Volumes By Layers

This is the easiest yet still equally accurate method for calculating volumes. For this command, volumes are calculated in one step by a simple window of the area, selecting the items, and calculate.

First, you must specify the grid location and resolution. The grid location should enclose the area for volume calculations. Next the program asks for the layer names of the entities for the base and final surfaces. You designate the layers to use for each surface either by typing the layer names or by picking from the screen, then during the routine you select the entities to use. You may safely use the keyword ALL to select the entities, since you have pre-defined the layers to use, and all those entities not on the specified layers will be filtered out. These entities, for use in modeling the surfaces, can be points, lines (such as triangulation lines), 2D polylines (such as contours), and 3D polylines (such as breaklines).

Inclusion and exclusion perimeters may optionally be specified to limit the volume calculation area on the grid. An inclusion perimeter should be used if there is a closed polyline for the limit of the disturbed area. Then the program internally generates grids of the surfaces from the entities on the corresponding layers and then calculates and reports the volume. The main disadvantage to this routine is that it doesn't have the special output options of Two Grid Surface Volumes such as Depth Contours.

Prompts

Command: layervol
Pick Lower Left limit of surface area: pick lower left corner of grid
Pick Upper Right limit of surface area: pick upper right corner of grid

You are then prompted to designate layers:

Press Select Layers from Screen to show the routine which layers to use by selecting sample objects from those layers.

Select entities on layers of Existing surface. select sample object(s)
Select objects: Specify opposite corner: 3 found
Select objects: press Enter to conclude selection.
Select entities on layers of Final surface. select sample object(s)
Select objects: Specify opposite corner: 10 found
Select objects: press Enter to conclude selection.
Reading points ...
Select surface entities on corresponding layers.
Select objects: all filters out those objects not on designated layers
85 found
Select objects: press Enter to conclude selection.
Reading points ... 9396
Assigning grid values> 5300
Pass> 28 Null Z values left> 0
Writing grid file: C:\Documents and Settings\. . .\USER\grid1.grd
Assigning grid values> 5300
Pass> 43 Null Z values left> 0
Writing grid file: C:\Documents and Settings\. . .\USER\grid2.grd
Select the Inclusion perimeter polylines or ENTER for none: select inclusion perimeter
Select objects: 1 found
Select objects: press Enter to conclude selection.
Select the Exclusion perimeter polylines or ENTER for none.
Select objects: press Enter for none.
Reading cell> 5346
Pass> 28 Null Z values left> 0
Reading cell> 5346
Pass> 43 Null Z values left> 0
Pre-processing grid cells ....
Processing cells ...
Select point for color legend (Enter for None): press Enter

Pulldown Menu Location: Surface >> Volumes By Grid Surfaces
Keyboard Command: layervol
Prerequisite: Entities that define both the base and final surfaces.