Gates Classification

Gates are control points that vehicles pass through. In AITracker they define entry and exit checkpoints within the measurement area.

When to use gates?

Use gates when:

• you want to define entry and exit checkpoints at an intersection,
• you measure traffic in a parking lot or another multi-direction area,
• you prepare the scene for movement creation.

How a gate works

Each gate is defined by:

• ID: Automatically assigned (A, B, C, D, ...)
• Type: Determines the gate role
• Line position: Drawn on the video frame
• Direction vector: Arrow perpendicular to the gate line; only crossings in arrow direction are counted
• Crossing angle: Accepted direction cone around the gate direction vector, default 150°

Gate Types

Type	Color	Symbol	Purpose
Entry	🟢 Green	→	Entry points to the area
Exit	🔴 Red	←	Exit points from the area
Bidirectional	🟡 Yellow	↔	Serves as both entry and exit

Creating gates

Step 1: Create gates

1. Navigate to Design → Gates tab
2. Select gate type (Entry/Exit/Bidirectional)
3. Click "Add Gate" button
4. Draw a line on the video frame at the checkpoint location
5. Repeat for all entry/exit points (minimum 2 gates)

Gate crossing angle

Each gate shows a semi-circle at its center. This marker visualizes the accepted crossing angle:

• The default angle is 75°.
• Drag the handle on the semi-circle to change the angle.
• The current angle is displayed above the semi-circle while you drag the handle and disappears when you release it.
• Smaller values make crossing detection stricter; larger values allow more diagonal crossings.
• Entry and Exit gates show one semi-circle in the gate direction.
• Bidirectional gates show two mirrored semi-circles, one for each accepted direction.