Lua Edu Tools beta version

[Paolo]

Hello Vincent is it possible to add some "inclination" to the compass in order to reduce the amount of space covered adding some "3D effect"?

Is it possible to define the position of the compass? Left-Right-Middle
Is it possible do define the amount of transparency of the compass?

Kind regards

[fsgregs]

Ramon,

The current version of Celestia Edu doesn't integrate the sound playback.
I don't know if Hank has got some plans about this...

Vincent/Hank:

Is this true? Sound is a VITAL part of a Celestia educational version. Its use is wonderful in a computer lab or home setting. The sub-routine MUST be in Celestia-edu. Did you take it out on purpose?

Wouldn't it be easier and cooler to integrate those bottons in the cockpit, in other words, redesign the cockpit so that the buttons would fit into it?

Frank,
I'm for Anders' idea. I'll mind the Celestia-ED version when I'm finished with the Lua Edu Tool.

What about overlay textures? Will the ship cockpit overlay be in this new edu version? If not, that too is most distressing. My students LOVE the cockpit.

If the cockpit overlay is present, then the position of the compass and taskbar at the bottom of the screen is an issue. A circular compass would be located smack in the middle of some gauges and dials on the cockpit.

Here is a cockpit screen as currently displayed in a 1024x768 display:



You have been a wonderful resource to kids all over the world. Your educational version of Celestia is already inside hundreds of classrooms in over 20 countries now. I know this is a lot to think about. However, if this new version is being designed for use in a classroom or by students at home or in a computer lab, then I beg you to accomodate all our needs ... a taskbar ... a compass ... sound and cockpit overlays. It just has to be laid out that way.

convenez-vous ?

Frank

[Sui Ota]

I tested new test version...

- No more localization problem. Just edit the 4 characters in the compass.png image. A compass.psd file containing all the layers is provided in the 'images' folder.

What a surprising solution it is!

I was testing a new function that brings the observer to a distance from selection that makes it fit the screen, for any value of fov. That is particularly useful when the users wants to quit the planetarium mode and select new values of longitude and latitude. That works perfectly for planets, stars, etc..., but unfortunately, not for locations, as you noticed, because their radius is too small.

I can allocate this function to the [shift]+[G] keys, instead of the single [G] key. This way, both the standard 'goto' and the new 'gotoToFit' function will be available...

Oh, it is actually useful! I had rushed for a conclusion...


Viewpoint problem on the surface of an object:
With enabling compass and alt-azimuth mode, and keeping left or right arrow key pressed, the camera suddenly bend down its head at the low elevation(about 0~30 degrees, especially when the horizon is in sight).
(This already exists in former version.)

[Vincent]

Is this true? Sound is a VITAL part of a Celestia educational version. Its use is wonderful in a computer lab or home setting. The sub-routine MUST be in Celestia-edu. Did you take it out on purpose?

Frank,

As we did for the Information Text and Images, we will do our best to add the possibility to play sound, and even video to the celestia Edu Tools, since they're both very important educationnal means.

What about overlay textures? Will the ship cockpit overlay be in this new edu version? If not, that too is most distressing. My students LOVE the cockpit.

You must care about the difference between the ED features that will be used via the Lua Edu Tools, and the ones that will be used via scripts.

If you're keeping the logic of the previous version of Celestia-ED, the cockpit overlay texture needs to be displayed via a script. This also applies to the sound playback... The Lua Edu Tools have (almost) nothing to do with celx scripts...

Hank and I will mind the possibility to use the Lua functions (overlay textures, etc...) using celx scripts after the Lua Edu Tools are ready to be released.

Paolo, Sui Ota,

I'll reply to your posts in a couple of hours.
Have to go back to my professionnal work now....

[Chuft-Captain]

As you suggested, I first wanted to set the standard format to little-endian (day/month/year). But that would have required a 'en.lua' localization file to be added to give the possibility to native english users to use the middle-endian date format (month/day/year).
But if a majority of native english users also want to use the little-endian format (day/month/year), I will set it as the default one...

No big deal, Vincent.
I wonder if LUA can just pick up the appropriate formats to use from the culture/locale set in the user's OS? eg. In Windows: "Regional and Language Settings"

Regarding your comment about native english users, I think date format preference has more to do with locale and personal preference, than language spoken. eg. AFAIK, most of Europe would usually use either little or big endian, regardless of native language. (I may be wrong though)

[Vincent]

Hello Paolo,

Hello Vincent is it possible to add some "inclination" to the compass in order to reduce the amount of space covered adding some "3D effect"?

Well, the current Lua functions that call Celestia Core OpenGL functions only support 2D rendering. Changing the code in celx.cpp to allow the Lua code to use 3D OpenGL functions would be easy. But then, I don't feel like dealing with 3D rendering for now...
As we talk about 3D rendering, the nicest way to render the compass would be to use a cylinder with a base parallele to the ground and that would rotate around the UP axis... I think that would satisfy everybody. But sorry, I'm not Chris...

Is it possible to define the position of the compass? Left-Right-Middle

Hank has already added the possibility to move the different boxes with a left drag. However, that would be a little bit complicated to code for the compass since it has to rotate around its center...
Then, it would be possible to give the user the possibility to choose between 3 fixed positions, like the one you've suggested : Left-Right-Middle. But that would require again to add a new setting box...

Is it possible do define the amount of transparency of the compass?

Again, that could be easily done via a setting box, with a slider... I just fear that Lua tools become too complicated to use...

[Vincent]

Viewpoint problem on the surface of an object:
With enabling compass and alt-azimuth mode, and keeping left or right arrow key pressed, the camera suddenly bend down its head at the low elevation(about 0~30 degrees, especially when the horizon is in sight).
(This already exists in former version.)

Sui Ota,

Is this issue still happening with the latest update of the Celestia_edu_1pre3.zip file ? I thought I had fixed this bug... Besides, I can't reproduce it on my system...

I wonder if LUA can just pick up the appropriate formats to use from the culture/locale set in the user's OS? eg. In Windows: "Regional and Language Settings"

CC,

The os.date() lua function returns the date with the locale format, e.g. like "09/11/2006". Of course, we can't use it since we need the simulation time, not the current time. And it's not possible to get the local format from this string, since it could be 09/Nov/2006 as well as 11/Sept/2006...

Regarding your comment about native english users, I think date format preference has more to do with locale and personal preference, than language spoken. eg. AFAIK, most of Europe would usually use either little or big endian, regardless of native language. (I may be wrong though)

I was assuming that middle endian users could only be found among the native english users. Anyway, I will follow your suggestion and set the little endian format (day/month/year) as the default one.

[Sui Ota]

Is this issue still happening with the latest update of the Celestia_edu_1pre3.zip file ? I thought I had fixed this bug... Besides, I can't reproduce it on my system...

I first downloaded Celestia_edu_1pre3.zip only after 5 minutes by you posted the link.
I downloaded the file again, and I could not reproduce the bug no longer.

[Paolo]

I was assuming that middle endian users could only be found among the native english users. Anyway, I will follow your suggestion and set the little endian format (day/month/year) as the default one.

I would like to suggest Big endian as default. Year month day. So everyone will have to change a bit and there won't be never mistakes.

kind regards

[Jedi]

Has anyone else noticed that the time in displayed in the new box is always 1 min 5 sec ahead of the system time. Clearly the objects are placed according to the system time. Why the difference?

[selden]

Because the time used within Celestia to calculate spacecraft and other locations is what is known as barycentric dynamical time, or TDB. The time shown on the display is UTC, which includes leap seconds and other offsets which TDB does not.

For more details, please see http://en.wikibooks.org/wiki/Celestia/Time_Scales
which Chris created just recently.

[chris]

Because the time used within Celestia to calculate spacecraft and other locations is what is known as barycentric dynamical time, or TDB. The time shown on the display is UTC, which includes leap seconds and other offsets which TDB does not.

For more details, please see http://en.wikibooks.org/wiki/Celestia/Time_Scales
which Chris created just recently.

Selden's right. The normal time display shows UTC, but the Lua EDU time display shows barycentric dynamical time. We need to add some time conversion functions for Lua so that it can also display UTC.

--Chris

[Vincent]

Has anyone else noticed that the time in displayed in the new box is always 1 min 5 sec ahead of the system time. Clearly the objects are placed according to the system time. Why the difference?

Because the time used within Celestia to calculate spacecraft and other locations is what is known as barycentric dynamical time, or TDB. The time shown on the display is UTC, which includes leap seconds and other offsets which TDB does not.

For more details, please see http://en.wikibooks.org/wiki/Celestia/Time_Scales
which Chris created just recently.

Yes, I've also noticed that. Fortunately, I had read Chris' explanation on the dev mailing list a few days before :
http://sourceforge.net/mailarchive/foru ... um_id=9864
If not, I could have searched a clue for a very long time...

[Vincent]

Is it possible to define the position of the compass? Left-Right-Middle

OK, I have something even better : you can now move the compass box anywhere on the screen.
> http://vincent.gian.club.fr/celestia/Ce ... _1pre3.zip
Just click in the compass to display the red background, and then click and drag from one corner of the compass box.

However, the size of the compass box now varies with the screen size... I hope I'll find a fix, though it doesn't look that simple...
That was the reason why I had first unactivated the possibility to move the boxes.

[EDIT]

Oops, I forgot to remove the display of some test values... It's OK now.

[/EDIT]

[Vincent]

However, the size of the compass box now varies with the screen size... I hope I'll find a fix, though it doesn't look that simple...
That was the reason why I had first unactivated the possibility to move the boxes.

OK, I've found a solution to that problem, making the compass box go back to its initial position when the size of the screen has changed.

Would you find it useful to make all other boxes (time, light, text,...) movable ?

I've also found a way to unactivate the display of the standard time when a Lua Hook is declared in the celestia.cfg file. That way, only the Lua Tool Time box is displayed at the top right hand corner of the screen. In fact, the standard Time is simply replaced by the Lua Time Box.

However, I had to change the Core code, adding a displayTime boolean value (celestiacore.cpp/celestiacore.h files).

Chris, Hank, please let me know if you're OK with these changes :
> http://vincent.gian.club.fr/celestia/displayTime.patch

[Paolo]

Hello Paolo,

Hello Vincent is it possible to add some "inclination" to the compass in order to reduce the amount of space covered adding some "3D effect"?

Well, the current Lua functions that call Celestia Core OpenGL functions only support 2D rendering. Changing the code in celx.cpp to allow the Lua code to use 3D OpenGL functions would be easy. But then, I don't feel like dealing with 3D rendering for now...
As we talk about 3D rendering, the nicest way to render the compass would be to use a cylinder with a base parallele to the ground and that would rotate around the UP axis... I think that would satisfy everybody. But sorry, I'm not Chris...

It should be not so difficult.

Code: Select all

drawcompass = function ()
   local az_rad = az*3.14159/180;
   lb,bb,rb,tb = compassFrameBox:bounds();
   celestia:print(tb.." "..tb0)
   local xlb, ylb = rot(lb, bb, az_rad);
   local xrb, yrb = rot(rb, bb, az_rad);
   local xrt, yrt = rot(rb, tb, az_rad);
   local xlt, ylt = rot(lb, tb, az_rad);
   compassImage:bind();

   local zval = 1;
    -- Prepare 3D environment

   gl.MatrixMode(GL_PROJECTION);
   gl.PushMatrix();
   gl.LoadIdentity();
   glu.Perspective(35, width4/height4, 0.1, 1000);
   gl.MatrixMode( GL_MODELVIEW );
   gl.PushMatrix();
   gl.LoadIdentity();

   gl.Rotate(0.15,0,0);

   --  Draw 3D texture   
   gl.Enable(gl.TEXTURE_2D);
   gl.Begin(gl.QUADS);
   gl.Color(1, 1, 1, 0.5);
   gl.TexCoord(0, 1); gl.Vertex(xlb, ylb, zval);
   gl.TexCoord(1, 1); gl.Vertex(xrb, yrb, zval);
   gl.Color(1, 1, 1, 0.5);
   gl.TexCoord(1, 0); gl.Vertex(xrt, yrt, zval);
   gl.TexCoord(0, 0); gl.Vertex(xlt, ylt, zval);
   gl.End();
   gl.Disable(gl.TEXTURE_2D);   

                -- restore 2D environment
   gl.MatrixMode(GL_PROJECTION);
   gl.PopMatrix();
   gl.MatrixMode(GL_MODELVIEW);
   gl.PopMatrix();

          end


It should work.... I think but I'm not an OpenGl guru too....

Kind regards

[Vincent]

Paolo,

The problem is that we can't use all the OpenGL functions directly in the Lua code. There's no binding of the OpenGL functions currently integrated into the Celestia code. For example, the glu.Perpective and gl.Rotate functions are not available. Just check the celx.cpp file to know what are the (2D) functions currently available.

So, before trying your piece of code, I had to implement these two functions, along with the Vertex3D function. Then, I've made the needed changes in your compass.lua file... unfortunately, with no result : the compass image is not displayed anymore. Maybe you just have to make some more testing with your different values. If you wish to do so, I can send you the recompiled celestia_edu.exe file that integrates the needed openGL function, along with the modified compass.lua file. Just let me know...

Chris, Hank, just a thought : wouldn't it be more interesting to integrate the LuaGL library to the code, since LuaGL contains the binding of all the OpenGL functions ?
> http://luagl.sourceforge.net/

[Joe]

wouldn't it be more interesting to integrate the LuaGL library to the code, since LuaGL contains the binding of all the OpenGL functions

Not only interesting, it will also be an extremely useful and flexible feature with which rendering addons can be developed without touching the core code.

[Paolo]

Sorry Vincent, but I think that I've missed something very important. When moving in 3D space using gluPerspective probably your LUA tools uses the same "space" of celestia and so the vertex coordinate values are almost meaningless. Here we need the support of someone more competent in OpenGL.

Kind regards

[Joe]

It seems that the latest CVS source (23rd November) has all code for Lua Edu Tools, after I have built an Win32 Celestia.exe, everything works well but those Lua hooked features as in Vincent's previous versions do not. Anyone has a latest Win32 CVS built that has such features work?