Offset Data

An alternative representation of the surface is through Offset Data which is analogous with the Loftbook. The particular form of this point representation that can be used is the Britfair file. The offset data is interpreted into a surface consisting of a myriad of flat triangles. This simplified representation can be used when a faired surface is not available (maybe an early design stage or due to a lack of suitable third party information being available). At a future time, if a true surface is available then this can be used to replace the Barehull of the envelope and allow regeneration of the internal arrangement to give increased accuracy of the design.

The following steps describe the use of a Offset Data to produce a surface with the intention of using it as the barehull.

1. Select FILE \ USE \ OFFSET DATA... to bring up the Use Design dialog. This dialog lists the available offset data designs for the current project. If the Britfair file is newly created and not part of the project as yet it will not be listed. Use the Import... button to locate the file and copy it to the project, then proceed to the following step.

2. Select the required Offset Data from those available, and then having set the appropriate options (Sparse, Reflect Body, Use Quadrilaterals and Reduce Edges are usual for a symmetric monohull) click Use.

   The resultant surface should be checked using an Identify Flash to check to see if any edges are highlighted. If they are the Britfair file will need to be checked, see Use of Offset Data to form a Surface in the Surface User’s Guide, and modified.