I only know the basics. The closer you are to a straight line, the less distortion. The smoother the transitions (IE using curves instead of angles) the less fuzz you get. A very basic distortion for analog warming purposes would be to just open it up, and then put an upward curve in the line to taste. That’s your analog distortion model right there, and it’s how I use it 95% of the time. Image line just has the habit of letting people do whatever with their stock plugs, and that means they usually let users go way, way farther than they need to for most common use cases.
BTW, the default view is mirrored, so you don’t see the negative polarity of the transfer function, but it’s a mirrored copy of what you’re doing on top. If you flip that switch at the bottom, you can edit the negative and positive polarities of the transfer function separately, which is what I do to filter away one polarity of the signal. Then you put a flat line in the middle for either the negative polarity on the left or the positive on the right, which just makes any input on that side go to zero.
@bfk The only difference between compression and distortion is the attack/release a compressor gives. Think about it, if you put a signal into distortion, like the waveshaper, you change the output level for a given input infinitely fast based on the function you define in the window. A compressor changes the output level for a given input level based on the threshold and ratio settings as fast as the attack and release allow. That’s why, when you’re compressing bass, you have to back way off the attack and release so that the compressor can’t change level too fast and cause distortion. If the compressor changes gain faster than the wave changes level, it modifies the wave shape instead of the volume of the wave, and that’s distortion.