Cut/Fill Color Map

This command creates a cut/fill color map typically in red and blue in order to show the difference between grid or triangulation surfaces. In the options dialog, the ranges of the cut and fill zones are set along with the colors. The Automatic Colors has several colors styles to choose from for the cut to daylight to fill colors. When not using the Automatic Colors, the Cut/Fill Transition color is used for the zone between the smallest cut and smallest fill. For triangulation surfaces, the Map Subdivisions is how many times the surfaces will be divided in the X and Y directions to make cells for coloring. For example, Map Subdivisions of 50 makes 2500 colors cells from 50x50. The Limit Cut/Fill Map Range option is a way to draw the color map only for a specified range such as only showing the deep cut. The Auto Set function fills out the cut/fill ranges based on the current two surfaces. The Set By Interval function fills out the cut/fill ranges by a user-specified depth interval.

For analyzing using the grid option, you need to already have two existing grid files. If the grids are not visible in plan view, you may want to have them display on-screen using the Draw 3D Grid File command. The grids should overlap with the same location and resolution. The resulting red/blue map with legend is shown below.

No coloring is done on tin or grid cells that extend beyond the extent of the data. Extrapolation can be used to calculate elevations for the grid cells that are beyond the data limits. The prompt Extrapolate grid to full grid size? shows when there are grid cells with no elevation in a grid (.GRD) file. Extrapolation fills in all the grid cells. The method to extrapolate uses a safe calculation that tends to average out or level the extrapolated values. So extrapolated grid areas are not as accurate as grid areas within the limits of the data.

Prompts

For a color map showing differences between two grids:
Type of surface model source [Tin/<Grid>]? press T for a Triangulation (.TIN) file, or press Enter to accept default choice in brackets.
Select Base Grid File Dialog Select an existing .grd file.
Select Final Grid File Dialog Select a second existing .grd file.
Select Inclusion polyline: pick a closed inclusion perimeter
 Select Exclusion polylines (Enter for none).
 Select objects: pick exclusion polylines or press Enter
 Cut/Fill Color Map Options Dialog
Select point for color legend: pick a point
 Legend size <10.0>: press Enter
Label all zones or summary [All/<Summary>]? press Enter
Pulldown Menu Location: Surface >> Cut/Fill Utilities
Keyboard Command: cf_map
Prerequisite: Two grid (.GRD), triangulation mesh (.FLT) or tin (.TIN) files
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