Use the COPY_SURFACE_MIRROR operation to copy a surface.
Click on any control point of the surface you want copy.
A new surface is created, with the same control point locations with a 1 metre offset in x, y and z coordinates, followed by x-coordinate signs reversed.
Note that the orientation of the new surface is reversed (so that the normals point in the opposite direction).
Use REVERSE_SURFACE_ROWS to reverse the orientation of the new surface.
Switch between orthogonal projection views and continue mirror copying surfaces.
Click the icon again to disable the COPY_SURFACE_MIRROR mode.
|For the dedicated staff at Hammersmith Hospital.|