when it gets contiguous (I have it in many pieces now) and much less klugey.

Rich

Howdy Rich,

Thank you. Now I have a better understanding of what you are trying to do, and how your suggestion would make it easier.

Rich wrote:... I do use the goto commands, but there's where it'd be nice to blend into another URL; so variables such as universal time, orientation, distance, fov, etc would all automatically be calculated from one view to the next, with a time definition- something like "goto {time 5 URL cel://... }".

This could indeed provide a really nice effect, but would probably be a real bear to program -- making sure the camera doesn't travel *through* an object. Going from one date to another might create a rather messy display though, as stars whirl around to go forward or backward in time.

Rich wrote:(I'm a CG artist, used to using keyframes )

Cool! Have you posted any of your work to the web?

Yeah, I kinda had the feeling it'd be a bear to program... and it might be a little messy or "jittery" - I sometimes write my own settings files for Whitecap (an iTunes visualizer) and it will auto-blend between settings files really well, but certain things cannot blend, they just appear or disappear. I suspect some of that would have to happen with URL blending. You're right - going thru objects could be a problem, I didn't think of that... probably the scriptwriter would have to orient himself away from any local objects "manually" first, then zoom to another URL via blending, cross his fingers and hope there's no crashes!
Just thought I'd ask about it, tho.
Maybe a variation of this idea, from within celestia, like a "copy location only" or "copy orientation only" or some such command would be possible and easier to program, and could get nearly the same end result...

Either way, Celestia is an amazing program and it open source-ness will only make it even better over time. It'd be great to see a repository of tons of cel URLs from different users' "celestial experiences" .

I do indeed have a website with some of my stuff:
http://members.aol.com/rbucci1
...there are even a couple of (non-celestia) space images.

-Rich

Hi Rich,

With some luck, maybe one of the developers, or a new developer, will get a "wild idea" about how to make this work and do some experimenting.

Nice idea for having a cel URL repository too. Folks would just have to remember to list the add-ons that might be required for the scene to be visible. I just started a new topic for this.

Great web site Rich! Looks like you have a real good grasp of CG, that's for sure!

Cheers,

<< Nice idea for having a cel URL repository too. Folks would just have to remember to list the add-ons that might be required for the scene to be visible. I just started a new topic for this >>

Cool. It looks like it's already getting nicely populated. I'll have to cull thru mine & upload 'em.

<<Great web site Rich! Looks like you have a real good grasp of CG, that's for sure! >>
Thanks, Don. Glad you liked it.

Best,
Rich