Surfaces

The surface reference can either be a number or a name.

<surface>::= SURF = <surf_no> | <surf_name>

<surf_no>::= <integer>

<surf_name>::= <name>

The number is 1 for the main hull and -1 for the default deck surface if any. For additional surfaces the numbers are the ones used when defining supplementary surfaces during initiation of CGDB.

The names are the surface object names like "SURF='AAHULL'".

Limits can be given along the principal axes to trim the curve resulting from the surface reference. This is necessary for example, when the curve consists of multiple contours as a boundary limit curve should have only one contour.

<limits>::= [XMIN = <coord>]
            [,XMAX = <coord>]
            [,YMIN = <coord>]
            [,YMAX = <coord>]
            [,ZMIN = <coord>]
            [,ZMAX = <coord>]

If none of the keywords above are given "YMIN=0" is assumed for a symmetric surface. When referring the reflected surface the keywords above should be given relative to the original position.

This means that the surface will be intersected with the plane of the panel considering the currently set limitations. Any mirroring will take place on the resulting intersection curve.

Thus, if an inclined deck on starboard is described on starboard the limits should be set for an intersection on starboard.

Example:

PAN, ..., SB, ORI=FR50, 0, 10000, UAX=FR51, 0, 1000

          VAX=FR50, 5000, 9900,...

The first boundary statement below will give an unwanted result, the second the expected one.

(BOU, SURF= '...', REFL/.....;)

 BOU, SURF= '...', YMIN=-15000, YMAX=0/.....;

If Shell Plate Compensation is active, then two curves will result from the intersection.

In some cases, it might be convenient, explicitly to select the curve to be used. This is done by defining the side as one of the main directions of the ship.

<side_info>::= SID= AFT |

                    FOR |

                     SB |

                     PS |

                    TOP |

                    BOT