Question

When I run the following pixel bender code:

input image4 src; output float4 dst;  // How close of a match you want parameter float threshold <   minValue:     0.0;   maxValue:     1.0;   defaultValue: 0.4; >;  // Color you are matching against. parameter float3 color <   defaultValue: float3(1.0, 1.0, 1.0); >;  void evaluatePixel() {   float4 current = sampleNearest(src, outCoord());   dst = float4((distance(current.rgb, color) < threshold) ? 0.0 : current); } 

I got the following error message:

ERROR: (line 21): ‘:’ : wrong operand types no operation ‘:’ exists that takes a left-hand operand of type ‘const float’ and a right operand of type ‘4-component vector of float’ (or there is no acceptable conversion)

Please advice

Answer 1

From the error message, it sounds to me like Pixel Bender doesn’t support the ternary (?:) operator. Expand it out into an if-statement:

if (distance(current.rgb, color) < threshold)     dst = float4(0.0); else     dst = float4(current);