Golden Rule 6 : Build to Theoretical Edges

'Theoretical' simply means the sharp intersection between primary surfaces, before a fillet or blend is applied.

When sketching we over-draw the main shapes to get a strong, taut line. If we tried to draw the main shapes and the blends in one pencil stroke, the line would be less confident and have less tension.

Theoretical edges on a sketch

The same principle applies to building Alias curves and surfaces. Build the Primary Surfaces to sharp edges, or 'theoreticals', before adding any fillets, blends or details. The result will be amore disciplined, controlled shape which will be easier to modify during design and later in engineering.

Explanation of a 'Theoretical' edge

Explore Further