I had originally posed this question here viewtopic.php?f=8&t=2135&p=40939#p40939 under Tip of the Day, Support Analysis, but after not receiving any responses, I thought it might be better to create a new topic.
I've had this question nagging at me for a while: Which has higher priority, the Upper Vertical Separator or the Horizontal Offset from Part? See my diagram:
When the part has a curved bottom, will the Upper Vertical Separation Layer (UVSL) supercede the Horizontal Offset (HO), or is it the other way around? If the Horizontal Offset is given the higher priority, then the vertical distance between the object and supports is almost doubled at the steeper parts of the object (if the horizontal offset is set a recommended parameters).
I would expect the S3D Devs to give the UVSL the greater priority over the HO, but I recently had a print where I had a large HO (about 1.5mm) and the supports were nowhere close to touching the bottom of the object at the steeper inclines.
Yes, when the part has an incline high enough, it will no longer need supports. But if the HO is increased for easier part separation (esp. for materials that are stringy), it can affect contact for even the less inclined points of the part's base.