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OpenGL2: Remove misleading documentation for gamma cvars.
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SmileTheory committed Apr 23, 2014
1 parent b9b6703 commit 7beff8b
Showing 1 changed file with 14 additions and 78 deletions.
92 changes: 14 additions & 78 deletions opengl2-readme.txt
Expand Up @@ -18,7 +18,6 @@ compatibility with existing Quake 3 mods.
- Texture upsampling.
- Advanced materials support.
- Advanced shading and specular methods.
- Separate material/light/framebuffer/tonemap gamma.
- LATC and BPTC texture compression support.
- Screen-space ambient occlusion.

Expand Down Expand Up @@ -311,29 +310,6 @@ Cvars for the sunlight and cascaded shadow maps:
4096 - 4096x4096, indistinguishable from
2048.

Cvars for adjusting gamma values:
r_materialGamma - Gamma level for material textures.
(diffuse, specular)
1.0 - Quake 3, fastest. (default)
2.0 - More accurate, slower.
2.2 - Most accurate, slowest.

r_lightGamma - Gamma level for light.
(lightmap, lightgrid, vertex lights)
1.0 - Quake 3, fastest. (default)
2.0 - More accurate, slower.
2.2 - Most accurate, slowest.

r_framebufferGamma - Gamma level for framebuffers.
1.0 - Quake 3, fastest. (default)
2.0 - More accurate, slower.
2.2 - Most accurate, slowest.

r_tonemapGamma - Gamma applied after tonemapping.
1.0 - Quake 3, fastest. (default)
2.0 - More accurate, slower.
2.2 - Most accurate, slowest.

Cvars that you probably don't care about or shouldn't mess with:
r_mergeMultidraws - Optimize number of calls to
glMultiDrawElements().
Expand Down Expand Up @@ -381,7 +357,20 @@ Cvars that you probably don't care about or shouldn't mess with:
r_shadowCascadeZBias - Z-bias for shadow cascade frustums.
-256 - Default.


r_materialGamma - Gamma level for material textures.
(diffuse, specular)
1.0 - Quake 3, fastest. (default)

r_lightGamma - Gamma level for light.
(lightmap, lightgrid, vertex lights)
1.0 - Quake 3, fastest. (default)

r_framebufferGamma - Gamma level for framebuffers.
1.0 - Quake 3, fastest. (default)

r_tonemapGamma - Gamma applied after tonemapping.
1.0 - Quake 3, fastest. (default)

Cvars that have broken bits:
r_dlightMode - Change how dynamic lights look.
0 - Quake 3 style dlights, fake
Expand Down Expand Up @@ -615,59 +604,6 @@ Each of these settings corresponds to a matching cvar, so you can view and
adjust the effect before settling on fixed settings.


-------------------------------------------------------------------------------
MATERIAL/LIGHT/FRAMEBUFFER/TONEMAP GAMMA
-------------------------------------------------------------------------------

This adds four cvars, r_materialGamma, r_lightGamma, r_framebufferGamma, and
r_tonemapGamma. These adjust the gamma levels of their corresponding texture
or color, allowing for more realistic lighting and shading.

These settings are fastest:

r_materialGamma 1
r_lightGamma 1
r_framebufferGamma 1
r_tonemapGamma 1

This is the same as Quake 3 behaviour, where colors are not adjusted for gamma
until presentation to the screen.

These settings are more accurate:

r_materialGamma 2
r_lightGamma 2
r_framebufferGamma 2
r_tonemapGamma 2

This converts diffuse/specular from gamma 2 space to linear space
(r_materialGamma 2), converts light values similarly (r_lightGamma 2),
converts those to the gamma 2 of the framebuffer (r_framebufferGamma 2), and
converts to a monitor gamma of 2 after tonemapping (r_tonemapGamma 2).

These settings are the most accurate:

r_materialGamma 2.2
r_lightGamma 2.2
r_framebufferGamma 2.2
r_tonemapGamma 2.2

This is the same as the previous, except using a more correct gamma of 2.2,
which approximates sRGB.

The only issue with these last two examples are that dlights aren't added
linearly, since they are still performed as a straight add to a non-linear
framebuffer. To fix this, these settings are possible:

r_materialGamma 2.2
r_lightGamma 2.2
r_framebufferGamma 1.0
r_tonemapGamma 2.2

But these cause UI draws to have the wrong gamma, as these are rendered after
tonemapping. I recommend the use of the second or third set of settings.


-------------------------------------------------------------------------------
THANKS
-------------------------------------------------------------------------------
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