Architectural and survey drafters working in the USA will often deliver CAD drawings to landscape designers in a file format called dwg that’s used by AutoCAD software. CAD drawings developed in AutoCAD (like they are in gCADPlus) are constructed full-size in model space. Both software applications make their drawings in units and drawings from architects in the USA use inches as the base unit whereas gCADPlus uses decimal feet as the base unit.
So we work in decimal feet and you may well be provided with a drawing of a site including some plans for a new building and be asked to develop a set of landscape plans using gCADPlus. Some scaling will be required in order to work a drawing from the Imperial environment in gCADPlus.
- We recommend the first step in working with a drawing such as this is to convert the AutoCAD dwg file into a DXF file. Since architects often use a variety of software applications to speed their design work and the dwg file can contain remnants of those applications, we believe that since DXF is an open and published standard, and opens directly in gCADPlus it’s the best format to use.
Tip: Converting a dwg to DXF is best done with the free ODA tool.
2. Since gCADPlus when being used with a drawing created in the USA Imperial environment use base units in inches, the second step in the conversion process is to scale the incoming drawing by an appropriate factor. Since there are 12 inches in a foot, we need to scale everything in the drawing by a factor of 1/12 i.e. 0.083333. Note that the factor is not a whole number it’s a recurring number. We usually set the scale to 6 decimal places, but you might want a higher level of accuracy and add more decimal places. After loading the DXF file, turn on all layers, select everything in the drawing, and apply the scale.
3. The third step is to check that dimensions are displayed in a style that suits the Imperial system. Even though the converted design is now drawn in decimal feet, your American clients will expect that dimensions are displayed in feet and inches. For reassurance that the conversion process has gone well, it is a good idea to apply a dimension on an object of known size
This movie shows how to apply linear and aligned dimensions to a landscape drawing. We make adjustments to text location, offset from dimension origin, etc. We show how to control the display of dimensions in the USA environment where there is a need to display a dimension in both feet and inches.
Click here to download a block that contains the dimension style used for Imperial dimensioning shown here. Insert the block into your drawing and the Imperial dimension style is then available.
This movie shows how to manipulate dimension style settings for a style called architectural in a design for a courtyard. We adjust the round-off unit setting to give the correct display of feet and inches. In addition, here is a small tip showing how to synchronize the direction of the mouse wheel if you use gCADPlus in both Windows and Mac environments.
Here is another movie that shows how to adjust dimension styles.
TrueView
Autodesk has made freely available an application called TrueView that allows users to open DWG files, check the status of settings in the drawing or convert them to work with older versions of AutoCAD software.