syntax/opcodes/pitcheg_release_shape

0 is linear, positive values are slower curves (that means the envelope will initially not fade out much, and most of the fade will happen towards the end of the release period) and negative values faster (quick initial fadeout with quiet tail fading out more slowly). Past 10 or -10, there's little difference - at that point, the envelope is practically a horizontal line and a vertical line (if positive) or a vertical line followed by a horizontal line (if negative).

Examples

ampeg_release_shape=2.1
ampeg_release_shape=-3.8