Hi Burr, well one of the reasons there is that "auto place" mode for sweep where you can draw stuff off to the side and flat on the plane is because it can be inconvenient to create stuff directly in place on the rail if the rail is just freely bending around in space.

Here's an example - you can take these curves drawn flat on the plane:



Then when doing a sweep the "auto place" mode will automatically move and rotate those curves into different stations along that curve, to make this result:



So that's performing some movement and rotation steps that would be kind of inconvenient to do manually.


But from what you are describing where the boolean direction would come from the viewport, it is not very difficult to make the curve copies for that case - you can use the Transform > Copy command to place several with clicks, or use the array tools to make some kind of pattern arrangement.

So because it's not so difficult to get curves arranged in just a 2D pattern, having some kind of custom step in booleans to do something like that would not really be delivering a whole lot that you couldn't already get done easily. The downside to adding a lot of extra special case stuff to any particular command is that it increases the complexity of the command, just incrementally making things more difficult to use...

One thing that I do want to add to booleans though is an option to limit the depth of the automatic extruded shapes so that you could specify how deep the hole should be instead of it only going all the way through the object... I think this would have some good potential to save a lot of manual steps for making indentations onto curved surfaces which can take several steps to do right now.

But it's a bit harder to justify adding in some special function to the booleans if you can already get the same job done with about the same number of clicks using existing tools - so like for example with an "auto place" boolean that used the view direction just using the Transform > Copy command to copy your cutting curve first before doing the boolean gives you that same kind of a thing...

- Michael