Ogre 3D 1.7

Time for action — selecting a color channel

We are going to use the previous code, but we have to add and delete a lot:

1. Start with the fragment program. Besides the normal parameter, add a float4 uniform parameter to store the color channel factors. Use these factors to multiply the color we retrieved from the original scene texture:

   void MyFragmentShader10(float2 uv : TEXCOORD0,
   out float4 color : COLOR,
   uniform sampler2D texture,
   uniform float4 factors
   )
   {
   color = tex2D(texture, uv);
   color *= factors;
   }
   

2. Create a new material that uses the fragment shader and add the parameter with the default value of (1,1,1,0). This means that without changing the parameter, the scene will be rendered normally:

   fragment_program MyFragmentShader10 cg { source ...