celestia-g2-stereoscopic

Please read on in the wiki

celestia-g2-stereoscopic WIKI

I'll use the readme.md for progress informations.

About this

Please first refer to https://github.com/bgodard/celestia-g2 on how to build (and install).

This repository just holds my modifications for stereoscopics, so you may test or improve them. I'm busy with blender and other building yards at the moment, so I decided to publish that "unready" code. It's ready enough to enjoy stereoscopics. We need to have one repository for the project, so I didn't fork.

There are modifications in

• .trunc/src/celestia/celestiacore.cpp
• .trunc/src/celestia/celestiacore.h
• .trunc/src/celengine/axisarrow.cpp
• .trunc/src/celengine/render.cpp

You'd need these 4 files from here copied to your local clone path from celestia-g2 and compile it (again). Download as zip (or clone it via git). The patched files are working with the origin svn repository trunc as well. Since autotools are broken with celestia (on Linux wtf!) at all, you'll need qmake before make. I'll take a look at the arising compiler warnings later on, too.

Update (7/2015)

For now we've a stereo class, and a small dockable qt widget for stereo settings, so we could easily tinker around with more values belonging to stereoscopics. I don't know if we need to have updated UI values from core-values, maybe we could skip the shifted "core-keys" later on.

Marginal note: Please don't mess up stereoscopics with virtual reality, only "marketing" does that, and they do not know what VR represents at all.

For the qtwidget you'll need another 5 files the new ones:

• ./trunc/src/celestia/qt/qtstereosettings.h
• ./trunc/src/celestia/qt/qtstereosettings.cpp

the updated (just to include the widget):

• ./trunc/src/celestia/qt/qtappwin.h
• ./trunc/src/celestia/qt/qtappwin.cpp

And the patched pro-file celestia.pro (qmake)

• ./trunc/celestia.pro

and last but not least a "new" splash image which is more compatible with 1bit alpha channeling

• ./trunc/splash-g2.png

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You may just overwrite them in your local clone, but there are patch files in ./patches as well, so you could easily see over what I've done in terms of stereoscopics.

If you want to push pixels within splash-g2.png, please take a look in

./splash

which includes the newer splash.png gimp sources.

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Besides from development you might use my linux 64bit binary, which should also work within a 1.6.x installation. Find the installed celestia binary copy celestia_stereo_x86_64.bin into there and just run it. You'll need the ./trunc/splash-g2.png within celestia installation path as well. Check the md5sum, do NOT run as root ... you know.

./bin

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As already mentioned, stereoscopic views are working with a known little weakness on travelling through far distances. This is a proof of concept on how to modify the engines roof, to have stereoscopic view, even for head mounted displays later on. We don't loose FPS, 'cause the magic is called interlacing. For having realtime stereoscopics on different projection types there is IMHO no other reasonably place than the core itself. For rendering videos I'll implement that thing without interlacing, so the videos become more smooth. Doing steroscopics with LUA is possible as well, but we need to be near to hardware for shutters hmd and whatever comes up in the future. I'll contribute more on this issue, but I don't own a hmd yet, I'm waiting for "quadbuffering", and I need a period of time to be in the code again, there are several things to do, and I've some other ideas which we could implement.

So there are many of you like me who want celestia to be continued, let's say celestia took a well-earned rest ;-). The forum has been reborn, so there are only milestones on the way. At least good software is never "ready" or perfect, and I am pretty sure, we will continue this brilliant project. Of course!

Essentially my modifications will work on any platform, maybe there are issues which I can't expect without testing. e.g. there were issues with Mac and F2/F3 Keys in 2009. Now there's a qt-widget

##-------------

Build and use (Linux): For testing purposes you even don't need a final "make install", you may run the binary out of your local clone path, and solve the -z's issue, before I do ;-)

For now, F-Keys used are:

• SHIFT+F2 OR F3 will toggle between "normal" "anaglyph" "shutter" "shutter_inverted" "crossed-eyed" "normal" and so on The modes themselves will be easily to be extended, e.g. "head-mounted-display" or whatever.

• SHIFT+F5/F6 increase/decrease stereo depth which is nested with parallax point for now.

• SHIFT+F7 switches internal defined left/right, well a kind of debug/research thing at all, but there's still no real standard on this issue afaik.

• OR use the new dockable qtwidget for these settings

Platform independent unused keys are rare in celestia, so we should build a stereo-menu later on.

BTW: realtime communication rocks, never hesitate to join irc.freenode.net/#celestia

Technical Notes for now

1. anaglyphic mode

   red-cyan glasses needed other anaglyph methods won't be supported (by me)

2. crossed-eyed-view mode

   for realtime stereoscopics without any utility and for recording hardware-independent stereo-videos; If you know about "crossed-eye"-stereos, and if you own two monitors, you may imagine the terrific effect … ) Please note, at the moment we just have a "splitted view" with two situations at all. The active (splitted) view will be rendered as single stereo scene, while the inactive situation remains in "background". Not very user-friendly, I know, but that'll be solved later on, too. We also could do the same for above/under-stereo by horizontal split. It still uses to turn off verbosity manually, the "verbose"-text cannot be displayed on both sides, so it is confusing our brain (not our eyes) while turned on. Those modes will be a little more "special multi view" internally, so that the user don't need to take care of this.

   parallel-eyed-view mode (not implemented yet - wait, Shift+F7 does this job at the moment) I believe some stereo-video-players need it this way.

3. support for shutter-glasses

   At least vblank-synced should work, but experimental, I don't own a quadbuffer, but sli consumer, so I cannot test. On weak machines it will flicker sometimes, it won't if celestia could drive the sync to the glasses itself. Hopefully nvidia tells us how to drive their ir-transmitter finally, to have more fun with Linux and their consumer cards. I'd love to hear from nvidia Linux+consumercard+stereo=no problem, In the end, we would just need to know how to sync the glasses via usb without having a vsync signal to it, in other words syncing by software, instead of hooking and modifying the scene by the gpu-driver like they do with directx Just for the fun on computing, you know. Or. if there's anyone out there who has figured out, help is appreciated, afaik we are lack of some ansi escape codes …

Updated notes on shutters [9 2015]

After some more investigations on nVidia shutters, I have created an open letter
to nVidia, because there is defacto no technical reason why they do not support
quadbuffering on Geforces lastly with Linux and Co. I knew about that in abstract,
now I know from my practical experience.

[open letter to nVidia](https://github.com/raeTen/celestia-g2-stereoscopic/blob/master/open-letter-to-nvidia.md)

Shutter-glasses in general require quadbuffering for the following reasons:

* no need for "dirty" platform-dependent tricks
* keeping the first defined eye render process in sync with shutters in stable manner

quadbuffering also makes it a lot of easier to modify any 3D-application to be stereoscopic
even if this is not required for other projection types than shutter-glasses.
After all I can also state that there is no real "problem" having quadbuffering on Geforces at all.
Let's see how nVidia reacts, if the reaction is negative at that point, I'm going to
obtain an competioner product with quadbuffering support on Linux. After that I'll be
able to make celestia ready for shutterglasses at all. BTW the code works with lack
of keeping "first eye" in sync with blanking. I worked around that issue, but that
would be "Linux only". That is not what we want, because I just love the open-source community
for the paragon of democracy. The fact and decision to develop with Linux only, doesn't mean that
I want to exclude any other platform. I am pretty sure that this is our common position.
The religious fundamentalists ever could be found in the "Windows only-camp", that's nothing
I stand for.
…

4. roadmap with topic to stereo: support for headmounted-displays (and other displays) internal 3D mouse-pointer (3D HID needed )

A lot of bits and bobs to do - as always :)

#Updated notes and thoughts…

Thoughts on celestia development in general

Apart from stereoscopics and my gaining experience with modelling, I tumbled over issues associated with the 3ds format. I didn't find a way to have an exported 3ds (scene) which is being (imported) exposed correctly by celestia. I tried actual modelling software like blender, Wings3D and so on. (even lightwave but not autodesk yet). If I import a correct working 3ds file (e.g. isscomplete.3ds) to blender (2.6x >), blender poses this correctly, but then exporting it without any modifications will make the 3ds unusable with celestia. I believe something went wrong with the chunks according to material/transparency, and that already happens while importing to blender, but i don't know yet for sure. That worked in the past didn't it?

No one to blame for, that holy shit (pardon) is just sophisticated matter. Unfortunately 3ds is still proprietary, but "well known" over the years. Even with its doslike limitations it would be sufficient for cel things. They have "max" these days, they won't hurt themselves to make 3ds an open format as a standard, simple and interchanging (what it is) format, right? It would be just the contrary, because the complete IT world would be just nothing without open formats and standards. I would never blame closed source software devs, but we should blame those who want to hide supposedly secrets for ages and fleecing the general public. First and foremost the parted knowledge is the thing, which keeps the scientific headway. J.C. and id-soft is a shining example HOW it works.

To cut a long story short: Free software for free software ;-) I read about the cmod exporter for historic blender versions. This is the thing we need in future if you ask me, because we want to be platform-independent and not dependent on these mystic-monger ;-).

Fixing the thing with 3ds parsing/importing/exporting for blender OR within celestia importer would be very nice. I don't have a clue in detail yet, so helping out with this is very very much aapreciated. If anyone has got a copycat "cmod-exporter".py for blender (2.4 <) - please make it public again, it was linked within the original forum, which is still down :-/ Porting that to blender 2.7.x > should be the easiest way.

Finally:

Thanks to everybody (and especially to the NASA), who worked on celestia, I just love this piece of software. I'm sure Pluto and Charon will get a nice texture these days! I'll contribute more, but meanwhile I'm busy with blender again …