Creating a Grid Volume Surface

2012-03-14

Product Documentation

Intermediate

A grid volume surface is a difference grid surface based on user-specified base and comparison surfaces as well as grid spacing and orientation.

A grid volume surface is an approximation of the difference between the base and comparison surfaces. It is formed by making a grid from points whose Z values are the differences between the Z values of the comparison and base surfaces. Therefore, the grid volume surface gives the exact difference only at the grid points. This is true whether the comparison and base surfaces are both grid surfaces, both TIN surfaces, or one of each.

Grid volume surfaces enable you to generate a volume quickly, which is useful for iterative site design.

Note

Grid spacing has a direct correlation as to how quickly grid volumes generate.

A volume surface is a persistent surface object. Therefore, you can display cut and fill contours, cut and fill points, and add labels to it. View a volume property (cut, fill, net) of a volume surface by selecting Surface Properties. For more information, see Editing and Viewing the Surface Definition.

If you want only to query and obtain information about a surface volume or a bounded volume , use the Volumes and Bounded Volumes utilities.

To create a grid volume surface

Click Home tabCreate Ground Data panelSurfaces drop-downCreate Surface.At the Command prompt, enter CreateSurface.
In the Create Surface dialog box, in the Type list, select Grid Volume Surface.
Click to select a layer. For more information about layers, see Object Layer Dialog Box.

Note
If you do not select a layer, the surface is placed on the current layer.
In the properties grid, click the Value column for the Name property and enter a name for the surface.

Note
To name the surface, click its default name and enter a new name, or use the name template. For more information, see Name Template Dialog Box.
To change the style for the surface, click the Style property in the properties grid and click in the Value column.
The Select Surface Style dialog box is displayed. For more information, see Surface Styles and Display.
To change the render material for the surface, click the Render Material property in the properties grid and click in the Value column.
The Select Render Material dialog box is displayed. For more information, see Assigning Render Materials to Objects
Click the Base Surface property to select the base (bottom) surface. You can enter the surface name or click to open the Select Base Surface dialog box where you can select the surface in the list.

Note
Select a surface in the drawing by clicking and following the instructions at the command line.
To set the grid parameters, such as spacing and orientation, enter their values into the Values column or click to use the drawing area to derive these values.

Note
The grid spacing parameters determine how precise a surface volume is. For example, small grid spacing creates a precise volume measurement (but may increase the loading time).
Click the Comparison Surface property to select the comparison (top) surface. Enter the surface name or click to open the Select Comparison Surface dialog box where you can select the surface in the list.

Note
Select a surface in the drawing by clicking and following the instructions at the command line.
Click OK to create the surface.
The surface name is displayed under the Surfaces collection in the Prospector tree. For information about adding data to the surface, see Adding and Editing Surface Data.