Brightness in different games

General discussion about nGlide.
Post Reply
vech32
Posts: 15
Joined: Tue Jun 14, 2016 7:17 pm

Brightness in different games

Post by vech32 » Sun Jul 14, 2019 2:08 pm

Different games set different brightness. For example, Quake and Quake 2, by default, start up with different brightness. Q1 (GLQuake can't adjust the brightness, but it doesn't matter) is too dark and Q2 (using default vid_gamma = 1) is too bright. The difference is clearly visible even on the 3dfx splash screen. If I want exactly same brightness for Q1 and Q2, is it possible to find out what final brightness level is set? Maybe there is some debug info? I can increase the brightness for Q1 in the nGlide Configurator and decrease it for Q2, but I don't know which values to use. Or is it possible to lock the brightness in the wrapper so that the game can not change it?

User avatar
Zeus
Site Admin
Posts: 1628
Joined: Sun Sep 21, 2008 2:51 pm
Contact:

Re: Brightness in different games

Post by Zeus » Sun Jul 14, 2019 3:23 pm

Q2 in 3dfx mode uses very unusual mechanism to set gamma correction. You can reset it to Q1 level (gamma=1.0) simply by moving brightness slider to the far left, but the trick is, you also need to restart the game completely to see changes.

vech32
Posts: 15
Joined: Tue Jun 14, 2016 7:17 pm

Re: Brightness in different games

Post by vech32 » Sun Jul 14, 2019 8:56 pm

Can you tell how much the in-game brightness slider in Q2 affects the wrapper's gamma? It doesn't look like changing vid_gamma by 0.1 is equal to changing gamma in the nGlide Configurator by 0.1.

User avatar
Zeus
Site Admin
Posts: 1628
Joined: Sun Sep 21, 2008 2:51 pm
Contact:

Re: Brightness in different games

Post by Zeus » Sun Jul 14, 2019 11:53 pm

The slider has 9 positions. A final 3dfx gamma in Q2 is calculated from vid_gamma with this equation:

Code: Select all

final_gamma = 2.0 * (0.8 - (vid_gamma - 0.5)) + 1.0
thus:

Code: Select all

slider pos - vid_gamma - final_gamma:
1 - 1.3 - 1.0
2 - 1.2 - 1.2
3 - 1.1 - 1.4
4 - 1.0 - 1.6
5 - 0.9 - 1.8
6 - 0.8 - 2.0
7 - 0.7 - 2.2
8 - 0.6 - 2.4
9 - 0.5 - 2.6

vech32
Posts: 15
Joined: Tue Jun 14, 2016 7:17 pm

Re: Brightness in different games

Post by vech32 » Mon Jul 15, 2019 11:06 am

Thank you very much! According to this information, Q1 with nGlide gamma set to 1.2 and default Q2 with 0.6 will have the same brightness level, and it really looks like this.

And can you also tell the same information for Unreal brightness slider, please?

User avatar
Zeus
Site Admin
Posts: 1628
Joined: Sun Sep 21, 2008 2:51 pm
Contact:

Re: Brightness in different games

Post by Zeus » Mon Jul 15, 2019 9:57 pm

In UE1 games it is:

Code: Select all

final_gamma = (1.5 * Brightness) + 0.5

Code: Select all

slider pos - Brightness - final_gamma:
1 - 0.2 - 0.8
2 - 0.3 - 0.95
3 - 0.4 - 1.1
4 - 0.5 - 1.25
5 - 0.6 - 1.4
6 - 0.7 - 1.55
7 - 0.8 - 1.7
8 - 0.9 - 1.85
9 - 1.0 - 2.0
Brightness setting is located in [WinDrv.WindowsClient] section in game .ini file.

vech32
Posts: 15
Joined: Tue Jun 14, 2016 7:17 pm

Re: Brightness in different games

Post by vech32 » Tue Jul 16, 2019 12:18 pm

Thank you! Am i right assuming that 0.5 in the equation is actually (gamma - 0.5), so if I, let's say, increase the gamma in the nGlide Configurator from 1.0 to 1.2 then the slider in position 4 will give final gamma 1.45?

User avatar
Zeus
Site Admin
Posts: 1628
Joined: Sun Sep 21, 2008 2:51 pm
Contact:

Re: Brightness in different games

Post by Zeus » Fri Aug 23, 2019 6:34 pm

The difference from configurator will be added to final_gamma, so yes, 1.25 will become 1.45.

Post Reply