The mesh may suffer discontinuities if the surfaces are not well defined. The only way to fix this is to rebuild the surfaces to force continuity.
Figure: Mesh discontinuities
First step is extract the edge of the surfaces that we are going to rebuild. Select the surfaces and click on 'Geometry -> Curve -> From Surface -> Edges'.
Figure: Extract edges to rebuild surfaces.
Now, we can remove the surface. Select the surface and type 'delete' command.
Figure: Remove surfaces.
Check and connect edge curves. You can use ‘surfaceEdges’, ‘connectCurves’, ‘splitCurves’, ‘rebuildCurve’ or ‘curveInterpolation’ to obtain the edges of the surface and the curves with same degree and same number of control points in u and v direction.
Figure: Check and rebuild curves.
In this case, we move the last control point of each curve and check its connection. To check if a curve is connected to another we can select the two curves and use the 'connectCurves' command. If the command output is '# Invalid user input: The selected curves must be connected' the curves are not well connected.
Figure: Check connection.
We can reconnect the curves by moving their control points. First, we will select the curve and show its control points.
Figure: Show Control Points.
You can zoom in using the 'Zoom Selected' option. Change the pick mode to 'PICK_OBJECT_END' and drag the selected control point.
Figure: Move Control Points.
The curves are connected.
You can construct surfaces from curves using the commands ‘extrude’, ‘planarSurface’, ‘skinned’, ‘sweep’, ‘pipe’, ‘coons’. In this example we will use the coons command to construct a surface from its contour curves.
Click on ‘Geometry->Surface->From Curves->From Edges (Coons)’ menu. Select Edge curves and press ‘Enter’.
Figure: Coons surface