Celestia Forums

Note:
All active dev, testers and regular folks are invited to read and comment what will follow. The topic is important enough to eventually determinate how will "look and fell" your favorite soft in the future. Please, participate.

*******************************************************
What is Celestia?
A 3D space simulator?
A 3D astronomical data base?
Is Celestia about education?
Is Celestia a Game?
Is Celestia adapted for all public? Professional public?
Who are we targeting at?
Is Celestia easy to use?
Is Celestia's use adapted to our target?
How do I use it?
Am I at ease using it?
What would I need to get a better experience?

That's the kind of questions we need to resolve to get a mature software. Are we able to answer those questions? Try it, pick some of this questions or write another one down and let us know about your answer. Before the very first step to build an UI we need a clear image of what we want. I'll begin:

Q: Is Celestia a game?
A: No

Who's next?

ElChristou wrote:Note: All active dev, testers and regular folks are invited to read and comment what will follow. The topic is important enough to eventually determinate how will "look and fell" your favourite soft in the future. Please, participate.

Christophe, I agree on your quest for a common thinking about our favourite software, so here my little cent.
*******************************************************

ElChristou wrote:What is Celestia?
A 3D space simulator?
A 3D astronomical data base?
Is Celestia about education?

Obviously all of these characteristics belong to Celestia, but with very different “weight”.
I mean that the scientific approach, even if blessed by all of us, sometimes is pushed to levels that are useless for the 99.9% of us (obviously this is my opinion, but I invite you to show me the practical need, except for scientists, to have e.g. the “Goofy” star at a distance of 23.2 kpc instead of 23.9-
On the contrary the educational approach is many times considered not so important, and for this taken on second line.

ElChristou wrote:Is Celestia a Game?

Absolutely not, obviously. It’s a powerful scientific approach to the Universe and its rules, and an incredibly useful way to make education on astronomy, for all the ages.
Just last Thursday I had a show for forty nine 6 years old children. It had to last about 45 minutes, but after two hours the teachers compelled the students to go back at school for lunch, despite they wished to stay there to see and listen more.
And these are facts, not chatters.

ElChristou wrote:Is Celestia adapted for all public? Professional public?

Yes and no, IMO.
I mean that many children that went to the Celestia link I give to all of them, and downloaded and tried Celestia as is offered as default, came back to me asking why they didn’t see the same things and with the same quality they had seen during my shows.
As it is now, Celestia is like a piece of “dried meat”, good to be eaten but too much tough for most of people’s teeth.
I feel that too many times we forget that most of them are not astronomically educated people, but only guys that reach our link for will or fortune or word-of-mouth advertising, and are curious to understand what Celestia is really capable to do.
IMHO most of times they don’t come back again, because the information are too much brief and not “tuned” for such a kind of people.
The professional public is surely more satisfied by Celestia as it is now, even if still many things are missing from this point of view, as noted by many people much more experienced than me on the matter.

ElChristou wrote:Who are we targeting at?

This is a good question, and I think the one developers should consider more than the others.
The target is the scientific side of astronomy?
If yes, many things should be changed, e.g. stop at all the fictional side of Celestia, no more fantastic worlds, no more Star Trek addons or what else, but only scientific data approached in a scientific way, nothing else.

ElChristou wrote:Is Celestia easy to use?

For the practical experience I gained with 5 years of weekly educational shows and conferences, during which I had the opportunity to taste the feeling for Celestia of more than 6000 students from 6 to 20 years old and at least 1000 adults, I think it could be much easier that what actually is.
Documentation is not so plain and easy to be understood to favour the approach to most of touching people.

ElChristou wrote:Is Celestia's use adapted to our target?

Sorry but this is not clear, at least for me.
What do you mean? This question is conflicting with your previous one “Who are we targeting”, I mean how can I reply to this if it’s not yet clear what is our target?
Or am I misunderstanding it?

ElChristou wrote:How do I use it?

As I told, mainly for educational purposes, but I use it for its scientific 3D capabilities, too.
E.g., while here the weather was horrible, I saw last feb 27th Moon-Venus conjunction using Celestia.

ElChristou wrote:Am I at ease using it?

Yes and no.
I’m not a scientist, so even if I can follow a good percentage of what Celestia offers, many things are out of my capabilities, both for my indolence to study them (my fault), and for the intrinsic difficulty of many of them, for the problems of reading them in another language, and many times for the poor quality of descriptions.
If I can express an opinion, I hate celx scripting for a simple reason: up to now no one gave me the logics of how it works, in a simple, plain way.
I tried to study the available documents, but for me they are like written in mandarin, i.e. unintelligible.

ElChristou wrote:What would I need to get a better experience?

Just some suggestions:
1- developers should decide what Celestia will be when adult, i.e. if the educational side will have the possibility to live together (but with the same attention level, not as the Cinderella that actually it looks like) with the scientific side, or not;
2- if the answer will be not, IMO Celestia should be forked in two, one exclusively dedicated to science, the other one to education;
3- a new default offering of Celestia package, with much higher quality textures and models, whose there actually exists a lot. This have been discussed here many times, but after a lot of chatters, mainly based on the diatribe “this is better than that one”, nothing was issued. And this even if someone offered his time and good will to prepare such a package that, with all the possible mistakes, surely would have been way better than the actual one;
4- a very good but simple explanatory text, giving with following increasing importance steps, a clear idea of what Celestia offers and can show.

I stop here, sorry for the length of the message, but I think your questions were worth the long time needed to reply.

Bye

Andrea

Celestia is a real-time 3D visualization tool optimized for astronomical applications.

It is *not* a simulator, although it can be used to display the results of simulations.
It is *not* a database, although it includes several different astronomical data sets.
It is *not* "about education" (that means different things to different people) although it can be used to educate.
It is *not* a game, although it can be used to create games.
It is *not* adapted for the public or for astronomical professionals, although both can use it.

It *has* gathered a lot of "cruft" over the years and probably could be improved by getting rid of its many inconsistencies.

My two cents...

Celestia is an exploratory educational tool.
For your average Brain-Dead user (i.e.- Me) I can think of no better way to
learn about the Solar System and all of it's planets and moons.
Also, I can certainly think of no better way to explore the Universe as a whole.

Obviously though, I would very much prefer that the fictional stuff be left
away from Celestia.

This, of course, brings up a wholly different class of users however. There
are many more Celestia users who simply use the program for entertainment.
There is nothing wrong with this, and you will note the considerable amount
of fictional downloads on the Motherlode. Too bad we don't have as many
totally realistic add-ons to go with them.

At any rate, what is wrong with satisfying both groups? Seems that Celestia
has been doing this with equal success for a very long time.

Again, just my Brain-Dead two cents worth.

ElChristou wrote:Note:
All active dev, testers and regular folks are invited to read and comment what will follow. The topic is important enough to eventually determinate how will "look and fell" your favorite soft in the future. Please, participate.

*******************************************************
What is Celestia?
A 3D space simulator?
A 3D astronomical data base?
Is Celestia about education?
Is Celestia a Game?
Is Celestia adapted for all public? Professional public?
Who are we targeting at?
Is Celestia easy to use?
Is Celestia's use adapted to our target?
How do I use it?
Am I at ease using it?
What would I need to get a better experience?

These are very, very good questions! Thanks for raising them, and especially for raising them now, before it relly moves to coding the new UI.

Okay, now I am trying to answer the questions from my point of view:
What is Celestia?
A 3D space simulator?
A 3D astronomical data base?
Is Celestia about education?

Well, I see it as kind of all of the above. For me Celestia is a scientifically based framework, that allows me to use it in different functions with different details. This is in my opinion very good, because it allows me flexibility and I don't need an extra program for every different function.
But the baseline is, that Celestia has to be scientifically accurate for it to function properly, meaning that the distance of stars should be accurate and up to date, compared to the scientific catalogues, that it should state when it only uses approximations or give the reasons behind general limit of knowledge.

Is Celestia a Game?
No, definitely not, well at least not in the interactive way that computergames are normally seen.
Can I use it to create fictional scenarios? Yes, of course, but that can already be see as a small bit of educational activity, because you have to look up what you have to do. No point, click and presto finished thing.

Is Celestia adapted for all public? Professional public?
This question is a bit too general, depends on what you want to do? Display spacecraft trajectories, calculate distances between stars, simulate eclipses between orbital bodies? Or plan a complete mission with all influence parameter?

Celestia is certainly a good graphical frontend showing to outcome of all the above. But it is not a physical simulation program, so as said depends on what you want to do.

Who are we targeting at?
That's the 100 million dollar question And probably a lot of people have different answers to that. Mine is, at people who are interested in space and astronomy and want to be able to visit things in 3D and see what the reality out there is, even if they can't yet go there themselves. So, it has to be realistic and correct what we are displaying.

Is Celestia easy to use?
Is Celestia's use adapted to our target?
Baisc functions, yes. More advanced functions and especially scripts, no.
Why, because our documentation that is delivered with Celestia sucks. Okay, that will probably (hopefully) change, if I am not running out of steam and some others join me in the effort.
And it definitly is missing "officially" high resolution packages of all the textures. And don't come to me with things like you can take a look at the Motherlode or Fridgers tool for creating really good textures for yourself. That is not what people want, when they get a new software and the motherlode is too confusing for a newbie. And in these days, what is preventing us from making a basic software package with a size of 100 MB or more?

How do I use it?
For my own private fun and exploration of our universe, more understanding of physics and creation of fictional systems.

Am I at ease using it?
What would I need to get a better experience?
Mostly yes, but it could definitely be better. A few points:
- Being able to change things in an DSC, STC, SSC and then just reload that part without having to start Celestia again.
- Being able to load/unload addons from within a running Celestia
- To have good descriptions of what a script does displayed from within Celestia, before starting it.
- To have good descriptions of what is within an addon displayed from within Celestia, before activating it.

Pfffeww, the list got longer than I thought, but I hope my opinion helps.

Regards,

Guckytos

selden wrote:...It *has* gathered a lot of "cruft" over the years and probably could be improved by getting rid of its many inconsistencies.

Despite I think I understand what you mean here, I find not definition of "cruft"!
Can you dev a bit what in your opinion are these "many inconsistencies"?

BobHegwood wrote:...I can think of no better way to
learn about the Solar System and all of it's planets and moons.

Do you mean that in this optic, Celestia is just perfect? You have find enough informations within Celestia and your are happy with it OR Celestia shows you stuff you didn't knew and you dig them outside Celestia? (forum, specialized sites, encyclopedias, etc...)

We have Tx to Guckytos a first idea of our eventual target: "people who are interested in space and astronomy and want to be able to visit things in 3D"

That represent a very large range of people/needs/habits.

What we can do immediately is cutting this in two, hobbyists and professionals. No problem with the Pro, they are easy to spot. The Hobbyist will be all people who's professional field is not linked to astronomy, astrophysics, space exploration and so on. Eventually we could do a subgroup of them with educators vs the others. But for now let's try to work with these two basic groups.

Can we try to do a bit of thinking to understand the differences between these 2 groups?

I start:

A Professional need efficiency. A professional need to see what he is looking for quickly without losing time. The logic in the steps to go from an idea to a visual result must be crystal clear. For the Pro (shorter!), considerations about design or estheticism is the last of the preoccupation. The Pro do have already some habits. If he can find the same feel and touch than other software he is used too this is great. The pro of course have needs linked to his particular field, but this point cannot be discussed without the Pro himself.
What else?

The Hobbyist need to dream. The Hobb (shorter!) need possibilities. The Hobb is curious, want to discover and to learn. The Hobb need a smooth experience, the steps to navigate throw this possibilities should be logical and not too complex (don't forget the Hobb can be aged from 7 to 77!). Design or estheticism can be used to improve the global experience. The Hobb can lose track and lost himself in whatever corner of the frame we are proposing, that's not a problem.
More?

ElChristou wrote:

selden wrote:...It *has* gathered a lot of "cruft" over the years and probably could be improved by getting rid of its many inconsistencies.

Despite I think I understand what you mean here, I find not definition of "cruft"! ...

Christophe, I found it here:
http://en.wikipedia.org/wiki/Cruft
"cruft" definition is:

"Computing jargon for "code, data, or software of poor quality".[1] The term may also refer to debris that accumulates on computer equipment. ("When the steel ball on the mouse had picked up enough cruft to be unreliable, the mouse was doused in cleaner.")[2] It has been generalized to mean any accumulation of obsolete, redundant, irrelevant, or unnecessary information, especially code."

Bye

Andrea

Tx Andrea. Now, let's try to stay on tracks; Some people out there haven't say anything yet. Please enter the dance and let us heard your voice!

I wrote something then accidentally lost it by closing the wrong tab. For the "what is Celestia" question, I would say an astronomical visualisation tool rather than a simulator or a database.

Most of what I had to say was in the "ease of use" category, so here's a summary of a few things I have to point out about this. I'm mainly coming at this from a content creator's perspective, since without content to visualise there is no point in having the visualiser.

• Documentation is fragmented and spread across various sites on the internet. The WikiBook is a good start, but it needs a lot more detail.
• Inconsistencies between conventions in various data files. Having RA using different units in .dsc and .stc files is ridiculous. Having the SemiAxes property use a convention where the y-axis is the rotation axis in .stc files and the z-axis in .ssc files is ridiculous.
• Inconsistent support between various data files. .stc files need support for reference frames in orbits, as the ecliptic frame never seems to be used in actual publications of binary star orbits.
• Mesh centring. If you're using .ssc files you at least have the option of using, er, what was it again, I'm sure there was mentioned somewhere a boolean switch that would turn off the auto-centring, but it's not in the Wikibook. I vaguely remember it because I've been a member of the forums for a long time, but how would a new user find it? There's also the MeshCenter property but I have no idea how this property works: the WikiBook is rather unhelpful. In the .stc file I don't think either of these options exists.
• The CMOD file utilities are not particularly easy to get hold of, particularly on a non-Windows platform, as the makefile is Windows-specific. In fact I can't seem to get it to work with the latest version of Visual C++. If you build the shiny new Qt4 version, you don't get the library files which are essential for it to run. If you download the Windows executable, there is still no documentation which tells you that you need to have zlib.dll and libpng1.dll in the same folder as the executable. For a cross-platform application this is unacceptable.

Much of this comes down to the tension between maintaining backwards compatibility and fixing bad design decisions. At present it would seem the drive to maintain backwards compatibility is handicapping the ability to make the data files make sense. Even if as experienced Celestia users we've got used to these quirks, it puts a barrier to new people coming into the community.

Then there's the release cycle. The interval between releases is far too long, so in general someone who downloads Celestia for the first time will end up with very old datasets. We need more minor releases so we can get updated data to people who do not compile the source for themselves faster.

Another issue is that the community seems to lose active contributors far more readily than it gains them. Have we got a bit too much like an "old boys club" which has got overly hostile to newcomers?

Andrew, for sure your points are good, but I fear they are not really in the topic. Positioning yourself as a content creator is another category of users; of course we need to address these problems too but they are linked not anymore to the UI but to the very core, the pure code. These are others topic for the dev.
Concerning the community, perso I fear what you point out is a symptom of the leak of clearness in our goals and our working structure. Things are confused so boring so unattractive so "I don't stay in this mess". See what I mean? This is also a VERY important topic, but again not really related to this present thread. Now as we do have a past of difficulties in communications, let's try to do things gently, smoothly. If we can elaborate on the next UI, we will probably have to do the same work about how to resolve the endemic problems of this community.

The exercise here is to help building the best experience for our audience. For that we need to have a clear vision of it, it' needs, it's habits etc... That can sounds easy and straight forward for some people here, but I insist on doing this work because today after years of dev, Celestia is still like a free wheel. Seems we are adding stuff when they came to our mind in whatever order. The result as pointed by Selden are inconsistencies and one may imagine that our code is not that pure and elegant as we would like it to be.

SO, let's be back on topic and a bit later adress these other important problems. Right now we are all users; Pro vs Hobb, any others thoughts?

(BTW, perhaps Pro and Hobb arenot the best to describe our audience; if someone as some different idea, please come on!)

I agree with people who say that Celestia is not above all an educational tool.
But I completely disagree with the fact that its use for educational purposes should
be neglected.
As a professional educator, I've been using Celestia in my astronomy classes not only for
kids but also for teaching other educators during skill training courses. And in all these
situations, I want kids and teachers to be active users, i.e., not to keep watching
passively their screen. On the contrary, I really want them to use Celestia in complete
autonomy, to virtualy manipulate bodies and datas... That's why I think that Celestia
should stay 'adaptable' enough to be usable by people with different skills. This way,
users won't balk at making efforts cause they'll really want to reach the next step and
become confirmed users themsleves.

PS: Hope my post meets your expectation, Doc...

Vincent wrote:I agree with people who say that Celestia is not above all an educational tool.
But I completely disagree with the fact that its use for educational purposes should
be neglected.
As a professional educator, I've been using Celestia in my astronomy classes not only for
kids but also for teaching other educators during skill training courses. And in all these
situations, I want kids and teachers to be active users, i.e., not to keep watching
passively their screen. On the contrary, I really want them to use Celestia in complete
autonomy, to virtualy manipulate bodies and datas... That's why I think that Celestia
should stay 'adaptable' enough to be usable by people with different skills. This way,
users won't balk at making efforts cause they'll really want to reach the next step and
become confirmed users themsleves.

PS: Hope my post meets your expectation, Doc...

Yes and no.
According to my above fractioning of Celestia audience, your are referring to Hobbs. You want them to manipulate datas with ease. How is designed an easy to use UI? Keyword: intuitive. One should find alone how to navigate in the data. This is one of the key aspect of the Hobb side of the problem. We will have to dev this aspect later.

Now you talk about an "adaptable" Celestia. But here you place yourself like Andrew as a dev or content creator. So technically this issue is in itself a whole topic. You seems to do a relation between the fact Celestia could be adaptable and the reaction of the user while using the soft. Perso I see no relation, Celestia adaptable is a dev men/content creator problem and the simple user Pro or Hobb don't care about the process leading to what he have in front of him. See what I mean?

ElChristou wrote:

BobHegwood wrote:...I can think of no better way to
learn about the Solar System and all of it's planets and moons.

Do you mean that in this optic, Celestia is just perfect? You have find enough informations within Celestia and your are happy with it OR Celestia shows you stuff you didn't knew and you dig them outside Celestia? (forum, specialized sites, encyclopedias, etc...)

Didn't say that it was perfect, nor was I speaking only about optics.
It is simply by far the easiest (and most pleasing way) to learn
about the Universe. You can learn in all kinds of ways too. Not only
do you get accurate (for the most part) depictions of places that
cannot be gotten to without spacecraft, but you can also learn almost
anything you want to learn about simply by opening an InfoURL.

What other resource offers this capability? Again, just my opinion
though, so feel free to disagree.

BobHegwood wrote:...Not only
do you get accurate (for the most part) depictions of places that
cannot be gotten to without spacecraft, but you can also learn almost
anything you want to learn about simply by opening an InfoURL...

Right, so for you Celestia is a kind of substrate, a visual base linked to external resources. You pick a point of interest then study it outside. That's a known feature of Celestia; is it good enough form the UI point of view (ease of access)? The Urls are actually contextual, linked to the body you are visiting. Could it be a better approach for this? (the question stand for everybody of course!)

ElChristou wrote:

selden wrote:...It *has* gathered a lot of "cruft" over the years and probably could be improved by getting rid of its many inconsistencies.

Despite I think I understand what you mean here, I find not definition of "cruft"!
Can you dev a bit what in your opinion are these "many inconsistencies"?

Google is your friend!

See, for example,
http://en.wikipedia.org/wiki/Cruft

Some inconsistencies are the units used in the different catalog files: hours vs degrees, km vs au depending on what body is being orbited.

selden wrote:Google is your friend!

See, for example,
http://en.wikipedia.org/wiki/Cruft

Yep, I was searching in some more "academic" resources! Anyway as you probably missed, Andrea gives me the solution a few post earlier... Tx anyway.

selden wrote:Some inconsistencies are the units used in the different catalog files: hours vs degrees, km vs au depending on what body is being orbited.

Right, but these are dev stuff for the core level so I should not ask because we go out of topic, sorry...
Selden, no thoughts for better handling of urls, no thoughts on the differences/needs of Pro vs Hobb?

ElChristou wrote:

BobHegwood wrote:...Not only
do you get accurate (for the most part) depictions of places that
cannot be gotten to without spacecraft, but you can also learn almost
anything you want to learn about simply by opening an InfoURL...

Right, so for you Celestia is a kind of substrate, a visual base linked to external resources. You pick a point of interest then study it outside. That's a known feature of Celestia; is it good enough form the UI point of view (ease of access)? The Urls are actually contextual, linked to the body you are visiting. Could it be a better approach for this? (the question stand for everybody of course!)

Well it could be better, if you would be offered more than one link (InfoURL) to an object. See my ideas here: viewtopic.php?f=2&t=11971
And especially, if the links are still up to date or the website reachable. That could be a problem with the long time between the Celestia releases.

Defining the Educational Activities as Hobbyists is not really the case. I think we should make 3 groups of users:
Professionals
Educators
Hobbyists

Because Educators have other needs for an UI than "normal" "Hobbyists". They need more text to be displayed, more information in an easy way to show and the make it disappear etc.

Frankly, I think deriving multiple "usage profiles" for Celestia is counter-productive in a sense. Why would an educator need different capabilities than a hobbyist or a professional? It depends on the application, not necessarily the person using it.
When one starts to define an application by the "needs" of multiple classes of users, development can become bogged down very quickly. An educator needs this, a professional needs that and a hobbyist needs something else entirely...

"You can only please some of the people some of the time..." So now, instead of developing new and exciting core functionality for everyone, the Celestia devs become mired in pleasing a particular class of user. And, it's not FUN to code anymore...

Look at Sketchup, a wonderful application that can be customized by using Ruby and the published Sketchup Ruby API. Or, if one is more hardcore, there is an C/C++ SDK available. There are literally hundreds of Ruby scripts for Sketchup for everything from exporting to photorealistic rendering engines , to designing staircases or aircraft. Sketchup did not "define" the user base. The users define what they want from Sketchup and they have the necessary tools to do so.

My spin: Make Celestia as "neutral" as possible, stable and optimized for performance and make sure the scripting interface is well defined, coherent and published. Let the end user customize as they see fit within the programs constraints.

If the question is one more of what UI Celestia should have, again, IMO that's a decision the devs can make based on technical expertise and UI code integration concerns.

Cheers.