Thanks (again) for your help with this Martin. Apparently there really is something going on behind the scenes with the Trim function. I have no idea at all what Rhino’s Shrink command is or does, but it must be something because it does give significantly different results when I feed it’s output to Sporph and SrfMorph.
When I use Sporph Rhino displays the original set of biscuits to me morphed.
Needless to say I have no idea why. Switching Sporph’s input to my original Trimmed surface gives this result:
which is exactly what I want, except of course the biscuits cover the entire surface, not just the trimmed piece.
Note that both the above images resulted from keeping Sporph’s inputs all the same except for the target surface.
SrfMorph is different. When I give it your Shrinked surface I get this:
This is also correct except of course the biscuits are not wrapped all the way around the surface. I tried fixing that by increasing the U and/or V domains from (0, 1) to something like (0, 1.1) but that really messed up the resulting geometry. Obviously I don’t understand why (0,1) doesn’t work.
If I substitute my trimmed surface for yours SrfMorph gives me this:
Again, this is almost OK except the wrap doesn’t go all the way around and it covers the entire Loft, not just the trimmed part.
If I use a surface of revolution I get perfect results:
So after that I wanted to switch to a Loft surface which would produce a more interesting result.
It looks like I’m close to resolving this, but not quite there yet. I don’t mean to take up your time - I reckon you have a real job whereas I just do this as a hobby, but I get disturbed when things don’t work like they should.