How to merge many sufaces into a whole surface

How to merge many sufaces into a whole surface?
who could help?

We can’t. Be specific, depending on the details the process will be different, if even possible at all.


Have no ideal to simulate a whole surface below tolerance?

If you want to join the surfaces into a polysurface use the Join command. Make sure the edges are within tolerance of each other.

If you have a polysurface with planar faces then MergeFace or MergeAllFaces may be useful.

Or do you want to create a single surface from many surfaces? In some situations MergeSrf can be used to merge adjacent surfaces. In most situations rebuilding the model is required. Without seeing what the surfaces look like, or preferably a .3dm file with the geometry, it is impossible to provide more detail…

碎面.3dm (84.8 KB)

Hi,David Cockey ,I want to merge the four surfaces into a single whole one not brep , with tolerance 5mm or below ?
Can you solve this ?


If the surfaces are planar they can be merged into a trimmed single surface. Join the surfaces to create a polysurface, then MergeSrf.

If the surfaces are not planar then it is not possible to merge the five surfaces into one surface. It is probably possible to create a single trimmed surface with very similar geometry.

Thanks,David Cockey
To create a single trimmed surface with very similar geometry using Patch command?

Have anyother idea?

You should review the basics of NURBS surfaces.


Curve/Curve From Objects/Duplicate Edge. Select the outer edges of the 5 surfaces. Now you have a set of curves. Use join to create 4 segments and then select Surface/Curve Network and select your 4 segments. Enter and VIOLA. A single surface.

Can you show an example of how to obtain a valid set of input curves for NetworkSrf from a set of surface such as in the illustration?

curve network.3dm (205.3 KB)

as @davidcockey has hinted out already indirectly, untrimmed NURBS surfaces have one key limitation, they cant exceed 4 sides. your surface would have 5 if merged. that is the reason for such parts to be trimmed (patches) or further divided.

what is the need for one single surface? can it be trimmed? if not why not. if you dont tell anyting specific you will just piss everybody off trying to help you, guessing games are not helping yourself either, unless you actually enjoy it.

To merge five surfaces into one whole surface ,I just want it’s convient to OffsetCrvOnSrf

Thankyou,Stephen Thode