QCar

Description

QCars are considered “actors” in Quanser Interactive Labs. The QCar library can be used to acquire sensor data from the virtual environment and controls the motion of the vehicles.

See the QCar Tutorial to get a better understanding of using QCars in Quanser Interactive Labs.

Library

class qvl.qcar.QLabsQCar(qlabs, verbose=False)[source]: This class is for spawning QCars.

Constants

QLabsQCar.ID_QCAR = 160: Class ID

Note

CSI camera resolution is 820x410.

QLabsQCar.CAMERA_CSI_RIGHT = 0

QLabsQCar.CAMERA_CSI_BACK = 1

QLabsQCar.CAMERA_CSI_LEFT = 2

QLabsQCar.CAMERA_CSI_FRONT = 3

Note

RGB and depth resolution is 640x480.

QLabsQCar.CAMERA_RGB = 4

QLabsQCar.CAMERA_DEPTH = 5

Note

Overhead and trailing cameras support user zoom using the mouse wheel.

QLabsQCar.CAMERA_OVERHEAD = 6

QLabsQCar.CAMERA_TRAILING = 7

Member Variables

QLabsQCar.actorNumber = None: The current actor number of this class to be addressed. This will be set by spawn methods and cleared by destroy methods. It will not be modified by the destroy all actors. This can be manually altered at any time to use one object to address multiple actors.

Methods

QLabsQCar.set_transform_and_request_state(location, rotation, enableDynamics, headlights, leftTurnSignal, rightTurnSignal, brakeSignal, reverseSignal, waitForConfirmation=True)[source]

Sets the location, rotation, and other car properties. Note that setting the location ignores collisions so ensure that the location is free of obstacles that may trap the actor if it is subsequently used in a dynamic mode. This transform can also be used to “playback” previously recorded position data without the need for a full dynamic model.

Parameters

location (float array[3]) – An array of floats for x, y and z coordinates in full-scale units. Multiply physical QCar locations by 10 to get full scale locations.
rotation (float array[3]) – An array of floats for the roll, pitch, and yaw in radians
enableDynamics (boolean) – (default True) Enables or disables gravity for set transform requests.
headlights (boolean) – Enable the headlights
leftTurnSignal (boolean) – Enable the left turn signal
rightTurnSignal (boolean) – Enable the right turn signal
brakeSignal (boolean) – Enable the brake lights (does not affect the motion of the vehicle)
reverseSignal (boolean) – Play a honking sound
waitForConfirmation (boolean) – (Optional) Wait for confirmation before proceeding. This makes the method a blocking operation. NOTE: Return data will only be valid if waitForConfirmation is True.

Returns

status - True if successful or False otherwise
location - in full scale
rotation - in radians
forward vector - unit scale vector
up vector - unit scale vector
front bumper hit - True if in contact with a collision object, False otherwise
rear bumper hit - True if in contact with a collision object, False otherwise

Return type

boolean, float array[3], float array[3], float array[3], float array[3], boolean, boolean

QLabsQCar.set_transform_and_request_state_degrees(location, rotation, enableDynamics, headlights, leftTurnSignal, rightTurnSignal, brakeSignal, reverseSignal, waitForConfirmation=True)[source]

Sets the location, rotation, and other car properties. Note that setting the location ignores collisions so ensure that the location is free of obstacles that may trap the actor if it is subsequently used in a dynamic mode. This transform can also be used to “playback” previously recorded position data without the need for a full dynamic model.

Parameters

location (float array[3]) – An array of floats for x, y and z coordinates in full-scale units. Multiply physical QCar locations by 10 to get full scale locations.
rotation (float array[3]) – An array of floats for the roll, pitch, and yaw in degrees.
enableDynamics (boolean) – (default True) Enables or disables gravity for set transform requests.
headlights (boolean) – Enable the headlights.
leftTurnSignal (boolean) – Enable the left turn signal.
rightTurnSignal (boolean) – Enable the right turn signal.
brakeSignal (boolean) – Enable the brake lights (does not affect the motion of the vehicle).
reverseSignal (boolean) – Enable the reverse lights.
waitForConfirmation (boolean) – (Optional) Wait for confirmation before proceeding. This makes the method a blocking operation. NOTE: Return data will only be valid if waitForConfirmation is True.

Returns

status - True if successful or False otherwise
location - in full scale
rotation - in radians
forward vector - unit scale vector
up vector - unit scale vector
front bumper hit - True if in contact with a collision object, False otherwise
rear bumper hit - True if in contact with a collision object, False otherwise

Return type

boolean, float array[3], float array[3], float array[3], float array[3], boolean, boolean

QLabsQCar.set_velocity_and_request_state(forward, turn, headlights, leftTurnSignal, rightTurnSignal, brakeSignal, reverseSignal)[source]

Sets the velocity, turn angle in radians, and other car properties.

Parameters

forward (float) – Speed in m/s of a full-scale car. Multiply physical QCar speeds by 10 to get full scale speeds.
turn (float) – Turn angle in radians. Positive values turn right.
headlights (boolean) – Enable the headlights.
leftTurnSignal (boolean) – Enable the left turn signal.
rightTurnSignal (boolean) – Enable the right turn signal.
brakeSignal (boolean) – Enable the brake lights (does not affect the motion of the vehicle).
reverseSignal (boolean) – Enable the reverse lights.

Returns

status - True if successful, False otherwise
location
rotation - in radians
front bumper hit - True if in contact with a collision object, False otherwise
rear bumper hit - True if in contact with a collision object, False otherwise

Return type

boolean, float array[3], float array[3], boolean, boolean

QLabsQCar.set_velocity_and_request_state_degrees(forward, turn, headlights, leftTurnSignal, rightTurnSignal, brakeSignal, reverseSignal)[source]

Sets the velocity, turn angle in degrees, and other car properties.

Parameters

forward (float) – Speed in m/s of a full-scale car. Multiply physical QCar speeds by 10 to get full scale speeds.
turn (float) – Turn angle in degrees. Positive values turn right.
headlights (boolean) – Enable the headlights.
leftTurnSignal (boolean) – Enable the left turn signal.
rightTurnSignal (boolean) – Enable the right turn signal.
brakeSignal (boolean) – Enable the brake lights (does not affect the motion of the vehicle).
reverseSignal (boolean) – Enable the reverse lights.

Returns

status - True if successful, False otherwise
location
rotation - in radians
front bumper hit - True if in contact with a collision object, False otherwise
rear bumper hit - True if in contact with a collision object, False otherwise

Return type

boolean, float array[3], float array[3], boolean, boolean

QLabsQCar.possess(camera=CAMERA_TRAILING)[source]

Possess (take control of) a QCar in QLabs with the selected camera.

Parameters

camera (uint32) – Pre-defined camera constant. See CAMERA constants for available options. Default is the trailing camera.

Returns

status - True if possessing the camera was successful, False otherwise

Return type

boolean

QLabsQCar.ghost_mode(enable=True, color=[0, 1, 0])[source]

Ghost mode changes the selected QCar actor into a transparent colored version. This can be useful as a reference actor or indicating a change in state.

Parameters

enable (boolean) – Set the QCar to the defined transparent color, otherwise revert to the solid color scheme.
color (float array[3]) – Red, Green, Blue components of the RGB color on a 0.0 to 1.0 scale.

Returns

status - True if successful, False otherwise

Return type

boolean

QLabsQCar.get_image(camera)[source]

Request a JPG image from one of the QCar cameras.

Parameters

camera (uint32) – Pre-defined camera constant. See CAMERA constants for available options. Trailing and Overhead cameras cannot be selected.

Returns

status - True and image data if successful, False and empty otherwise
imageData - Image in a JPG format

Return type

boolean, byte array with jpg data

QLabsQCar.get_lidar(samplePoints=400)[source]

Request LIDAR data from a QCar.

Parameters: samplePoints (uint32) – (Optional) Change the number of points per revolution of the LIDAR.
Returns: True, angles in radians, and distances in m if successful, False, none, and none otherwise
Return type: boolean, float array, float array

Parent Class (actor.py) Methods

QLabsQCar.__init__(qlabs, verbose=False)[source]

Constructor Method

Parameters

qlabs (object) – A QuanserInteractiveLabs object
verbose (boolean) – (Optional) Print error information to the console.

QLabsQCar.spawn(location=[0, 0, 0], rotation=[0, 0, 0], scale=[1, 1, 1], configuration=0, waitForConfirmation=True)[source]

Spawns a new QCar actor with the next available actor number within this class.

Parameters

location (float array[3]) – (Optional) An array of floats for x, y and z coordinates
rotation (float array[3]) – (Optional) An array of floats for the roll, pitch, and yaw in radians
scale (float array[3]) – (Optional) An array of floats for the scale in the x, y, and z directions. Scale values of 0.0 should not be used and only uniform scaling is recommended. Sensor scaling will be based on scale[0].
configuration (uint32) – (Optional) Spawn configuration. See class library for configuration options.
waitForConfirmation (boolean) – (Optional) Make this operation blocking until confirmation of the spawn has occurred. Note that if this is False, the returned actor number will be invalid.

Returns

status - 0 if successful, 1 class not available, 3 unknown error, -1 communications error.
actorNumber - An actor number to use for future references.

Return type

int32, int32

QLabsQCar.spawn_degrees(location=[0, 0, 0], rotation=[0, 0, 0], scale=[1, 1, 1], configuration=0, waitForConfirmation=True)[source]

Spawns a new QCar actor with the next available actor number within this class.

Parameters

location (float array[3]) – (Optional) An array of floats for x, y and z coordinates
rotation (float array[3]) – (Optional) An array of floats for the roll, pitch, and yaw in degrees
scale (float array[3]) – (Optional) An array of floats for the scale in the x, y, and z directions. Scale values of 0.0 should not be used and only uniform scaling is recommended. Sensor scaling will be based on scale[0].
configuration (uint32) – (Optional) Spawn configuration. See class library for configuration options.
waitForConfirmation (boolean) – (Optional) Make this operation blocking until confirmation of the spawn has occurred. Note that if this is False, the returned actor number will be invalid.

Returns

status - 0 if successful, 1 class not available, 3 unknown error, -1 communications error.
actorNumber - An actor number to use for future references.

Return type

int32, int32

QLabsQCar.spawn_id(actorNumber, location=[0, 0, 0], rotation=[0, 0, 0], scale=[1, 1, 1], configuration=0, waitForConfirmation=True)[source]

Spawns a new QCar actor.

Parameters

actorNumber (uint32) – User defined unique identifier for the class actor in QLabs
location (float array[3]) – (Optional) An array of floats for x, y and z coordinates
rotation (float array[3]) – (Optional) An array of floats for the roll, pitch, and yaw in radians
scale (float array[3]) – (Optional) An array of floats for the scale in the x, y, and z directions. Scale values of 0.0 should not be used and only uniform scaling is recommended. Sensor scaling will be based on scale[0].
configuration (uint32) – (Optional) Spawn configuration. See class library for configuration options.
waitForConfirmation (boolean) – (Optional) Make this operation blocking until confirmation of the spawn has occurred.

Returns

status - 0 if successful, 1 class not available, 2 actor number not available or already in use, 3 unknown error, -1 communications error

Return type

int32

QLabsQCar.spawn_id_degrees(actorNumber, location=[0, 0, 0], rotation=[0, 0, 0], scale=[1, 1, 1], configuration=0, waitForConfirmation=True)[source]

Spawns a new QCar actor.

Parameters

actorNumber (uint32) – User defined unique identifier for the class actor in QLabs
location (float array[3]) – (Optional) An array of floats for x, y and z coordinates
rotation (float array[3]) – (Optional) An array of floats for the roll, pitch, and yaw in radians
scale (float array[3]) – (Optional) An array of floats for the scale in the x, y, and z directions. Scale values of 0.0 should not be used and only uniform scaling is recommended. Sensor scaling will be based on scale[0].
configuration (uint32) – (Optional) Spawn configuration. See class library for configuration options.
waitForConfirmation (boolean) – (Optional) Make this operation blocking until confirmation of the spawn has occurred.

Returns

status - 0 if successful, 1 class not available, 2 actor number not available or already in use, 3 unknown error, -1 communications error

Return type

int32

QLabsQCar.destroy()

Find and destroy a specific actor. This is a blocking operation.

Returns

numActorsDestroyed - The number of actors destroyed. -1 if failed.

Return type

int32

QLabsQCar.destroy_all_actors_of_class()

Find and destroy all actors of this class. This is a blocking operation.

Returns

numActorsDestroyed - The number of actors destroyed. -1 if failed.

Return type

int32

QLabsQCar.ping()

Checks if the actor is still present in the environment. Note that if you did not spawn the actor with one of the spawn functions, you may need to manually set the actorNumber member variable.

Returns

status - True if successful, False otherwise

Return type

boolean

QLabsQCar.get_world_transform()

Get the location, rotation, and scale in world coordinates of the actor.

Returns

status - True if successful, False otherwise
location
rotation
scale

Return type

boolean, float array[3], float array[3], float array[3]

QLabsQCar.get_world_transform_degrees()

Get the location, rotation, and scale in world coordinates of the actor.

Returns

status - True if successful, False otherwise
location
rotation
scale

Return type

boolean, float array[3], float array[3], float array[3]

Configurations

There is only one configuration of the QCar actor.

Connection Points

Reference Frame Number	Parent Frame	Relative Transform to Parent (Location, Rotation)	Description
0			The base frame is located at ground level, centered between the two rear wheels. This represents the location of the car with no filtering, suspension, or dynamics. Collision detection is connected to this reference frame.
1	0	[0,0,0] [0,0,0]	The filtered frame is co-located with connection point 0, but it is a filtered position to simulated the suspension and dynamic effects. All the visual elements and sensors of the QCar are connected to this frame.

Component Extrinsics

“Extrinsics” refer to the external relationship of an object with respect to a specific frame of reference (in this case the body center of the QCar). Sometimes it’s important to know specific distances and orientation of extrinsic components, for instance, this can be use for obstacle detection and camera calibration. You will find a list of the important extrinsics below.

Distances From Body Center

The body frame is located between the front and rear axles on the ground plane. Distances of the QCar in its virtual environment are 10 times larger than on the physical system so a QCar spawned at a scale of 1 is equivalent size to a full-scale automobile. A QCar spawned at a scale of 0.1 will be equivalent to the size of a physical QCar.

Component	x (m)	y (m)	z (m)
CG	0.248	-0.074	0.709
Front axle	1.300	0	0.310
Rear axle	-1.300	0	0.310
CSI front	1.930	0	0.953
CSI left	0.140	0.438	0.953
CSI rear	-1.650	0	0.953
CSI right	0.140	-0.674	0.953
IMU	1.278	0.223	0.895
RealSense	0.822	0.003	1.582
RPLIDAR	-0.108	-0.001	1.799

Transformation Matrices

All transformation matrices are built off of the body frame and camera frames for the QCar. To read more about this check out our documentation here by clicking on Research Resources link and looking inside the zip folder for src/user_manuals/qcar/user_manual_system_hardware.pdf

QCar Tutorial

Python Tutorial

Raw to download this tutorial: QCar Tutorial (.py).

"""
QCar Library Example
----------------------
This example will show you how to spawn cars, and use the qvl library commands
to control the car and its related functions.

.. note::

    Make sure you have Quanser Interactive Labs open before running this
    example.  This example is designed to best be run in QCar Cityscape.

"""

from qvl.qlabs import QuanserInteractiveLabs
from qvl.free_camera import QLabsFreeCamera
from qvl.basic_shape import QLabsBasicShape
from qvl.qcar import QLabsQCar
from qvl.environment_outdoors import QLabsEnvironmentOutdoors

import time
import math
import numpy as np
import cv2
import os

import pyqtgraph as pg
from pyqtgraph.Qt import QtWidgets

from qvl.system import QLabsSystem



def main():
    os.system('cls')

    #Communications with qlabs

    qlabs = QuanserInteractiveLabs()
    cv2.startWindowThread()

    print("Connecting to QLabs...")
    if (not qlabs.open("localhost")):
        print("Unable to connect to QLabs")
        return    

    print("Connected")

    qlabs.destroy_all_spawned_actors()

    # Use hSystem to set the tutorial title in the upper left of the qlabs window 
    hSystem = QLabsSystem(qlabs)
    hSystem.set_title_string('QCar Tutorial')

    ### QCar

    hCameraQCars = QLabsFreeCamera(qlabs)
    hCameraQCars.spawn_id(actorNumber=1, location=[-15.075, 26.703, 6.074], rotation=[0, 0.564, -1.586])
    hCameraQCars.possess()

    print("\n\n---QCar---")

    #spawning the QCar with radians
    hQCar0 = QLabsQCar(qlabs)
    hQCar0.spawn_id(actorNumber=0, location=[-8.700, 14.643, 0.005], rotation=[0,0,math.pi/2], waitForConfirmation=True)

    #Spawn and destroy the existing QCar
    hQCar1 = QLabsQCar(qlabs)
    hQCar1.spawn_id(actorNumber=1, location=[-15.075, 26.703, 6.074], rotation=[0,0,math.pi/2], waitForConfirmation=True)
    hQCar1.destroy()

    #spawn a QCar with degrees
    hQCar2 = QLabsQCar(qlabs)
    x = hQCar2.spawn_id_degrees(actorNumber=2, location=[-11.048, 14.643, 0.005], rotation=[0,0,90], waitForConfirmation=True)

    #pinging the QCar
    hQCar2.ping()

    time.sleep(0.5)

    # Set the velocity and direction of the QCar in radians while also turning on the headlights and right turn signal
    hQCar2.set_velocity_and_request_state(forward=1, turn = -math.pi/6, headlights=True, leftTurnSignal=False, rightTurnSignal=True, brakeSignal=False, reverseSignal=False)
    time.sleep(1)
    # Set the velocity to 0 and direction of the QCar in radians while keeping the headlights on and right turn signal on
    hQCar2.set_velocity_and_request_state(forward=0.0, turn = -math.pi/6, headlights=True, leftTurnSignal=False, rightTurnSignal=True, brakeSignal=False, reverseSignal=False)
    # Set the velocity to 1 and direction of the QCar in degrees while keeping the headlights on and turning on the left turn signal
    hQCar2.set_velocity_and_request_state_degrees(forward=1, turn = 30, headlights=True, leftTurnSignal=True, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)
    time.sleep(1)
    # Set the velocity to 0 and direction of the QCar in degrees while keeping the headlights on and left turn signal on
    success, location, rotation, frontHit, rearHit = hQCar2.set_velocity_and_request_state_degrees(forward=0.0, turn = 30, headlights=True, leftTurnSignal=True, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)

    # Possess another QCar
    x = hQCar2.possess()

    time.sleep(0.1)
    # Set the velocity to 1 of the QCar in radians while keeping the headlights, brakeSignal and reverseSignal on
    hQCar2.set_velocity_and_request_state(forward=1, turn = 0, headlights=True, leftTurnSignal=True, rightTurnSignal=True, brakeSignal=True, reverseSignal=True)
    time.sleep(1)
    # Set the velocity to 0 while keeping the headlights, brakeSignal and reverseSignal on and turning on the left turn signal and right turn signal
    hQCar2.set_velocity_and_request_state(forward=0.0, turn = 0, headlights=True, leftTurnSignal=True, rightTurnSignal=True, brakeSignal=True, reverseSignal=True)

    # Turn all the lights off
    hQCar2.set_velocity_and_request_state(forward=0, turn = 0, headlights=False, leftTurnSignal=False, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)

    # Car bumper test
    hCameraQCars.possess()
    # Change the camera view to see the bumper test
    hCameraQCars.set_transform(location=[-17.045, 32.589, 6.042], rotation=[0, 0.594, -1.568])

    # Spawn some shapes for our bumper test
    hCubeQCarBlocks = QLabsBasicShape(qlabs)
    hCubeQCarBlocks .spawn_id(100, [-11.919, 26.289, 0.5], [0,0,0], [1,1,1], configuration=hCubeQCarBlocks.SHAPE_CUBE, waitForConfirmation=True)
    hCubeQCarBlocks .spawn_id(101, [-19.919, 26.289, 0.5], [0,0,0], [1,1,1], configuration=hCubeQCarBlocks.SHAPE_CUBE, waitForConfirmation=True)

    # Create another QCar
    hQCar3 = QLabsQCar(qlabs)
    hQCar3.spawn_id(actorNumber=3, location=[-13.424, 26.299, 0.005], rotation=[0,0,math.pi])

    # Have the QCar drive forward to hit the front block
    for count in range(10):
        x, location, rotation, frontHit, rearHit  = hQCar3.set_velocity_and_request_state(forward=2, turn = 0, headlights=False, leftTurnSignal=False, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)
        time.sleep(0.25)

    # Put the QCar in ghost mode
    hQCar3.ghost_mode()

    # Have the QCar drive backwards to hit the back bumper
    for count in range(10):
        x, location, rotation, frontHit, rearHit  = hQCar3.set_velocity_and_request_state(forward=-2, turn = 0, headlights=False, leftTurnSignal=False, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)
        time.sleep(0.25)

    # Change the color of ghost mode to red
    hQCar3.ghost_mode(enable=True, color=[1,0,0])
    time.sleep(0.50)

    # Set the velocity to 0 and turn all lights off
    hQCar3.set_velocity_and_request_state(forward=0, turn = 0, headlights=False, leftTurnSignal=False, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)

    # Set the location of the QCar and request the state of the car.  If x== True and frontHit==True then the front bumper hit the block correctly.
    x, location, rotation, forward_vector, up_vector, frontHit, rearHit = hQCar3.set_transform_and_request_state(location=[-16.1, 26.299, 0.005], rotation=[0,0,math.pi-0.01], enableDynamics=True, headlights=False, leftTurnSignal=False, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)
    time.sleep(0.50)

    # Getting and saving the world transform of the QCar in Quanser Interactive Labs
    x, loc, rot, scale = hQCar3.get_world_transform()

    # Set the location of the QCar and request the state of the car.  If x== True and rearHit==True then the back bumper hit the block correctly.
    x, location, rotation, forward_vector, up_vector, frontHit, rearHit = hQCar3.set_transform_and_request_state_degrees(location=[-13.1, 26.299, 0.005], rotation=[0,0,179], enableDynamics=True, headlights=False, leftTurnSignal=False, rightTurnSignal=False, brakeSignal=False, reverseSignal=False)
    time.sleep(0.50)

    #Turning off ghost mode for the QCar
    hQCar3.ghost_mode(enable=False, color=[1,0,0])

    # Possessing the overhead camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_OVERHEAD)
    time.sleep(0.5)
    
    # Possessing the trailing camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_TRAILING)
    time.sleep(0.5)
    
    #Possessing the front CSI camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_CSI_FRONT)
    time.sleep(0.5)

    # Possessing the right CSI camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_CSI_RIGHT)
    time.sleep(0.5)

    # Possessing the back CSI camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_CSI_BACK)
    time.sleep(0.5)

    # Possessing the left CSI camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_CSI_LEFT)
    time.sleep(0.5)

    # Possessing the front RealSense RGB camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_RGB)
    time.sleep(0.5)

    # Possessing the RealSense depth camera on the QCar
    hQCar2.possess(hQCar2.CAMERA_DEPTH)
    time.sleep(0.5)

    # Getting images from the different cameras 
    x, camera_image = hQCar2.get_image(camera=hQCar2.CAMERA_CSI_FRONT)
    x, camera_image = hQCar2.get_image(camera=hQCar2.CAMERA_CSI_RIGHT)
    x, camera_image = hQCar2.get_image(camera=hQCar2.CAMERA_CSI_BACK)
    x, camera_image = hQCar2.get_image(camera=hQCar2.CAMERA_CSI_LEFT)
    x, camera_image = hQCar2.get_image(camera=hQCar2.CAMERA_RGB)
    x, camera_image = hQCar2.get_image(camera=hQCar2.CAMERA_DEPTH)


    #LIDAR

    hQCar3.possess(hQCar3.CAMERA_OVERHEAD)

    # Creating a plot to plot the LIDAR data 
    lidarPlot = pg.plot(title="LIDAR")
    squareSize = 100
    lidarPlot.setXRange(-squareSize, squareSize)
    lidarPlot.setYRange(-squareSize, squareSize)
    lidarData = lidarPlot.plot([], [], pen=None, symbol='o', symbolBrush='r', symbolPen=None, symbolSize=2)

    time.sleep(1)

    print("Reading from LIDAR... if QLabs crashes or output isn't great, make sure FPS > 100")
    
    # Have the QCar drive forward to hit the front block to show the live lidar.
    # Speed can be changed by increasing or decreasing the value in the first
    # parameter "forward"
    hQCar3.set_velocity_and_request_state(1, 0, False, False, False, False, False)
    lidar_rate = 0.05

    # Obtaining and plotting lidar data for 0.2s
    for count in range(25): 
        
        success, angle, distance = hQCar3.get_lidar(samplePoints=400)

        x = np.sin(angle)*distance
        y = np.cos(angle)*distance
    
        lidarData.setData(x,y)
        QtWidgets.QApplication.instance().processEvents()
        time.sleep(lidar_rate) #lidar_rate is set at the top of this example


    time.sleep(5)

    # Closing qlabs
    qlabs.close()
    print("Done!")


main()

Matlab Tutorial

Raw to download this tutorial: QCar Tutorial (.m).

% QCar Library Example
% -------------------------
% This example will show you how to spawn cars, and use the qvl library commands
% to control the car and its related functions.
% 
% .. note::
% 
%     Make sure you have Quanser Interactive Labs open before running this
%     example.  This example is designed to best be run in QCar Cityscape.


close all;
clear all;
clc;

% --------------------------------------------------------------
% Setting MATLAB Path for the libraries
% Always keep at the start, it will make sure it finds the correct references
newPathEntry = fullfile(getenv('QAL_DIR'), 'libraries', 'matlab', 'qvl');
pathCell = regexp(path, pathsep, 'split');
if ispc  % Windows is not case-sensitive
  onPath = any(strcmpi(newPathEntry, pathCell));
else
  onPath = any(strcmp(newPathEntry, pathCell));
end

if onPath == 0
    path(path, newPathEntry)
    savepath
end
% --------------------------------------------------------------

fprintf('\n\n----------------- Communications -------------------\n\n');

qlabs = QuanserInteractiveLabs();
connection_established = qlabs.open('localhost');

if connection_established == false
    disp("Failed to open connection.")
    return
end


disp('Connected')

num_destroyed = qlabs.destroy_all_spawned_actors();

fprintf('%d actors destroyed', num_destroyed);

% Use hSystem to set the tutorial title in the upper left of the qlabs window 
hSystem = QLabsSystem(qlabs);
hSystem.set_title_string('QCar Tutorial')

% Initialize QLabs
hCameraQCars = QLabsFreeCamera(qlabs);
hCameraQCars.spawn_id(1, [-15.075, 26.703, 6.074], [0, 0.564, -1.586]);
hCameraQCars.possess();

disp('---QCar---');

% Spawning the QCar with radians
hQCar0 = QLabsQCar(qlabs);
hQCar0.spawn_id(0, [-8.700, 14.643, 0.005], [0, 0, pi/2], 1);

% Spawn and destroy the existing QCar
hQCar1 = QLabsQCar(qlabs);
hQCar1.spawn_id(1, [-15.075, 26.703, 6.074], [0, 0, pi/2], 1);
hQCar1.destroy();

% Spawn a QCar with degrees
hQCar2 = QLabsQCar(qlabs);
x = hQCar2.spawn_id_degrees(2, [-11.048, 14.643, 0.005], [0, 0, 90], 1);

% Pinging the QCar
hQCar2.ping();



% Set the velocity and direction of the QCar in radians while also turning on the headlights and right turn signal
hQCar2.set_velocity_and_request_state(1, -pi/6, true, false, true, false, false);
pause(1);

% Set the velocity to 0 and direction of the QCar in radians while keeping the headlights on and right turn signal on
hQCar2.set_velocity_and_request_state(0.0, -pi/6, true, false, true, false, false);

% Set the velocity to 1 and direction of the QCar in degrees while keeping the headlights on and turning on the left turn signal
hQCar2.set_velocity_and_request_state_degrees(1, 30, true, true, false, false, false);
pause(1);

% Set the velocity to 0 and direction of the QCar in degrees while keeping the headlights on and left turn signal on
[success, location, rotation, frontHit, rearHit] = hQCar2.set_velocity_and_request_state_degrees(0.0, 30, true, true, false, false, false);

% Possess another QCar
x = hQCar2.possess();

pause(0.1);

% Set the velocity to 1 of the QCar in radians while keeping the headlights, brakeSignal and reverseSignal on
hQCar2.set_velocity_and_request_state(1, 0, true, true, true, true, true);
pause(1);

% Set the velocity to 0 while keeping the headlights, brakeSignal and reverseSignal on and turning on the left turn signal and right turn signal
hQCar2.set_velocity_and_request_state(0.0, 0, true, true, true, true, true);

% Turn all the lights off
hQCar2.set_velocity_and_request_state(0, 0, false, false, false, false, false);

% Car bumper test
hCameraQCars.possess();

% Change the camera view to see the bumper test
hCameraQCars.set_transform([-17.045, 32.589, 6.042], [0, 0.594, -1.568]);

% Spawn some shapes for our bumper test
hCubeQCarBlocks = QLabsBasicShape(qlabs);
hCubeQCarBlocks.spawn_id(100, [-11.919, 26.289, 0.5], [0, 0, 0], [1, 1, 1], hCubeQCarBlocks.SHAPE_CUBE, true);
hCubeQCarBlocks.spawn_id(101, [-19.919, 26.289, 0.5], [0, 0, 0], [1, 1, 1], hCubeQCarBlocks.SHAPE_CUBE, true);

% Create another QCar
hQCar3 = QLabsQCar(qlabs);
hQCar3.spawn_id(3, [-13.424, 26.299, 0.005], [0, 0, pi]);

% Have the QCar drive forward to hit the front block
for count = 1:10
    [x, location, rotation, frontHit, rearHit] = hQCar3.set_velocity_and_request_state(2, 0, false, false, false, false, false);
    pause(0.25);
end

% Put the QCar in ghost mode
hQCar3.ghost_mode();

% Have the QCar drive backwards to hit the back bumper
for count = 1:10
    [x, location, rotation, frontHit, rearHit] = hQCar3.set_velocity_and_request_state(-2, 0, false, false, false, false, false);
    pause(0.25);
end

% Change the color of ghost mode to red
hQCar3.ghost_mode(true, [1, 0, 0]);
pause(0.5);


% Set the velocity to 0 and turn all lights off
hQCar3.set_velocity_and_request_state(0, 0, false, false, false, false, false);

% Set the location of the QCar and request the state of the car. 
% If x== True and frontHit==True then the front bumper hit the block correctly.
[x, location, rotation, forward_vector, up_vector, frontHit, rearHit] = ...
    hQCar3.set_transform_and_request_state([-16.1, 26.299, 0.005], [0, 0, pi-0.01], ...
    true, false, false, false, false, false);
pause(0.5);

% Getting and saving the world transform of the QCar in Quanser Interactive Labs
[x, loc, rot, scale] = hQCar3.get_world_transform();

% Set the location of the QCar and request the state of the car.
% If x== True and rearHit==True then the back bumper hit the block correctly.
[x, location, rotation, forward_vector, up_vector, frontHit, rearHit] = ...
    hQCar3.set_transform_and_request_state_degrees([-13.1, 26.299, 0.005], ...
    [0, 0, 179], true, false, false, false, false, false);
pause(0.5);

% Turning off ghost mode for the QCar
hQCar3.ghost_mode(false, [1, 0, 0]);


% Possessing the overhead camera on the QCar
hQCar2.possess(hQCar2.CAMERA_OVERHEAD);
pause(0.5);

% Possessing the trailing camera on the QCar
hQCar2.possess(hQCar2.CAMERA_TRAILING);
pause(0.5);

% Possessing the front CSI camera on the QCar
hQCar2.possess(hQCar2.CAMERA_CSI_FRONT);
pause(0.5);

% Possessing the right CSI camera on the QCar
hQCar2.possess(hQCar2.CAMERA_CSI_RIGHT);
pause(0.5);

% Possessing the back CSI camera on the QCar
hQCar2.possess(hQCar2.CAMERA_CSI_BACK);
pause(0.5);

% Possessing the left CSI camera on the QCar
hQCar2.possess(hQCar2.CAMERA_CSI_LEFT);
pause(0.5);

% Possessing the front RealSense RGB camera on the QCar
hQCar2.possess(hQCar2.CAMERA_RGB);
pause(0.5);

% Possessing the RealSense depth camera on the QCar

hQCar2.possess(hQCar2.CAMERA_DEPTH);
pause(0.5);


% % Getting images from the different cameras
% [x, camera_image] = hQCar2.get_image(hQCar2.CAMERA_CSI_FRONT);
% [x, camera_image] = hQCar2.get_image(hQCar2.CAMERA_CSI_RIGHT);
% [x, camera_image] = hQCar2.get_image(hQCar2.CAMERA_CSI_BACK);
% [x, camera_image] = hQCar2.get_image(hQCar2.CAMERA_CSI_LEFT);
% [x, camera_image] = hQCar2.get_image(hQCar2.CAMERA_RGB);
% [x, camera_image] = hQCar2.get_image(hQCar2.CAMERA_DEPTH);


disp('LIDAR')

hQCar3.possess(hQCar3.CAMERA_OVERHEAD);

hFigure = figure();

disp('Reading from LIDAR... if QLabs crashes or output isn''t great, make sure FPS > 100')

% Have the QCar drive forward to hit the front block to show the live lidar.
% Speed can be changed by increasing or decreasing the value in the first
% parameter "forward" 
hQCar3.set_velocity_and_request_state(1, 0, false, false, false, false, false);
lidar_rate = 0.05;

for count = 0:25

    [success, angle, distance] = hQCar3.get_lidar(400);

    x = sin(angle).*distance;
    y = cos(angle).*distance;

    plot(x,y, '.');
    axis([-60 60 -60 60]);
    drawnow;
    pause(lidar_rate);
    
end

pause(5);

% Closing qlabs
qlabs.close();
disp('Done!');
close(hFigure);