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//  Layer Auto-Fade:
//  http://provideocoalition.com/pvcexclusive/story/expression_shorts_-_auto_fade_layer

fadeTime = 10;
opacityMin = 0;
opacityMax = 100;
layerDuration = outPoint - inPoint;
singleFrame = thisComp.frameDuration;
animateIn = linear(time, inPoint, (inPoint + framesToTime(fadeTime)), opacityMin, opacityMax);
animateOut = linear(time, (outPoint - framesToTime(fadeTime+1)), (outPoint-singleFrame), opacityMax, opacityMin);

if(time < (layerDuration/2+inPoint)){
	animateIn;
}else {
	animateOut;
}