Created January 2005 by Glenn Ramsey. Based on example 21h.

This example illustrates face fitting of a volume element which has collapsed nodes with mapping of the common derivative versions between the collapsed nodes.

Example 21h also demonstrates fitting with collapsed nodes but in that example the derivatives of the line connecting the two collapsed nodes are fixed and the line does not get fitted.

Figure 1. shows the initial unfitted mesh. Figure 2 shows the fitted mesh without the C0 continuity having been set (using fem define coordinates). Figure 3. shows the fitted mesh with the C0 continuity set up but without the derivative mapping defined (using fem define mapping). Figure 4. shows the element correctly fitted without mesh anomalies.

See also the comments in the com file.

Fig. 1. Initial Mesh.


RMS Error = 9.96 mm

Fig. 2. Fitted mesh without mapping for C0 continuity (set up in the .ipcoor file).

RMS Error = 1.22 mm

Fig. 3. Fitted mesh with mapping for C0 continuity but without derivative mapping.

RMS Error = 1.00 mm

Fig. 4. Fitted mesh with mapping for C0 continuity and derivatives (set up in the .ipmap file).

RMS Error = 1.20 mm