fade = 0.2; // fade duration in seconds
fadeIn = (time - inPoint) / fade;
fadeOut = (outPoint - time) / fade;
if (time < inPoint + fade) {
    ease(fadeIn, 0, 1) * value;
} else if (time > outPoint - fade) {
    ease(fadeOut, 0, 1) * value;
} else {
    value;
}