Yes. If a boolean operation would result in a vertex being inserted in the middle of a polygon, which would in return result in an ngon, Zbrush must insert geometry to force quads and tris at the join. An ngon can never exist in Zbrush at any time.
Actually, masking will not protect geometry from being sliced. You must make use of Zbrush’s mesh visibility functions to hide any geometry you want to protect from slicing/re-polygrouping. Never slice over the edge of a hidden polygon, however. This will split that edge, and cause zbrush to insert geometry there that will be difficult to detect once everything is unhidden, but will likely cause problems at that area when smoothing.
This is simply another limitation of Zbrush. At this time it cannot extrude 2d geometry from an edge into empty space without connecting it to something else. This doesn’t work with transpose extrusion either. I can imagine situations where this would create geometry that Zbrush wouldn’t understand. You can connect two edges along an upon hole with the Edge > Bridge command.
Remember, Zbrush ideally wants everything to be a closed volume, preferably made of quads–this is what it understands best. From a design standpoint, the developers are always working towards ways to free users from having to be overly concerned with micro geometry at the vertex level, trying to let users focus on artistry rather than technical work whenever possible. Keeping those in mind, you get a sense of when you will be using Zbrush to its strengths, and when you might want a different tool if you’ve got a lot of a specific type of work to do.
I apologize. It wasn’t my intention to hijack your showcase thread, but you seem to be inviting discussion on certain matters.
