Sight Visibility Dialog Options

You can access this tool from the following:

Ribbon: Terrain > Analysis > Sight Visibility

Settings	Description
Parameters
Lock to Start
Start	Specifies the start station for the first sight line analysis. Note: Set the Stop Station to be less than the Start Station to analyze in the opposite direction. When the Stop Station is less than the Start Station, the offsets are relative to the direction of travel. Therefore, the sign of offsets (negative or positive) do not need to be changed just because the direction of travel changed.
Lock to End
Stop	Specifies the station for the last sight line analysis. Note: Set the Stop Station to be less than the Start Station to analyze in the opposite direction. When the Stop Station is less than the Start Station, the offsets are relative to the direction of travel. Therefore, the sign of offsets (negative or positive) do not need to be changed just because the direction of travel changed.
Settings File Name	Specifies the file to be used that pre-populates the settings on the dialog box. The actual settings on the dialog box are used when the tool is executed. The settings file is only used as a quick way to pre-populate the dialog box.
Visibility Type	Lists all the Speed Tables found in the Settings File. Changing the Visibility Type changes the list of available Speed Table Entries. Also, the Eye Position and Object Position settings for Move Target, Interval, Offset and Height are changed when the Visibility Type are changed.
Speed	Lists all the Speed Table Entries found in the Settings File that correspond to the selected Visibility Type. Changing the speed changes Required Distance and Relaxed Distance based on the Visibility Type and Speed selected.
Required Distance	Specifies the sight distance that must be achieved.

Settings	Description
Relaxed Distance	Specifies a sight distance that is considered a relaxed distance if the achieved sight distance is greater than or equal to the Relaxed Sight Distance and also less than required sight distance.

Settings	Description
Eye Position	The Eye position's xy location is calculated by projecting the station along the Control Reference to the Eye Reference alignment and then applying the offset. The elevation used for the Eye Position is determined by the elevation of the specified design surface at the Eye Position's xy location.
Interval	Specifies the interval along Control Alignment at which sight line calculations are made.
Offset	Specifies an offset from the Eye Reference alignment. A negative offset is to the left of the Eye Reference alignment relative to the direction of travel.
Height	Specifies the value by which the eye position elevation is offset from the highest selected surface.

Settings	Description
Object Position
Move Target to Achieve Visibility	The Object position's XY location is calculated similar to the Eye Position. However, for object position, the location is down range from the Eye Position along the Control Reference alignment a distance equal to the Required Distance. Note: When Move Target is On a sight line for each Object Position Interval is analyzed until the Required distance is either achieved for that Eye Position or an intersection with a design or exiting terrain or mesh is found. In the case where an intersection is found and the Required Sight Distance has not been achieved, the analysis displays the last successful sight line for that eye position.
Interval	Specifies the interval along Control Alignment at which sight line calculations are made. Note: Only used when Move Target is Off.
Offset	Specifies an offset from the Object Reference alignment. A negative offset is to the left of the Object Reference alignment relative to the direction of travel.
Height	Specifies the value by which the object position elevation is offset from the highest selected surface.

Settings	Description
Features
Feature Definition	Choose the feature definition that describes the element being created. Used as a basis for symbology of the created element.
Name	Name of created element, default based on Feature Definition settings. Override this with a new name if needed.

Settings

Description

Features

Feature Definition

Choose the feature definition that describes the element being created.

Used as a basis for symbology of the created element.

Name

Name of created element, default based on Feature Definition settings. Override this with a new name if needed.

Sight Visibility Workflow

Step 1- Select Settings File (*.xml).

Step 2 - Select Method (workflow will change based on the method selected, follow prompts).

Step 3- Enter Speed value.

Step 4- Specify Required Distance.

Step 5 - Specify Relaxed Distance.

Step 6- Locate a corridor or alignment.

Step 7- Locate Eye Control Alignment: Specify centerline or another feature or Reset for Main Alignment.

Step 8- Locate Object Control Alignment: Specify centerline or another feature or Reset for Main Alignment.

Step 9 - Specify Start Station (<Alt> Lock to Start).

Step 10 - Specify End Station (<Alt> Lock to End).

Step 11- Specify the eye position: interval, heigh, offset from centerline.

Step 12 - Specify Object Position: Check on or off "Move target to achieve Visibility", specify Offset and Height.

Step 13- Locate Existing Surface or Reset to Skip.

Step 14 - Sight Visibility Results displays.