Knowledge Base

Define an Entry Zone

Aim

To define a region of the arena where the subject must be immediately before moving into the hidden zone and disappearing from view.

It is important that at least one sampled location of the subject's body point is found in the entry zone for the subject to be considered in the hidden zone. Otherwise, the subject is considered missing. Make the entry zone large enough.

Prerequisites

You have defined a Hidden zone. See Shelters and Other Hidden Zones.

To Define an Entry Zone

1. In the Arenas and Zones section, select the Entry Zone Group row.
2. Draw a zone that covers the area, overlapping the hidden zone, to define as an entry zone. The size of the entry zone is critical; it must be wide enough, but not too wide, so that:
   • When entering: the subject never goes straight away from the area outside the entry zone to the hidden zone. There should be at least one instance of the subject's body point within the entry zone before disappearing from view. If necessary, increase your sample rate to make sure that this happens.
   • When exiting: the subject's body point is far, but not too far from the hidden zone when it crosses the entry zone border to the rest of the arena, just enough for it to be considered as having left the hidden zone. This only applies if you select Use This Entry Zone Also as Leaving Zone.
   You can use the Integrated Visualization to help you set the right size.
3. If the Auto-label zone option is activated, the Add Entry Zone window opens. If the auto-label option is switched off, click the Add Zone Label button on the toolbar and click the zone to open the Add Entry Zone window.
4. In the Add Entry Zone window, link this entry zone to the appropriate hidden zone by selecting the Link box under Linked Hidden Zone. You can link more than one entry zone to a hidden zone, but you cannot link more than one hidden zone to an entry zone.
5. If you want to define the entry zone also as a leaving zone, select the check box for Use This Entry Zone Also as Leaving Zone. This will be applied to all hidden zones in your Arena Settings. Each entry zone will also be used as a leaving zone for the hidden zone associated with it.
6. Click OK to assign the label to the entry zone.

Notes:

• To display the hidden zone while drawing the entry zone, in the Arenas and Zones section, select the check box in the View column of the Hidden Zone Group row, next to the Color column.
• If you have multiple arenas, create hidden zones and entry zones in the first arena first, then duplicate that arena and its contents. See Duplicate an Arena.

To Link a Hidden Zone to an Entry Zone

If you did not link an entry zone to its hidden zone when you defined the hidden zone, you can do one of the following:

• In the video image, right-click the hidden zone label or right-click the hidden zone row in the Arena Settings window. Select Link Entry Zones and select the Link check box of the appropriate entry zone in the Links to Entry Zones window.
• In the video image, right-click the entry zone label, or right-click the entry zone row in the Arena Settings window. Select Link Hidden Zones and select the Link check box of the appropriate hidden zone in the Link to Hidden Zone window.

Change the Hidden Zone Subject Coordinates

Aim

To specify the coordinates of the subject when it is in the hidden zone.

When a subject enters a hidden zone, its body points are assumed to be in the center of the hidden zone. However, if you have a very large hidden zone, the distance the subject moves from the entry zone to the center of the hidden zone every time it enters the hidden zone contributes rather significantly to Distance Moved. In these cases, you can move the coordinates of the subject near the entry zone.

Prerequisites

You have defined a hidden zone. See Shelters and Other Hidden Zones.

To Set the Hidden Zone Subject Coordinates

1. Right-click the hidden zone label and select Hidden Subject Coordinates.
2. Select one of two options to set the hidden subject coordinates:
   • Center of the Zone, unless the center is outside the zone, in which case it is the arrow tip location. Select this option when you have a small hidden zone.
   • Arrow Tip Location. Select this option when you have a large hidden zone, to minimize the contribution to Distance Moved.