Problem with imported contour lines

I imported contours from a survey in a DWG format. I use VectorWorks. In the VWX drawing the contours are polylines. I convert the VWX drawing into a DWG and then import the DWG into Sketchup 2015 but the lines are segmented into thousands of little lines. I have looked for a way, in Sketchup, to connect each contour line into one polyline, or “compose” them, but I cannot figure out how to do that. This is essential to using the SandBox tool. Does anyone have any advice?

I don’t have experience myself, but there are “weld” extensions which join line segments.

A search on this forum should yield more detail.

Thanks. I’ll check that out.

I recently did a site plan by tracing contours in PowerCADD as Bezier curves which translated into SU as many segments of lines. I don’t recall ever needing to weld them to use sandbox tools. Is it a question of selecting the string of lines? If they don’t cross other lines, triple clicking will select all the connected line segments that make up a contour. The trick is exporting contours that don’t touch or cross any other lines, at least within their context.

Opening groups, and triple clicking on individual contours:

Thanks for the correction.

Sweet. I’ll give it at try. Thanks.