View source for FE Mesh Quality Visualization Visualization

This topic of the FE project involves generating visuals using VTK that show the quality of individual elements in a Finite Element mesh.  Generally, boundary elements are of lower quality than internal elements due to geometric constraints.  It speeds up the mesh generation process if quick visualizations are constructed to provide element quality feedback in advance of importing the mesh into the FE simulation package. 

# Mesh Quality Filter

Visualizations utilize the vtkMeshQuality filter to evaluate mesh elements.  We plan to extend the current mesh quality algorithms to add more tests for Hexahedral mesh element types in the future. 

## Rendering Techniques

The mesh quality filter adds float point "quality" values to each VTK cell in the mesh dataset.  There is a one-to-one correspondence between mesh elements and cells in a vtkUnstructuredGrid object.   Several techniques are planned, including dynamic element sizing and thresholding elements above an adjustable quality value.