Painted FEM model
Rendering with OpenGL allows for (and very much requires for dynamic movement of the scene) more efficient edge line creation.
The new edge modes do not draw lines that are obscured by other parts of the scene. Recent versions of CAPOST could perform such 'hidden line removal', but it would take a very long time for CAPOST to determine which lines should be removed. CAPOST with OpenGL does it for you in fractions of a second.
The default edge mode is Regular Edges + Outline. This mode uses the cosine of the angle between element faces to decide whether or not an edge line should be drawn, and it also includes an OpenGL generated outline of the model (the OpenGL outline edges are shown in the 'Outline Only' image below.) Typically edge lines look best with Regular Edges + Outline mode, but you may want to choose a different mode if the edge lines do not look good.
Edge line quality is highly dependent on mesh quality, so it is possible that none of the CAPOST generated edge lines look good. For that reason, you can import edge lines from a 3D line file. Edge lines from file + outline mode combines the 3D line file with OpenGL's outline edges.
Example edge modes are shown below:
Painted FEM model
Fast Edges + Outline
Regular Edges + Outline (default)
Outline Only
Edges from Line File + Outline