Yeah it works with verts, edges, and faces with box, lasso, and circle select. There’s some options for different ways of determining what verts/edges are facing the viewport.
‘Verts of Face’ will select verts that are part of a face that has normals that point toward the viewport. This is what I will be using because I just want selection to act more like I am expecting, instead of grabbing occluded geometry
But if you care about being more technically correct for some reason, you can use ‘Vert’ instead. It will look at the normal of each vert individually rather that the face(s) it is part of. This works faster, but will result in some of the border verts not being selected because their normals are just a little outside of what is wanted
‘Edges of Face’ is the same deal
‘Edge’ doing the same thing as ‘Vert’ where you don’t get some of the border edges
Besides these options, you can decide to keep the box, lasso, and circle select tools the same, or some combination of 2 of them, or have them all different from each other. Any of the tools can be disabled entirely, either by turning them off, or not having any of the vert/edge/face options enabled. Any combination of verts, edges, and faces can be enabled and disabled as well.
You can adjust how close the alignment between the viewport and the vert/edge/face needs to be. Having at 0 should be enough on paper, but it is not, it will catch stray occluded mesh elements. I had thought 0.1 was good, but it still catches the occasional stray, so I have the default backface threshold set to 0.15. Setting it to 1.00 will mean it needs to be perfectly aligned with the viewport. There is an interesting aspect of this regarding quad view. Quad view should show you the exact top, front, and right side of a mesh, but even with a cube it will not think it aligned until you set your backface threshold to 0.99 or lower. But if you just align your viewport using the numpad keys (num1 for front, etc) there is no such limitation, threshold at 1.00 and pressing num1 for front view will select these mesh elements as expected. This is all assuming a cube or similar flat surface aligned with front/top/right.
You can flip which direction it will filter out. I can’t think of a reason for this but it is there if needed. The button tells you what it is currently set to do, “Selecting Forwards” means it will not select occluded mesh elements that are facing backward. This is assuming you don’t have flipped normals and are not inside your mesh. I guess if you were inside your mesh looking outward this could be useful somehow.
A convenience feature, you can see and control which tools will use ignore backface selection from the dropdown, without needing to switch to the tool beforehand.
Another convenience feature. You can decide whether to use ignore backface selection in Near select, X-Ray select, or Both. If you also use ‘Select Through’ or ‘Auto X-Ray’ these are considered X-Ray.
Going to update the top post, and this post, with link to the latest build and some more descriptions