# driving.scenario.targetsToEgo

Convert target poses from scenario to ego coordinates

## Description

targetPosesEgoCoords = driving.scenario.targetsToEgo(targetPosesScenarioCoords,egoPose) converts the poses of target actors from the world coordinates of a driving scenario to the coordinate system relative to the pose of an ego actor. A pose is the position, velocity, and orientation of an actor. For more details on the coordinate systems of actors, see Ego Vehicle and Targets.

example

targetPosesEgoCoords = driving.scenario.targetsToEgo(targetPosesScenarioCoords,egoActor) converts target poses by using the pose of the specified ego actor.

## Examples

collapse all

In a simple driving scenario, obtain the poses of target vehicles in the coordinate system of the ego vehicle. Then convert these poses back to the world coordinates of the driving scenario.

Create a driving scenario.

scenario = drivingScenario;

Create target actors.

actor(scenario,'ClassID',1, ...
'Position',[10 20 30], ...
'Velocity',[12 113 14], ...
'Yaw',54, ...
'Pitch',25, ...
'Roll',22, ...
'AngularVelocity',[24 42 27]);

actor(scenario,'ClassID',1, ...
'Position',[17 22 12], ...
'Velocity',[19 13 15], ...
'Yaw',45, ...
'Pitch',52, ...
'Roll',2, ...
'AngularVelocity',[42 24 29]);

egoActor = actor(scenario,'ClassID',1, ...
'Position',[1 2 3], ...
'Velocity',[1.2 1.3 1.4], ...
'Yaw',4, ...
'Pitch',5, ...
'Roll',2, ...
'AngularVelocity',[4 2 7]);

Use the actorPoses function to return the poses of all actors in the scenario. Pose properties (position, velocity, and orientation) are in the world coordinates of the driving scenario. Save the target actors to a separate variable and inspect the pose of the first target actor.

allPoses = actorPoses(scenario);
targetPosesScenarioCoords = allPoses(1:2);
targetPosesScenarioCoords(1)
ans = struct with fields:
ActorID: 1
Position: [10 20 30]
Velocity: [12 113 14]
Roll: 22
Pitch: 25
Yaw: 54
AngularVelocity: [24 42 27]

Use the driving.scenario.targetsToEgo function to convert the target poses to the ego-centric coordinates of the ego actor. Inspect the pose of the first actor.

targetPosesEgoCoords = driving.scenario.targetsToEgo(targetPosesScenarioCoords,egoActor);
targetPosesEgoCoords(1)
ans = struct with fields:
ActorID: 1
Position: [7.8415 18.2876 27.1675]
Velocity: [18.6826 112.0403 9.2960]
Roll: 16.4327
Pitch: 23.2186
Yaw: 47.8114
AngularVelocity: [-3.3744 47.3021 18.2569]

Alternatively, use the targetPoses function to obtain all target actor poses in ego vehicle coordinates. Display the first target pose, which matches the previously calculated pose.

targetPosesEgoCoords = targetPoses(egoActor);
targetPosesEgoCoords(1)
ans = struct with fields:
ActorID: 1
ClassID: 1
Position: [7.8415 18.2876 27.1675]
Velocity: [18.6826 112.0403 9.2960]
Roll: 16.4327
Pitch: 23.2186
Yaw: 47.8114
AngularVelocity: [-3.3744 47.3021 18.2569]

Use the driving.scenario.targetsToScenario to convert the target poses back to the world coordinates of the scenario. Display the first target pose, which matches the original target pose.

targetPosesScenarioCoords = driving.scenario.targetsToScenario(targetPosesEgoCoords,egoActor);
targetPosesScenarioCoords(1)
ans = struct with fields:
ActorID: 1
ClassID: 1
Position: [10.0000 20.0000 30.0000]
Velocity: [12.0000 113.0000 14.0000]
Roll: 22
Pitch: 25.0000
Yaw: 54
AngularVelocity: [24.0000 42.0000 27.0000]

## Input Arguments

collapse all

Target poses in the world coordinates of a driving scenario, specified as a structure or an array of structures.

Each target pose structure must contain at least these fields.

FieldDescription
ActorID

Scenario-defined actor identifier, specified as a positive integer.

Position

Position of actor, specified as a real-valued vector of the form [x y z]. Units are in meters.

Velocity

Velocity (v) of actor in the x- y-, and z-directions, specified as a real-valued vector of the form [vx vy vz]. Units are in meters per second.

Roll

Roll angle of actor, specified as a real-valued scalar. Units are in degrees.

Pitch

Pitch angle of actor, specified as a real-valued scalar. Units are in degrees.

Yaw

Yaw angle of actor, specified as a real-valued scalar. Units are in degrees.

AngularVelocity

Angular velocity (ω) of actor in the x-, y-, and z-directions, specified as a real-valued vector of the form [ωx ωy ωz]. Units are in degrees per second.

For full definitions of these structure fields, see the actor and vehicle functions.

Ego actor pose in the world coordinates of a driving scenario, specified as a structure.

The ego actor pose structure must contain at least these fields.

FieldDescription
ActorID

Scenario-defined actor identifier, specified as a positive integer.

Position

Position of actor, specified as a real-valued vector of the form [x y z]. Units are in meters.

Velocity

Velocity (v) of actor in the x- y-, and z-directions, specified as a real-valued vector of the form [vx vy vz]. Units are in meters per second.

Roll

Roll angle of actor, specified as a real-valued scalar. Units are in degrees.

Pitch

Pitch angle of actor, specified as a real-valued scalar. Units are in degrees.

Yaw

Yaw angle of actor, specified as a real-valued scalar. Units are in degrees.

AngularVelocity

Angular velocity (ω) of actor in the x-, y-, and z-directions, specified as a real-valued vector of the form [ωx ωy ωz]. Units are in degrees per second.

For full definitions of these structure fields, see the actor and vehicle functions.

Ego actor in the world coordinates of a driving scenario, specified as an Actor or Vehicle object. The function converts the coordinates of target actors relative to the pose of egoActor. The pose information is stored in the Position, Velocity, Roll, Pitch, Yaw, and AngularVelocity properties of the ego actor.

For the full definitions of pose properties, see the actor and vehicle functions.

## Output Arguments

collapse all

Target poses in ego vehicle coordinates, returned as a structure or an array of structures.

At a minimum, each returned target pose structure has these fields.

FieldDescription
ActorID

Scenario-defined actor identifier, specified as a positive integer.

Position

Position of actor, specified as a real-valued vector of the form [x y z]. Units are in meters.

Velocity

Velocity (v) of actor in the x- y-, and z-directions, specified as a real-valued vector of the form [vx vy vz]. Units are in meters per second.

Roll

Roll angle of actor, specified as a real-valued scalar. Units are in degrees.

Pitch

Pitch angle of actor, specified as a real-valued scalar. Units are in degrees.

Yaw

Yaw angle of actor, specified as a real-valued scalar. Units are in degrees.

AngularVelocity

Angular velocity (ω) of actor in the x-, y-, and z-directions, specified as a real-valued vector of the form [ωx ωy ωz]. Units are in degrees per second.

The returned targetPosesEgoCoords structures include the same fields as those in the input targetPosesScenarioCoords structures. For example, if the input structures include a ClassID field, then the returned structures also include ClassID.

For full definitions of these structure fields, see the actor and vehicle functions.

collapse all

### Ego Vehicle and Targets

In a driving scenario, you can specify one actor as the observer of all other actors, similar to how the driver of a car observes all other cars. The observer actor is called the ego actor or, more specifically, the ego vehicle. From the perspective of the ego vehicle, all other actors (such as vehicles and pedestrians) are the observed actors, called targets. Ego vehicle coordinates are centered and oriented with reference to the ego vehicle. The coordinates of the driving scenario are world coordinates.

## Version History

Introduced in R2017a