SUPERIMPOSING SURPAC GENERATED CONTOURS ONTO A BITMAP IMAGE 

TopoCAD allows the importing of image files (Bitmap, Jpeg, GIF and enhanced Metafiles). These imported images may be transformed for best Scale and Position by simple on-screen "digitise and transform" routines. Once scaled and positioned, these images may be used as back drops to the generated CAD data, or they may be used for on-screen digitising of any information from the images.

Images may also be moved (dragged) re-sized or flipped.

The above example shows how points, digitized along image contours, can be stored and then passed to SURPAC for contour generation. These contours (in blue) are then re-imported to TopoCAD and superimposed over the background image, to show the correlation between the generated and the image contours.

TopoCAD is able to interrogate DTM files (generated through SURPAC) in order to dynamically compute and display the Z-component (height) of any sheet position covered by the DTM. Any sheet item such as Lines, Arcs, Text etc. may be heighted from a DTM by using one-off, global commands.

TopoCAD sheet information may also be exported as Bitmap images as well as the DXF and HPGL formats.