Hi Scott - making shapes in a separate "patch by patch" method like that will tend to naturally result in shapes that have creases where they meet up. That happens because your shapes basically stop abruptly at their ending spot.
Usually to get smooth surfaces you need to instead build things in large broader pieces rather than as doing them as separate pieces.
See here for some more explanation of how building a shape that "stops" at a boundary will result in creases:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1398.18
http://moi3d.com/forum/index.php?webtag=MOI&msg=1398.19
Notice how in Burr's previous example above, the 2 separate forms for each broad shape is not made up of fragmented bits but instead one big single surface?
> even after running the Join command.
There is a major difference from how Joining works in NURBS modeling as compared to polygon modeling.
In NURBS modeling joining makes a connection between pieces but it's purely a topological connection where the system now knows how the outer skin of a solid is connected together - nothing changes in the actual geometric shape of surfaces when they are joined.
Also in a polygon modeler even if you are not doing sub-d smoothing you can merge polygons together and then they get the sort of fake smooth phong/gouraud shading applied to them to make the rendered result look like it's smooth even though it's really made up of flat polygons. That's also very different from NURBS modeling - NURBS modeling doesn't use any kind of fake shading to it at all, things will only be smooth if the surfaces that you have constructed actually are smooth to one another.
Basically with NURBS modeling you don't really want to be building things in a patch-by-patch manner like that - instead for things that are supposed to be smooth build them out of a larger single surface, and when there is a transition between broad shaped forms, don't try to build that transition directly into your surfaces, instead focus on building each broad form separately and then they will get trimmed or booleaned where they cut each other and have a transition constructed using fillet or blend.
- Michael |
