Hello, I’m trying to model a seemingly simple surface but am having difficulties. Maybe someone can help me? Ideally, I’d like to build the entire surface as a connected whole. I’ve already tried using the patch tool, but the trimmed surface can no longer be mirrored, or I encounter other difficulties when trying to edit it further. I also tried assembling the surface from parts by building one section with Network Surface and then adding the upper part with Sweep2Rail. However, I’m still unable to create a clean transition (see photo). I have the same problem with the surface on the underside. I’d also like to keep the planar surface in the middle, so it should transition smoothly into the other surfaces. I’m just not sure what else to try. Could SubD be an alternative? I’d be very grateful if anyone has any ideas. Best regards, Tim
Headsupport.3dm (2.9 MB)
Cases like this are better handled by the “Blend surface” tool.
However, if you like to have a full control over the new surface, I recommend you to build new input surfaces with far less control points, because the current one is overly-complex and leads to generating adjacent surfaces with much more control points than necessary.
I’m not at home now, but in a few hours I will be back and then may capture a short video tutorial to show how I would handle such corners.
Edit: I will not be able to record a video, because the input geometry is made from network surfaces and therefore it needs a total remodeling. But as I mentioned earlier, you can simply use a “Blend surface” instead of “Sweep 2 rails” for the quickest result.
@Rhino_Bulgaria Thank you very much! I will definitely try to use less control points in the future. 
@lander Thanks for the video and the file! This is really a great help. 
Could you possibly send the video again in real time, I would like to understand exactly how you built the surface. It looks quite complicated in this video. 
Can’t upload realtime cause 20kb limit. 
I suppose I can learn how to reduce the file size other ways.
Ahh ok. If it doesn’t work, it’s no big deal. I can try to stop it again and again and understand how you worked. Thanks anyway
I played around with video quality. This one is about 17kb, so just a bit under the 20kb limit.
Let me know if it’s better than the other one lol. The quality looks bad to me but, at least it’s not like 3000% faster than realtime like the other one or something. 