Advanced lighting?

[t00fri]

Wow. It looks very impressive, but why it isn't available for "simply users"?

Can we expect some link to this build? Or we most waiting for Celestia 2.0. final release?

Because it's still development matters as the title of this thread says.

Bye Fridger

[MFN1444]

Because it's still development matters as the title of this thread says.

OK I understand It was a stupid question... Sorry if it was irritating for You t00fri.

I have another question (perhaps also stupid). When we can except HDR feature in Celestia pre-release or final version? Is it matter of weeks, months or years?


regards

[dirkpitt]

I'm not offering any downloads at the moment, because there are a couple of obvious issues that I'm trying hard to fix (most notably, the completely incorrect rendering on buggy cards like the GeForce4 MX).

There is currently no set timetable for release, but development is active - keep watching this thread for weekly updates.

What I'm working on right now:
- GF4 MX fix
- Cloud brightness regression bug

Planned:
- Fix for sun < 1 ly going dark too quickly (if luckly, might only require a simple clamping operation)

[MFN1444]

Thank You dirkpitt for response, sorry for my newbie questions and good luck!


regards

[dirkpitt]

Here is a new HDR Celestia build:

Download Jan 1 HDR build (Mac OS X only)

Changes:
- GF4 MX bloom bug fixed
- Cloud brightness fixed
- Star halo brightness changes more sanely in the 0 to 1 ly range
(stars no longer pop in/out at around 7 au, and the Sun is visible again from Pluto)

Known bugs:
- Star halo may abruptly change size at 1 ly
- Planets too bright in the OGL2 render path

Happy New Year everyone!

[ElChristou]

Tx DW, wil go for a test right now. One thing, as I suppose you are working on a different source, could it be possible to change the name of the shaders we need to use with this version? (this way we could have these new shaders coexisting with the regular ones without trouble)

[ElChristou]

DW, don't know about OGL2, but in older render paths, the planets are too dark. Models are just right.

[dirkpitt]

One thing, as I suppose you are working on a different source, could it be possible to change the name of the shaders we need to use with this version?

Sure (Why didn't I think of that before? Thanks!)

[dirkpitt]

DW, don't know about OGL2, but in older render paths, the planets are too dark.

How dark? Half-brightness?

[ElChristou]

DW, don't know about OGL2, but in older render paths, the planets are too dark.

How dark? Half-brightness?

Possible, bit it's hard to say visually... I'll send you a shot by mail.

[dirkpitt]

I've reproduced the issue - turns out I was using 3rd-party texture addons. I'll still need to do some more testing.

[ElChristou]

Am I the only one who test DW's HDR version? ok we are not numerous under osX but feedback IS important...

[dirkpitt]

That's ok Christophe, it'd nice though if I could get more GF4 MX feedback and I'm also curious about results on the Intel GMA 900 + Leopard 10.5. A very quick test on a friend's machine with Leopard 10.5 on the GMA900 was not so hot (star rendering was incorrect) and I still need to figure out the reason.

Also, Ota-san (Sui) reported issues with Celestia (no HDR) on a recent Intel iMac so I'm curious about that too..

[FaLLeN_SOuL]

Am I the only one who test DW's HDR version? ok we are not numerous under osX but feedback IS important...

you would get more feedback with a windows build i think. i don't know anybody that is using osX.

[ElChristou]

...i don't know anybody that is using osX.

That's funny to say that when you talk to someone who use osX...

[BobHegwood]

That's funny to say that when you talk to someone who use osX...

Welcome to my world. Hee, hee.

[dirkpitt]

My main development platform is OS X. I can compile for Windows, but for me it's a chore so it'll have to wait.

Anyway...
ElChristou and I were talking about night textures and how their brightness is unrealistic in the current version of Celestia. For example, using the classic DMSP data we're looking at about max 4e-6 W/m^2 of radiated power per pixel, which is pretty dim (even accounting for night vision adaptation). Dimming the texture itself is a start, but I wonder if it would be enough, given the low dynamic range of the texture. But there are more problems: Existing textures would be unusable, and given an arbitrary dimmed texture, there's no way to tell what the actual range of radiances are without forcing some assumptions.

An ssc definition, named something like NightRadiance, could specify the actual maximum night light radiance (in standard units). This could be used to light and expose night lights correctly.

[dirkpitt]

New build: Celestia_UNOFFICIAL_dirkpitt_build_20080122HDR.zip
Installation instructions: Copy all included shaders into your existing shaders folder, overwriting existing files
(overwritten shaders will remain compatible with non-HDR Celestia).
Also copy the "earthnight" addon into your extras folder. This addon contains a single ssc that defines a new NightLightRadiance value.
This lets you specify the maximum radiance represented in the night texture (units are W sr^-1 m^-2)

Changes
- Haze brightness corrected (only nvidia cards apply)
- Ambient light brightness corrected. Note: Use of ambient light is NOT recommended.
Constant ambient light as used in Celestia gives unrealistic lighting, this unpleasant fact is exaggerated in HDR!
I suggest always setting your ambient slider to zero. (No ambient light)
- Radiance-scaled night lights with exposure adaptation. See screenshots below:

Night lights almost invisible with bright side of Earth showing:


Night lights becoming more visible as sun sets (click to view larger versions):


Sun fully eclipsed - night lights, while still faint, are now clearly visible.