Advanced lighting?

[Chuft-Captain]

And the CSM is all shiny! This stuff give the impression of one of those old shots a bit blurry! Really nice!

(click to enlarge)

DW,

This is looking pretty good and I too am looking forward to this feature as an option.
Just one minor critique...in the shots provided by ElChristou, the glow extends into space a small distance from the spacecraft.
IMO, to be totally realistic - unless there was some outgassing of fluids from the craft, only the actual surfaces of the craft should glow, and not the surrounding space, as there's not enough gas in the vacuum of space to scatter light (to this extent).

JM2CW.

[Johaen]

DW,

This is looking pretty good and I too am looking forward to this feature as an option.
Just one minor critique...in the shots provided by ElChristou, the glow extends into space a small distance from the spacecraft.
IMO, to be totally realistic - unless there was some outgassing of fluids from the craft, only the actual surfaces of the craft should glow, and not the surrounding space, as there's not enough gas in the vacuum of space to scatter light.

JM2CW.

My understanding of HDR is that the surrounding glow is used to give the impression of increased brightness. That the object is so bright that it's brightness covers up surrounding areas. See Bloom (shader effect) for a better explanation.

[dirkpitt]

Not all glow is due to atmospheric scattering.
For example, some glow is also due to scattering within the optical sensor (human eye included).
Googling for "Veiling Luminance" will give you lots of references on this phenomenon.

My implementation uses a simple combination of 3 gaussian blur filters with blur radii that are constant for every scene.
This isn't physically realistic, but it works as a first approximation.

[Chuft-Captain]

Not all glow is due to atmospheric scattering.
For example, some glow is also due to scattering within the optical sensor (human eye included).

Oh yeah, I forgot about that.

[dirkpitt]

Just in case anyone ever asks, I tried the HDR out on the infamous Microsoft OpenGL 1.1 renderer.
Speed is not much different with/without HDR (i.e., < 1 fps on a slow Celeron!), but otherwise bloom, exposure adaptation etc work perfectly.

[ElChristou]

DW, what are the next steps with this HDR version? Can we hope for better performances or more powerful boards are needed?

[Vincent]

Da Woon,

That looks superb and promising !

Please, could you make your patch available to a Windows user too ?
I'm really looking forward to testing it !

[ElChristou]

Vince, I'm not sure DW will be able to do that, at least at this stage...

[dirkpitt]

Actually, I already have a Windows version ready.
While I suspect at this point that everyone will end up concentrating on the obvious (but known) bugs instead of more subtle issues, still HDR is all about what everyone thinks things ought to look, so feel free to contact me if you want to try it out (e.g., via PM).

My roadmap:
1. Improve the bloom effect ASAP (quality and speed are too low)
2. Apply exposure control to DSO's too. Do not apply bloom to point objects (e.g., zoomed-out planets)
3. Exposure adaptation is too abrupt or incorrect in certain cases, could use some fine tuning
4. Improve overall speed
6. Allow on/off of HDR effects (not just bloom) via hotkey(s)

[ElChristou]

Another cool example showing how nice the bloom effect play on metallic pieces...

(click to enlarge)



(I love this stuff!! )

[BobHegwood]

(I love this stuff!! )

Well I'm glad that you love this stuff. Your expertise certainly
entertains me on THIS computer. Keep 'em coming son...

[T. C.]

Dirkpitt,

i join Celestia since (near around) Winter 2001/2002
(I'm not sure if PM's work correct, it doesn't go from outbox to sentbox, so I post here as well)

However - although I nearly never post here,
(because I am only a "silent user" , not programmer)
I join the forum every week several times

Your marvelously work around the advanced light thing
fulfills exactly my biggest desire to celestia

Finally really bright sun light like reality,
and all the "reflect"-effects (on metal surfaces) as well - stunning - just incredible

You mentioned above,
that we should feel free to write you if we would test it to give you further comments concerning perforance for example

I will be very gratefully if you could make me your brilliant work avaliable

I would test it at my Pentium 4 (3,6 GHz, 1 GB RAM, Open GL 2.0)

I' am very impressed of your work - maybe God has heard my pray

T. C.

[ElChristou]

...i join Celestia since (near around) Winter 2001/2002...

Whaow T.C. ... 2 posts in 6/7 years! You are for sure a VERY silent user!

I don't really know if God has something to do with HDR, but for sure it's a MAJOR feature!
Perhaps you should post from time to time to let dev men know what you want among the rest of the community. More voices, more chance to get what you want!

[dirkpitt]

Nov 10 version improvements:

1. Improve bloom effect - progress is being made. Flickering and aliasing has been reduced I think (Previously, the math for my lowpass filter and gaussians was incorrect)
2. Apply exposure control to DSO's too - done for galaxies.

I'll try and post details soon on some of the math I used for the HDR effects.

[Vincent]

Da Woon,

Thanks for sending your HDR windows build. I've just tested it on my system and the bloom effect really gives an impressive touch of realism.

Here are a few bugs I noticed, though:
- Constellations are weirdly drawn:


- Whereas it shouldn't, the bloom effect seems to apply on clouds, orbits, and also the windows taskbar when it is brought up:


- Galaxies suddenly disappear when exposure > 0, whathever the galaxy light gain or the magnitude limit.

- There's a big difference of luminosity between closest stars and others:


Finally, I get a FOV drop of about 50% on my quite poor config.

[dirkpitt]

Important note I forgot to add:

You must turn OFF antialiased lines!
The bloom effect currently does not work with line smoothing. That explains the weird effects you see on orbits and constellations. FSAA should work fine however.

Regarding the overbright clouds..
Have you installed my shaders? They are absolutely necessary if you're using the Vertex Program render paths.

Also this is the first time I've seen corrupted graphics like your third Earth screenshot. Your config shouldn't matter -
I've tested on some of the worse configs I could think of, e.g., Microsoft OpenGL 1.1, integrated Intel E771, 810 (something like 4MB vram!).
I think ElChristou has the same video card as you do and I haven't heard about corrupted graphics or overbright clouds yet.

[Vincent]

You must turn OFF antialiased lines!
The bloom effect currently does not work with line smoothing. That explains the weird effects you see on orbits and constellations. FSAA should work fine however.

Turning antialising off solved the problem for constellation lines. However, I'm still getting the bloom effect on orbit lines.

Regarding the overbright clouds..
Have you installed my shaders? They are absolutely necessary if you're using the Vertex Program render paths.

Yes, I have.

Also this is the first time I've seen corrupted graphics like your third Earth screenshot.

This only happens with the Vertex Program render paths, not with the Basic / Multitexture render paths. Of course, I'm using the default specularity definitions from the CVS version.

[Fenerit]

Hi, Dirkpitt; I've tested the HDR project. Beautiful, indeed. My finds about of it are similar to that's of Vincent:

1) Obviously my configurations (750 Mhz + GeForce MX 440) can't suitably driven this feature (I get jerks), but it's displayed in all render paths;

2) When I push alt+enter to go in fullscreen mode I get this box:



which desappear once "ignora" (ignore) is pressed, allowing, however, Celestia to go in fullscreen;

3) whether in windowed mode or in fullscreen mode, when I ask for the visualization options I obtain the bloom around the control box as below (just the same for the taskbar, where the bloom assumes the shape of an "Assembler code": that is: 0001000111000!)



For the rest, nothing to say; although the Hubble telescope become completly white just with 0 exposure, in similar manner as the Bob "Brain-Dead Geezer" Hegwood's ISS struggle. The "foggy" view of the Earth is given to me on OpenGl + combiners path. Nevertheless, it's very impressive, expecially with the Sun!

Edit:

I've turned off the antialiasing just now but it's the same; both by turn off it in Celestia or in the Nvidia panel.

[dirkpitt]

Nearby stars are indeed a little too bright on my Windows machine.
I didn't notice this before because stars looked ok on my Mac. Luckily I think the issue is related to incorrect star sprite size scaling and could be a simple fix.

Also thanks for reporting the problem with the exposure "<" and ">" controls for stars and galaxies. Still need to figure out what's going on here..

[chris]

Hi, Dirkpitt; I've tested the HDR project. Beautiful, indeed. My finds about of it are similar to that's of Vincent:

2) When I push alt+enter to go in fullscreen mode I get this box:

This problem is unrelated to the HDR patch. I checked in a fix for it just yesterday.

--Chris