Simplifying Site Mesh

Some site surveys we get are very detailed, showing contours every foot even for very steep sections of the site. Some of these sites also have a high number of nodes associated with the original DWG file from the surveyor. In the image below, the bold gray line towards the bottom of the survey is actually the same line type/pen as the rest of the contours, but it is selected and all nodes show as gray. The nodes are so close that the line appears as a bold gray line.

Screen Shot 2015-04-20 at 11.10.39 AM

The result of this highly detailed site survey is a very high polygon count for the site model. An easy way to simplify this is to do a little editing before applying the contours. In illustrator you can open the original DWG and select simplify. If “Straight Lines” and “Show Original” are checked you will get a preview of the reduction in nodes/segments that will result from the operation. Adjust the Angle Threshold until you get a simpler but still accurate site survey.

Screen Shot 2015-04-20 at 11.14.00 AM

Next export the drawing from Illustrator back to DWG and place into the ArchiCAD worksheet as normal. A little additional drafting may be required (as is normal for any survey) to consolidate linework & make all polylines continuous. The result is a much simpler topo drawing that can be used for creating site models and for drafting 2d site plan elements.

Screen Shot 2015-04-20 at 11.18.36 AM

Notice the above image has much simpler contour lines. This image also excludes all property & setback lines. These should always be pulled from the original survey and reapplied to the revised topography to ensure all surveyed property line elements are at the original precision.


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