AE粒子雨视频中的采样代码

教程：https://www.bilibili.com/video/BV1J54y187p7

在这里记录一下代码

源文件已经成烟

var h = 45;
var spacing = 24;
var sampleLayer = thisComp.layer("数码雨背景");
var outputText = "";
seedRandom(index,true);

for (var j=1;j<=h;j++) {
		for (var i=1;i<=w;i++){
			var samplePointX = i * spacing - (spacing /2);
			var samplePointY = j * spacing - (spacing /2);
			var sampleLightness = rgbToHsl(sampleLayer.sampleImage([samplePointX,samplePointY],[2,2],true,time))[2];
			if (sampleLightness > 0.18){
				outputText+=String.fromCharCode(Math.round(random(65,91)));
			} else {
				outputText+=" ";
			}
		}
	outputText+="\n";
}

outputText