Grids > Relax Grids relaxes the grid structure to help achieve a smoother NURBS surface. This might help capture more surface detail if, for example, grids are not already small enough or patches are too large.
Relaxation types - Pick one.
• On Surface radio button - ensures all grid vertices are kept on the surface of the polygon object. Although the grids are moved during relaxation, this option helps maintain a close approximation to the original point set data.
• With Projection radio button - projects grid lines onto the polygon surface.
• In Space radio button - moves the grid vertices normal to (toward or away from) the surface to achieve a smoother grid. This often produces the best results. The resulting grid is purple to remind you that is is a space grid.
• With Tolerance radio button and Tolerance decimal field - is similar to In Space, but lets you to specify a tolerance that limits the distance a grid vertex can be moved relative to the surface. The resulting grid is purple to remind you that it is a space grid.
• Reconstruct radio button - regenerates the grid within one or more selected patches, using an algorithm that is different than Grids > Construct Grids and which might give better results. Click one patch, Ctrl-Click additional patches, then press Apply.
OK button - saves the relaxed grids to the object in the Model Manager and closes the dialog.
Cancel button - terminates the dialog without saving changes to the object.
Apply button - performs the relaxation and leaves the dialog open for further relaxation.
A space grid is a grid that might have space between itself and the polygon surface. A space grid is purple. A space grid can exist in addition to the blue “regular” grid from which it was derived. NURBS > Fit Surfaces) operates on a space grid if it exists, or on the regular grid if no space grid exists. See Grids > Remove > Space Grids.