Generate patch on a mesh

The main command to create surface patches is Generate Patches. This command is very powerful because it drives you directly from a set of polylines to the set of patches.

You can launch the command by selecting a network (polylines, set of polylines, BSpline, etc.) and a mesh.

Select the mesh and all the polylines from the folder Contour group. Then launch the "Generate Patches" command.

At startup, the command will automatically processes a set of operations to give a first result.

Lines of the network are approximated by BSpline curves with an automatic tolerance (by default the software tries to find the best compromise between accuracy and smoothness).

Patches are created from the curve network and fitted on the mesh. Hide the input mesh.

Each time the computation has finished, information regarding the standard and maximum error deviations will be outputted to give an idea about the overall accuracy of the CAD model:

• Deviation between the mesh and CAD faces

• Deviation between the input lines and the corresponding CAD curves

If you want to locally adjust curve approximations, you can select a single curve and edit the slider value (deviation values changes in the dialog box).
The new curve will be automatically recomputed and displayed in the 3D scene.

Then the next computation will only occur on CAD faces having their borders modified.

Feel free to reproduce the network using the commands listed above. In the CAD group, there are 5 contours of holes that you can reconstruct on the CAD model. See the next exercise Make holes / restriction on surfaces