Hi Pilou,

> Why in your model there are crips?

That's a display artifact that can happen if you have the mesh density set to lower. With a smaller number of polygons the triangle structure can be revealed.

If you want to eliminate those, go to Options / View / Meshing parameters, and check the "Add detail to inflections" option, which will create a denser mesh and should eliminate the visible triangles there - does that solve the problem for you?

Basically though that is not really any defect in the surface at all, it is just a display issue only.


> Could you have shell now?

I don't think it will shell properly - there tends to be a problem with matching up corners when attempting to shell an open surface that is made up of multiple pieces that have sharp corners in them.

Shell will tend to work best when used on single surfaces that are all smooth, or it can handle corners better when you shell a closed solid. A non-solid that has corners can be problematic, there was some discussion on this previously here:
http://moi3d.com/forum/index.php?webtag=MOI&msg=133.11

I believe this case will run into the same issue as in that link, with the surface extensions not being done properly.

For cases like this you may need to use the Offset command to construct some individual offset surfaces to build the thickened pieces manually. Or possibly a good approach would be to use Edit/Separate to break the model into individual surfaces, and then use Shell on the separate surfaces to get some pieces to work with.

Or actually now that I think about it some more probably the best option would be to shell the original sweep surface before cutting it.


> Curious in my model I have a more thickness of lines?? I don't know why?

Probably you've got some duplicated pieces there, or duplicated some of the edge curves as new separate curve objects.

When you have several curve objects stacked on top of each other they will get a bit darker like that.

- Michael