Triggers reference — all 19 scenario conditions

A TRIGGER decides when an event’s actions start. drawtonomy offers 19 conditions in the trigger dropdown, plus a handful more behind Advanced….

Eight conditions sit under COMMON. The remaining eleven are behind a collapsed More conditions… row — click it to expand.

New events start with Simulation time at 0.00 s.

COMMON

UI label	OpenSCENARIO	Fires when
Immediately (no condition)	(no condition)	Straight away. Only offered as the first condition of a trigger, and never on END CONDITIONS.
Simulation time	SimulationTimeCondition	The run reaches a given number of seconds.
Time gap to actor	TimeHeadwayCondition	The headway to another actor crosses a threshold, in seconds.
Time to collision	TimeToCollisionCondition	The projected time to collision with another actor crosses a threshold.
Distance to actor	RelativeDistanceCondition	The distance to another actor crosses a threshold, in metres.
Traveled distance	TraveledDistanceCondition	The actor has driven a given distance since the run started.
Phase / event state	StoryboardElementStateCondition	A named phase or event starts, is running, ends, or is complete.
Distance to point	DistanceCondition	The distance from the actor to a fixed point crosses a threshold. Monitors distance continuously.

More conditions…

UI label	OpenSCENARIO	Fires when
Reach position	ReachPositionCondition	The actor comes within a tolerance radius of a point. An arrival test rather than a distance monitor.
End of road	EndOfRoadCondition	The actor has been at the end of the road for a given duration.
Actor speed	SpeedCondition	The actor’s own speed crosses a threshold.
Relative speed	RelativeSpeedCondition	The actor’s speed relative to another actor crosses a threshold.
Stand still	StandStillCondition	The actor has been stationary for a given duration.
Actor acceleration	AccelerationCondition	The actor’s acceleration crosses a threshold.
Collision	CollisionCondition	The actor collides with another entity.
Off-road	OffroadCondition	The actor has been off the drivable surface for a given duration.
Scenario parameter	ParameterCondition	A declared parameter compares to a value.
Scenario variable	VariableCondition	A declared variable compares to a value.
Traffic signal	TrafficSignalCondition	A named signal reaches a given state.

Tip

Distance to point and Reach position are easy to confuse. Distance to point watches the distance and fires when it crosses your threshold — so it can fire on the way in or on the way out, depending on the rule. Reach position fires once the actor is inside the tolerance radius. Use Reach position for “when it gets there”, and Distance to point for “while it is closer than / further than”.

Advanced conditions

Some conditions do not appear in the dropdown at all. Click the small Advanced… link under a condition row to reach them:

UI label	OpenSCENARIO
Relative clearance	RelativeClearanceCondition
Angle	AngleCondition
Relative angle	RelativeAngleCondition
Traffic signal controller	TrafficSignalControllerCondition
Time of day	TimeOfDayCondition
User-defined value	UserDefinedValueCondition

Combining conditions

A trigger is a set of groups. The editor shows the first group under the heading ALL OF (AND).

• + and adds a condition to the current group. Every condition in a group must hold at once — the group maps to one OpenSCENARIO ConditionGroup.
• or… starts a new group, shown as Any of (OR). Any single group being satisfied satisfies the trigger — multiple ConditionGroup elements are OR-ed by the standard.

So (A and B) or C is two groups: one holding A and B, one holding C.

Common fields

The fields shown depend on the condition, but these recur:

Field	Meaning
ACTOR	The actor whose state is measured — the triggering entity.
REFERENCE ACTOR	The other actor, for conditions that compare two of them.
SECONDS	The threshold, for time-based conditions.
exceeds / falls below	The comparison rule. Which is the default depends on the condition.
DELAY AFTER MET	In the event’s ADVANCED section: hold the event back this many seconds after the condition is satisfied. Maps to Condition@delay.

See also

• Actions reference — what happens once a trigger fires.
• Phases and events — phase Start conditions use the same catalogue.
• End and fail conditions — the same conditions, used to stop a run or fail it.