CAD surfaces, sometimes referred to as B-Reps or NURBS—Non-Uniform Rational B-Splines, are mathematically defined and have an “exact” representation. However, curved surfaces must be converted into a series of approximated flat faces to render in the graphical view. The quality of this approximation is determined by the Surface Rendering Options set here.
If you find that your curves and surfaces are not being represented accurately enough for your liking, or if you see “tearing” in your CAD surfaces, you can modify the surface rendering options.
Max Trimmed Edge Angle. Specifies the maximum length of edge segments for trimmed edges. A lower value gives a higher quality representation. Use a value of 0 to default to a low- quality setting.
Note that this setting also applies to spline curves:
Max Facet Chordal Deviation. Specifies the maximum allow- able distance between a rendered edge and the surface with which it is associated. Use a value of 0 to default to a low-quaity setting.
When laying out points on an object’s vertices, this setting affects how many points are constructed.
Max Facet Edge Length. Specifies the maximum allowable length of each edge segment.
Max Facet Aspect Ratio. Specifies the maximum aspect ratio (length vs. width) of each rendered facet.
Force Re-render of all surfaces. Checking this option will force SA to recalculate surfaces using the latest settings in the window. If unchecked, and surfaces have already been rendered, then the settings will not take effect until the file is reopened.
Draw Silhouettes in Hidden Line Removed Mode. By default silhouette's are not drawn in hidden Line Removed mode. This option allows them to be drawn.