DXF Settings

1. Scale Export. Cave survey data often deals with very large numbers. For example, a cave can be thousands of meters or feet in length; and, with UTM coordinates, the numbers can be even larger. Programs like AutoCad have the capability of dealing with a wide range of numbers. For example, AutoCad can be used to design skyscrapers as well as tiny machine parts. As a result, AutoCad will actually do all its work in the original units. This means that if AutoCad is working with tiny machine parts, the coordinates can be in millimeters and if it is working with skyscrapers, the coordinates can be in thousands of meters. For this reason, programs like AutoCad have no problem dealing with cave data.

Some drawing programs work differently from AutoCad in that they are specifically designed to draw small objects and they are tied to paper coordinates. As a result, the size of the object they expect is no more than a few centimeters, the size of a normal sheet of paper. If you try to export a cave that has coordinates of the thousands of meters, the program will have problems. As a result, the Viewer gives you the option of scaling the outgoing DXF file.

To scale the DXF file, you enable the “Scale Export” option and choose a “Scale Factor.” The scale is set as a percentage of the original size. For example, if you select a scaling factor of 50%, the cave will be half its original size. In other words, a 10 meters passage would be scaled to 5 meters. With some drawing programs you may have to scale the cave to 0.01% of its original size before the file can be imported. When you enable scaling, all objects such as station labels and scale bars are also scaled.

2. Scale Bar Length. This option controls the length of the Scale Bar in the DXF file. The length of the scale bar will be in feet or meters depending on the current units setting.

3. Mark Size. This option controls the radius of the Station Mark. The length of the scale bar will be in feet or meters depending on the current units setting.