I have brought in a raster ASC file (X,Y,Z) and am only interested in the red area (ultimately I want to create 1m contours layer) but cannot find a way to query the data to only show the red area.
you have Civil3D, then it's easier to import the points as Civil3D-surface, then define a border to this surface (your red polyline) and set the style to show contours. The contours are also calculated with higher quality then (imho).
Good luck, - alfred -
I'll agree to disagree on this as in my experience the contour layer (obtained via MAP tools) is far better then the same contours derived via a C3D surface.
Even though "..all contours are lies..", the MAP version looks a lot better
You might be able to try:
in a text editor, manually deleting the other points outside of the extents
treat it as a point cloud (treat it as points), and this should allow for filtering out what you do not want