I am working with an existing DEM of a river and its surrounding area in QGIS (actually a virtual raster from four separate DEM TIF tiles).
My goal is to add a bridge's profile to the DEM. I have a point cloud (.las) of the area, and from that, have extracted the bridge's area using Cloud Compare using the clipping tool:
When I rasterize the bridge (in Cloud Compare), it also creates an elevation model around the bridge, and appears to assign it at sea-level. When I bring the bridge raster and the DEM into QGIS the bridge raster includes the sea-level generated elevation (outlined in red):
So my question is, how do I extract just the bridge and insert it into the existing DEM?
I mean, I guess I could just rebuild the entire DEM since I have the LAS files and include the bridge elevation, but this doesn't seem like it should be that hard. (having said that, I have spent the morning banging my head against this).