Hi Simon, it's best to form the cap by an intersection with another surface which is what Pilou is showing above.
Even if you are modeling things "patch by patch" there are still many situations where you want to make extended surfaces that then get trimmed with each other rather than trying to literally build every single surface all by itself from non-planar curves.
So for your case here you would want to start with these 2 planar profile curves:
Extrude this one to make an extended base shape that punches through your main body and also extends past the other profile as viewed from the top:
Do boolean difference on the extrusion to cut off the end and leave the imprint of the profile:
Then you trim that and the main body with each other.
If you want to have a more complex curvy "cap" that does not have a single 2D profile curve you would build an extended cutting surface using something like sweep or loft and use that surface as the cutting object in the boolean difference. See here for some a recent examples:
http://moi3d.com/forum/index.php?webtag=MOI&msg=9281.7
http://moi3d.com/forum/index.php?webtag=MOI&msg=9264.2
Making extended surfaces with simple regular structures that then get trimmed is still a major part of NURBS modeling technique even if you're doing things at a surface level.
- Michael |
