Understanding evalscript/V3 structure in custom scripts

Hi Forum,

I am trying to get my head around the way evalscripts work by converting a simple script to follow the V3 evalscript structure. So if I have the following script functioning in EO Browser:

let kndvi = Math.tanh(Math.pow(((B08 - B04) / (B08 + B04)), 2));



//Visualization, as used in EO Browser:

if (kndvi<-1.1) return [0,0,0];

else if (kndvi<-0.2) return [0.75,0.75,0.75];

else if (kndvi<-0.1) return [0.86,0.86,0.86];

else if (kndvi<0) return [1,1,0.88];

else if (kndvi<0.025) return [1,0.98,0.8];

else if (kndvi<0.05) return [0.93,0.91,0.71];

else if (kndvi<0.075) return [0.87,0.85,0.61];

else if (kndvi<0.1) return [0.8,0.78,0.51];

else if (kndvi<0.125) return [0.74,0.72,0.42];

else if (kndvi<0.15) return [0.69,0.76,0.38];

else if (kndvi<0.175) return [0.64,0.8,0.35];

else if (kndvi<0.2) return [0.57,0.75,0.32];

else if (kndvi<0.25) return [0.5,0.7,0.28];

else if (kndvi<0.3) return [0.44,0.64,0.25];

else if (kndvi<0.35) return [0.38,0.59,0.21];

else if (kndvi<0.4) return [0.31,0.54,0.18];

else if (kndvi<0.45) return [0.25,0.49,0.14];

else if (kndvi<0.5) return [0.19,0.43,0.11];

else if (kndvi<0.55) return [0.13,0.38,0.07];

else if (kndvi<0.6) return [0.06,0.33,0.04];

else return [0,0.27,0];

And I am trying to reorganize it to work with the evalscript structure of “setup” and “evaluatepixel” like this:

//VERSION=3

function setup() {

  return {

    input:  "B04", "B08"],

    output: { bands: 3 }

  };

}



function evaluatePixel(sample) {

let kndvi = Math.tanh(Math.pow((sample.B08 - sample.B04) / (sample.B08 + sample.B04)), 2);

if (kndvi<-1.1) return  0,0,0];

else if (kndvi<-0.2) return  0.75,0.75,0.75];

else if (kndvi<-0.1) return  0.86,0.86,0.86];

else if (kndvi<0) return  1,1,0.88];

else if (kndvi<0.025) return  1,0.98,0.8];

else if (kndvi<0.05) return  0.93,0.91,0.71];

else if (kndvi<0.075) return  0.87,0.85,0.61];

else if (kndvi<0.1) return  0.8,0.78,0.51];

else if (kndvi<0.125) return  0.74,0.72,0.42];

else if (kndvi<0.15) return  0.69,0.76,0.38];

else if (kndvi<0.175) return  0.64,0.8,0.35];

else if (kndvi<0.2) return  0.57,0.75,0.32];

else if (kndvi<0.25) return  0.5,0.7,0.28];

else if (kndvi<0.3) return  0.44,0.64,0.25];

else if (kndvi<0.35) return  0.38,0.59,0.21];

else if (kndvi<0.4) return  0.31,0.54,0.18];

else if (kndvi<0.45) return  0.25,0.49,0.14];

else if (kndvi<0.5) return  0.19,0.43,0.11];

else if (kndvi<0.55) return  0.13,0.38,0.07];

else if (kndvi<0.6) return  0.06,0.33,0.04];

else return  0,0.27,0];

}

The first version gives a nice visualization in various shades of green, eg https://sentinelshare.page.link/zhxG ; the second version returns no error message but all pixels in black: https://sentinelshare.page.link/bXSL.

What am I doing wrong?