Tone mapping for LE3

[YouGroove]

Let's start witha good article showing HDR and tone mapping :

 

http://frictionalgames.blogspot.fr/2012/09/tech-feature-hdr-lightning.html

 

Code from Uncharted 2 tone mapping , before trying to port it to LE3 :

 

float A = 0.15;

float B = 0.50;

float C = 0.10;

float D = 0.20;

float E = 0.02;

float F = 0.30;

float W = 11.2;

 

float3 Uncharted2Tonemap(float3 x)

{

return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;

}

 

float4 ps_main( float2 texCoord : TEXCOORD0 ) : COLOR

{

float3 texColor = tex2D(Texture0, texCoord );

texColor *= 16; // Hardcoded Exposure Adjustment

float ExposureBias = 2.0f;

float3 curr = Uncharted2Tonemap(ExposureBias*texColor);

float3 whiteScale = 1.0f/Uncharted2Tonemap(W);

float3 color = curr*whiteScale;

float3 retColor = pow(color,1/2.2);

return float4(retColor,1);

}

 

 

LE3 final working version

#version 400

uniform sampler2D texture1;
uniform bool isbackbuffer;
uniform vec2 buffersize;

out vec4 fragData0;

const float A = 0.15;
const float B = 0.50;
const float C = 0.10;
const float D = 0.20;
const float E = 0.02;
const float F = 0.30;
const float W = 11.2;	  

vec3 Uncharted2Tonemap(vec3 x)
{
return ((x*(A*x+C*B)+D*E)/(x*(A*x+B)+D*F))-E/F;
}

void main(void)
{
   vec2 icoord = vec2(gl_FragCoord.xy/buffersize);
   if (isbackbuffer) icoord.y = 1.0 - icoord.y;
   vec4 c = texture(texture1,icoord);

   vec3 texColor = c.rgb ;     
   texColor *= 3;     
   float ExposureBias = 1.3;

   vec3 curr = Uncharted2Tonemap(ExposureBias*texColor);
   vec3 Wvec =  vec3(W,W,W);
   vec3 Wtonemap =  Uncharted2Tonemap(Wvec);
   vec3 oneVec = vec3(1,1,1);
 vec3 whiteScale = oneVec / Wtonemap;
   vec3 color = curr*whiteScale;
   float powerV = 1/2.2;
   vec3 powerVal = vec3 (powerV,powerV,powerV);
   vec3 retColor = pow(color,powerVal);

   vec4 cfinal = c ;
   cfinal.rgb = retColor;

   fragData0 = cfinal ;
}

[YouGroove]

I'm progressing

 

It's not the complete shader code working , but already this make some very interesting lightening.

[YouGroove]

Let's port to LE3 a simple tone mapping shader this time :

https://github.com/pixelpusher/CreativeCode/blob/master/HarmonicSineDrawingGlow/data/ToneMap.glsl

And the working LE3 version :

 

 

 

#version 400

 

uniform sampler2D texture1;

uniform bool isbackbuffer;

uniform vec2 buffersize;

 

 

 

out vec4 fragData0;

 

 

 

void main(void)

{

 

vec2 icoord = vec2(gl_FragCoord.xy/buffersize);

if (isbackbuffer) icoord.y = 1.0 - icoord.y;

vec4 c = texture(texture1,icoord);

 

float exposure = 1.5;

float bright = 1.3;

 

vec4 c2 = c ;

float Y = dot(vec4(0.30, 0.59, 0.11, 0.0), c2);

float YD = exposure * (exposure / bright + 1.0) / (exposure + 1.0);

c2 *= YD;

 

fragData0 = c2 ;

 

}

 

You must play with exposure and brightness to adjust as you want the shader.

 

Before tone mapping :

 

With tone mapping with same directionanl light values : it looks better, the colors are more vibrant

 

 

 

Another test with no ambient, low directionnal light and a spot light :

No tone mapping

 

Tone mapping with same values as before

 

 

Shader download :

http://www.leadwerks.com/werkspace/files/file/573-simple-tone-mapping/

[YouGroove]

Question :

How to force sRGB conversion in LE3 ?

if(g_useGammaDisplay)
glEnable(GL_FRAMEBUFFER_SRGB);
else
glDisable(GL_FRAMEBUFFER_SRGB);

http://www.arcsynthesis.org/gltut/Texturing/Tut16%20Free%20Gamma%20Correction.html

 

Because trying Uncharted 2 tone mapping in LE3 is heavy saturated and some guys said it could come from sRGB ? (I don't know a lot about shaders).