Change the color of the caustics postFX in script

Torque 3D 3.0 comes with a nice shader that shows the caustics effect, but unfortunately it uses the color of the textures used to generate this effect. With this resource you are able to change the color of the effect in TorqueScript. The changes are minimal, so let's go and add this nice feature to a very nice effect.

First, we add a few lines to the shader causticsP.hlsl. You can find this file in shaders\common\caustics in your project folder.

Add the marked lines:

uniform float3    eyePosWorld;
uniform float4    rtParams0;
uniform float4    waterFogPlane;
uniform float     accumTime;
uniform float4    colorize;//<=========== Add this line

float4 main( PFXVertToPix IN, 
             uniform sampler2D prepassTex :register(S0),
             uniform sampler2D causticsTex0 :register(S1),
             uniform sampler2D causticsTex1 :register(S2),
             uniform float2 targetSize : register(C0) ) : COLOR
.
.
.
   //Sample caustics texture   
   float4 caustics = tex2D(causticsTex0, causticsUV0);   
   caustics *= tex2D(causticsTex1, causticsUV1);
   caustics *= colorize;//<============= Add this line
   
   //Use normal Z to modulate caustics

Save this file.

Now we add some lines to caustics.cs which you can find in the core\scripts\client\postFx in your project folder.

// this effects the timing of the animation -

$CausticsPFX::refTime = getSimTime();
$CausticsPFX::color = "1.0 1.0 1.0 1.0";//<=========== Add this line, 1 1 1 1 give no colorization

function CausticsPFX::setShaderConsts(%this)
{
   //echo($Sim::time - %this.timeStart);
   //echo(%this.timeConst);
   %this.setShaderConst( "$refTime", $CausticsPFX::refTime ); 
   %this.setShaderConst( "$colorize", $CausticsPFX::color );//<============== Add this line
}

Now it is possible to change the color of the effect in script by changing the value of the global $CausticsPFX::color as shown below.

$CausticsPFX::color = "1.0 0.7 1.0 1.0";// red green blue alpha

The value for the alpha component is arbitrary.

Now to see it working watch the vid (I suggest the HD quality):


Have fun.

Richard.
Edit: fixed typo's.