DXF File Contents

The DXF file created has a brief header section, followed by the TABLES section, which defines text styles and line types, and the ENTITIES section, which contains the drawing data. The DXF BLOCK section is not used.

The HEADER section contains two comments, giving file creator's name and the time/date of creation. The only other variables set are $LIMMIN and $LIMMAX (the limits of the drawing Sheet), $LTSCALE and $DIMSCALE.

The TABLES section defines all required text styles and line types. Two sets of text styles are available corresponding to horizontal and vertical text (paths Right and Down), and both assume the existence of font files fnnnnnnnnnn (where nnnnnnnnnn denotes a ten-digit number) that correspond to the fonts used in a Draft session. The line types are the standard Draft predefined set; they have been given names for AutoCAD use, which are the Draft names, prefixed by ‘GT’, for example, GTSOLID, GTDOT

• Lines are passed as POLYLINE entities consisting of two or more points. The available linestyles have names prefixed by ‘GT’.

• Line thicknesses are available. See User-Defined Line Styles.

• Arcs/Circles are currently passed as POLYLINE entities with bulge factors.

• All text strings are passed as TEXT entities in the appropriate font. For example, text in Font 21 is output in style HTX21. The corresponding set of font files is defined in the TABLES section of the DXF file. Text height and shear are supported. All text is justified to the bottom-left corner of the text string. Note that non-zero character spacing is not supported in DXF output.

  AutoCAD font files are provided as part of the AutoDRAFT software. Instructions for installing these can be found in the PDMS and Associated Products Installation Guide.

• Layers are assigned to entities according to their colour definition within Draft. These layers are named GT_n, where n is a number that corresponds to a Marine colour.

• Colours are maintained according to Layer (that means, BYLAYER in AutoCAD). Note that the Layer colour for all Draft layers is white.

The ENTITIES section then follows, and is normally closed by the standard AutoCAD EOF.