Inserting a photometric grid

The photometric grid is a three-click rectangular object, and can be inserted in Center-line Placement mode or Edge Placement mode. The grid can be tilted, accounting for sloped or raked stages.

1. Ensure that each lighting device contributing to the illumination has an assigned focus point; see Creating a focus point object.

To perform calculations without drawing light beams, disable Calculate Using Only Visible Beams in the photometric grid properties.

The first time you use the tool in a file, a properties dialog box opens. Set the default parameters. The parameters can be edited later from the Object Info palette.

Parameter	Description
Rotation	Specifies the number of degrees to rotate the object (0.00 is horizontal)
Text Style	Select a text style from a library or the current file. To use the style defined for the object’s class, select <Class Text Style>. To format the text using options on the Text menu, select <Un-Styled>. See Using text styles and Formatting text.
Show Elevation	Displays the grid elevation along with the photometric values
Show Zero	Displays elevation values of zero
Show 3D Labels	Displays photometric labels in 3D views, along the plane created by the grid
Calculate Using Only Visible Beams	Determines the photometric values based on only the lighting devices with Draw Beam selected; this reduces calculation time
Use Threshold Settings	Displays each photometer in the grid according to a color that corresponds to the specified threshold ranges
Grid Spacing X	Specifies the spacing of photometric values in the X direction
Grid Spacing Y	Specifies the spacing of photometric values in the Y direction
Grid Width X	Specifies the length of the grid in the X direction; available in Object Info palette only
Grid Width Y	Specifies the length of the grid in the Y direction
Slope Based On	To tilt the grid, select whether to specify slope values by angle or offset distance coordinates, and enter the angles or offset distances
Tilt Angle X/Y	When the grid slope is based on angle, specify the slope angle in the X and Y direction. If specified by distance, the calculated angles display.
Height Offset X/Y	When the grid slope is based on distance, specify the total height offset in the X and Y direction. If specified by angle, the calculated offsets display.
Threshold Settings	Opens the Threshold Settings dialog box, to specify the threshold values and the colors for the threshold ranges
Refresh	Refreshes the grid display after changes have been made to the lighting conditions

After placing the photometric grid, set the grid’s Z value from the Object Info palette; illumination values vary depending on the grid’s elevation.

Mode	Description
Center-line Placement	Click once, and then again, to define the length through the center of the grid. Click again to specify the grid width.
Edge Placement	Click once, and then again, to define the length along the edge of the grid. Click again to specify the grid width.
Preferences	Sets the default preferences for the photometric grid