Smooth surface

Hello everyone,

I would like to ask you to help me with next issue related with surface creation. I have twoo surfaces pink and yellow. See attachment.

The yellow surface is determined by green surface edges & straight lines. In this case is problem the corner of straight lines. I do not know how to created one smooth surface without visible isoline which leads from the center corner of the straight line. I would like to cut the yellow surface by plane in the final consequence bud I do not want to have visible central isoline in my cutted horizontal section. I also used all surface tools but I have not been succesfull.

I have same problem aslo in case of pink surface.

I really do not know how to solve it in this both cases.

02_PEE_Help.3dm (116.2 KB)

Hi Michal - am I correct that you do not want the structure of the pink polysurface in the top, you want a single surface? And you do not want a kink in the surface, is that right?

Maybe? 02_PEE_Help_PG.3dm (110.3 KB)


Hi Pascal, how did you do this?? This is awsome! Is it possible to do same surface also with red surface below? Can you tell me how? I will try this for red one.


Hi Michal -

  1. make a line from the mid point of the line between the green surface corners to the vertex of the V shape - the line is hidden in my file, use ShowSelected to retrieve it.
  2. Loft from one green surface edge to this line and from the other green surface edge to the same line. Style=Normal, btw. Two surfaces.
  3. MatchSrf the two surfaces to each other for Tangency with Average set and ‘Preserve other end’ set to Tangency. Set ‘Preserve icosurve direction’ in the dialog as well.
  4. MatchSrf the two for Position to the legs of the V shape.
  5. MergeSrf the two surfaces with Smooth=No


Pascal, that works! Thank you so much.

Hello Pascal,
I have one more question…I created surfaces according of your procedure. Slightly over the yellow surface is purple surface which I created by Loft tool. Because the purple surface have to be over the yellow surface so I do not understand why are left corners of yellow surface protrudes above the purple surf.

There is possible to fix that overlaping?

02_PEE_Help.3dm (117.3 KB)

Hi Michal - it does not, this is a consequence of the shaded display meshes being too coarse - see


If I adjust the mesh settings:

It looks cleaner -

You can make the display mesh even finer - like by setting ‘Minimum initial grid quads’ high, say 1024, and it should look more correct.
If you Intersect the surfaces, you’ll see they do not actually intersect except at the edges.