movln.rst

Simulation Environment Document

Download Simulator

First download the simulator and unzip it.

Launch Simulator

Devices with graphical interfaces

You just need to run the appropriate executable file in windows or Linux.

In windows: Run the GrabSimClient.exe executable.

In Linux:

bash /path/to/LinuxClient/GrabSimClient.sh

Devices without graphical interfaces [1]

Verifying GitHub Access

Verify that you can access the Unreal Engine source code repository on GitHub: https://github.com/EpicGames/UnrealEngine. If you cannot access the repository then you will need to link your GitHub account with your Epic Games Account.

Authenticating with GitHub Container Registry

To download container images from GitHub Container Registry using Docker you will need to authenticate using a personal access token. If you do not already have a personal access token with the read:packages scope then you will need to follow the steps to create one.

Once you have created a personal access token with the required scope, use the docker login command to authenticate with GitHub Container Registry as described in the instructions from GitHub. This command will need to be run from the command-line interface。

Once you have opened the command-line prompt then run the command shown below, replacing ACCESS_TOKEN with your personal access token and USERNAME with your GitHub username:

echo ACCESS_TOKEN | docker login ghcr.io -u USERNAME --password-stdin

If the authentication process was successful then you should see the message “Login Succeeded” displayed.

Pulling Prebuilt Container Images

The official prebuilt container images for Unreal Engine are stored as image tags in the ghcr.io/epicgames/unreal-engine repository. To download the Linux development image for Unreal Engine 4.27, use the docker pull command shown below:

docker pull ghcr.io/epicgames/unreal-engine:dev-4.27

This will download a container image that encapsulates the files for Unreal Editor and build tools, which are quite large. Depending on the speed of your internet connection, the download process may take some time. When the download is complete, you should see the message “Status: Downloaded newer image for ghcr.io/epicgames/unreal-engine:dev-4.27” displayed.

Building the Container

You need to make sure you have sufficient permissions on the LinuxClient:

cd LinuxClient
chmod -R 775 Engine
chmod -R 775 GrabSim
chmod 777 GrabSimClient.sh

Use the following docker file code to create a new one to run.

FROM ghcr.io/epicgames/unreal-engine:runtime-pixel-streaming

COPY --chown=ue5:ue5 LinuxClient path/to/LinuxClient

ENV NVIDIA_DRIVER_CAPABILITIES all

ENTRYPOINT ["bin/bash", "/path/to/LinuxClient/GrabSimClient.sh", "-RenderOffScreen"]
CMD []

After creating the container you can enter as root if needed:

docker exec -it -u root YOUR_CONTAINER /bin/bash

To exit the container, run the command shown below:

exit

Note that our simulator runs in a docker container and occupies port 30001. If you want to map to other ports(eg. port 30020) on the host and control the simulator on the server, you need to build the container with the following command:

nvidia-docker run --privileged -it --gpus='"device=1"' -p 30020:30001 --name sim30020 -v /YOUR/Mount/FOLDER:/home YOUR_BUILDED_IMAGE /bin/bash

cd /PATH/TO/LinuxClient
bash GrabSim.sh -RenderOffScreen

Communication Protocol

• Protocol: gRPC
• Port: 30001

Data Types

Only the data type is introduced, please refer to the interface method section for interface details.

Count

Used for initword( In version 1)

F i e l d	T y p e	V a l u e	Description
v a l u e	i n t 3 2	( 0 )	Number of scenes in world. Means num_processes. Usually set to 1

Usage:

GrabSim_pb2.Count(value=1)

BatchMap

Used for initword( In version 2)

F i e l d	T y p e	Va lue	Description
c o u n t	i n t 3 2		Number of scenes in world. Means num_processes. Usually set to 1
m a p I D	i n t 3 2	3 ,4, 5	Meaning of mapID: 3 : Coffee 4 : Restaurant 5 : Nurse home

Usage:

GrabSim_pb2.BatchMap(count=1, mapID=3)

Nothing

No content, used when interface does not need input or output values.( in version 1)

Usage:

GrabSim_pb2.Nothing()

NUL

No content, used when interface does not need input or output values. Equal to the Data Type: Nothing. (in version 2)

Usage:

GrabSim_pb2.NUL()

SceneID

F i e l d	T y p e	V a l u e	Description
v a l u e	i n t 3 2	( 0 )	Scene ID. The desirable range is [0, Count-1]. Default is 0

Usage:

GrabSim_pb2.SceneID(value=0)

World

Field	Type	Description
scenes	list/Scene	All scenes in world
error	string	Partial error information from execution

ResetParams

Field	Type	Value	Description
scene	int32		Target scene ID
adjust	bool	(False)	Set to True for init params to take effect
height	float	78.5~111.5	(90.4) Table height
width	float	50~150	(107.4) Table width

Usage:

GrabSim_pb2.ResetParams()

Object

Field	Type	Description
name	string	Object name
location	Location	Object position
rotation	Rotation	Object rotation

Usage:

GrabSim_pb2.Object(name = "AA",type =
"ADMilk",location = GrabSim_pb2.Location(X=30,Y=-260,Z=84))

Location

Field	Type	Description
X	float	X coordinate
Y	float	Y coordinate
Z	float	Z coordinate

Usage:

GrabSim_pb2.Location(X=30,Y=-260,Z=84)

Rotation

Field	Type	Description
angle	float	Rotation angle in degrees

MakeObjects

F ield	Type	V alue	Description
s cene	int32		Target scene ID
ap pend	bool	(Fa lse)	Set to append objects or clear existing ones
obj ects	lis t/Object		List of objects

ObjectList.Object

Field	Type	Value	Description
x, y	float		Object position, height at table top
type	int		Object ID

RemoveObjects

Field	Type	Value	Description
scene	int32		Target scene ID
objectIDs	list/int32		Index of objects in Scene.Objects

Action

F i e l d	Ty pe	Value	Description
s c e n e	i nt 32		Target scene ID
a c t i o n	en um	Gr abSim_pb2.Action.ActionType. WalkToGrabSim_pb2.Action.Act ionType.GraspGrabSim_pb2.Act ion.ActionType.ReleaseGrabSi m_pb2.Action.ActionType.Move	WalkTo: Adjust robot position, 5 params Grasp: Control grasping, left/right hand in valuesRelease: Control releasing, left/right hand in values Move: Control joint angles, 21 params in values
v a l u e s	li st /f lo at	([0, …])	WalkTo: Adjust robot position, 5 paramsX, Y, Yaw, 0/-1/1, distance: If it cannot be reached, it will find the target within 10 cm# 0: Query only, not move # -1: Teleport to target position # 1: Navigation to target position

Usage:

GrabSim_pb2.Action(
            scene=0,
            action=GrabSim_pb2.Action.ActionType.WalkTo,
            values=[location[0], location[1], location[2], -1, 10]
        )

Joint

Field	Type	Description
name	string	Joint name
location	Location	Joint position
rotation	Rotation	Joint rotation

Usage:

GrabSim_pb2.Joint(name="joint1", location=Location(1.0, 2.0, 3.0), rotation=Rotation(45))

Scene

F ield	Type	Description
sce neID	int32	Scene ID
loca tion	Location	Robot coordinates (center of workspace, Scene coordinate system)
rota tion	Rotation	Robot rotation angles
jo ints	list/ Scene.Joint	Pose information for robot joints
fin gers	list/S cene.Finger	Pose information for robot finger joints
obj ects	list/S cene.Object	Position and info of all objects in scene. First object is table, last few are hands with no position info
t imes tamp	int64	Nanoseconds since 1970/1/1
e rror	string	Partial error information from execution

Usage:

import numpy as np
p_x, p_y = scene.location.X, scene.location.Y
yaw = scene.rotation.Yaw * np.pi / 180

scene = stub.Observe(GrabSim_pb2.SceneID(value=0))
print('------------------show_env_info----------------------')
print(
    f"location:{[scene.location.X, scene.location.Y]}, rotation:{scene.rotation.Yaw}\n",
    f"joints number:{len(scene.joints)}, fingers number:{len(scene.fingers)}\n", f"objects number: {len(scene.objects)}\n"
    f"rotation:{scene.rotation}, timestep:{scene.timestep}\n"
    f"timestamp:{scene.timestamp}, collision:{scene.collision}, info:{scene.info}")

Scene.Joint

Field	Type	Description
name	string	Joint name
location	Location	Joint position
angle	float	Joint angle

Scene.Finger

Field	Type	Description
name	string	Finger name
location	list/Location	Position of each joint of the finger
angle	float	Joint angle

Scene.Object

Field	Type	Description
name	string	Object name
location	Location	Object position
rotation	Rotation	Object rotation angle (-180, 180)
boxes	list/Object.Box.Diagonal	Bounding boxes of object

Usage:

GrabSim_pb2.Scene.Object([{'name': 'NFCJuice', 'location': [2525, 2510], 'angle': [0, 0, 0]}])

Pose

Field	Type	Description
timestamp	int64	Timestamp in nanoseconds
joints	listJoint	Robot joint poses

Usage:

GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=180)

MakeObjects

F ield	Type	V alue	Description
s cene	int32		Target scene ID
ap pend	bool	(Fa lse)	Set to append objects or clear existing ones
obj ects	lis t/Object		List of objects

ObjectList.Object

Field	Type	Value	Description
x, y	float		Object position, height at table top
type	int		Object ID

RemoveObjects

Field	Type	Value	Description
sceneID	int32		Target scene ID
objectIDs	list/int32		Index of objects in Scene.Objects

Move

Field	Type	Description
x	float	Robot x coordinate
y	float	Robot y coordinate
angle	float	Robot current angle
speed	float	Robot moving speed in facing direction, cm/s
rotating	float	Robot rotation speed, degrees/s, positive is clockwise

CameraList

Field	Type	Description
sceneID	int32	Target scene ID
cameras	list/enum	CameraName

CameraName:

• Head_Color: Head RGB camera

• Head_Depth: Head depth camera

• Head_Segment: Head Segment camera

• Chest_Color: Chest RGB camera

• Waist_Color: Waist RGB camera

• Waist_Depth: Waist depth camera

  Usage:

GrabSim_pb2.CameraList(scene=0, cameras=[
    GrabSim_pb2.CameraName.Head_Depth, GrabSim_pb2.CameraName.Head_Color,
    GrabSim_pb2.CameraName.Head_Segment
])

CameraData

Field	Type	Description
images	list/CameraData.Image	Image data
timestamp	int64	Nanoseconds since 1970/1/1

CameraData.Image

Field	Type	Description
name	string	Camera name
data	bytes	Byte array
dtype	string	Data format (uint8, float16, etc)
location	Location	Camera position
rotation	Rotation	Camera rotation angles
width	int	Image width
height	int	Image height
channels	int	Number of channels
parameters	CamaraData.Image.Parameters	Camera intrinsics

CameraData.Image.Parameters

F ie ld	Type	Description
fx	float
fy	float
cx	float
cy	float
ma tr ix	arra y/float	Transform matrix from camera to robot coordinates (4x4, flattened)

WalkerList

Field	Type	Description
walkers	list/enum	walker_list can be appended through WalkerList.Walker
scene	int32	Target scene ID

Usage:

walker_list.append(GrabSim_pb2.WalkerList.Walker(id=i, pose=GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=90)))
GrabSim_pb2.WalkerList(walkers=walker_list, scene=0)

WalkerList.Walker

Field	Type	Description
id	int32	The serial number of the walker to join. From 0
pose	GrabSim_pb2.Pose	X, Y, Yaw

Usage:

GrabSim_pb2.WalkerList.Walker(id=i, pose=GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=90))

WalkerControls

F ield	Type	Description
cont rols	list /enum	controls_list can be appended through WalkerControls.WControl
s cene	int32	Target scene ID

Usage:

controls.append(GrabSim_pb2.WalkerControls.WControl(id=i, autowalk=is_autowalk, speed=200, pose=pose))
GrabSim_pb2.WalkerControls(controls=controls, scene=0)

WalkerControls.WControl

Field	Type	Description
id	int32	The joined walker’s serial number.
autowalk	str	Usually set to is_autowalk.
speed	int32	The speed to move. (cm/s)
pose	GrabSim_pb2.Pose	X, Y, Yaw

Usage:

GrabSim_pb2.WalkerControls.WControl(id=i, autowalk=is_autowalk, speed=200, pose=pose)

RemoveList

Field	Type	Description
IDs	list/enum	The joined walker’s serial number.
scene	int32	Target scene ID

Usage:

GrabSim_pb2.RemoveList(IDs=[1, 3], scene=scene_id)

Interface Methods

First you need to do

Install grpc environment

pip install grpcio

You need to download GrabSim_pb2_grpc.py and GrabSim_pb2.py corresponding to the simulator version. Then import them.

import grpc
import GrabSim_pb2_grpc
import GrabSim_pb2

Define the channel

Define information such as ports to communicate with the simulator. If you run the simulator on other machines, please change localhost to the IP address of the machine, and make sure your machine can access port 30001.

channel = grpc.insecure_channel('localhost:30001',options=[
            ('grpc.max_send_message_length', 1024*1024*1024),
            ('grpc.max_receive_message_length', 1024*1024*1024)
        ])

If you mapped the port before (e.g. mapped to port 30020), you can run directly on the server without entering the container (but keep the container running):

channel = grpc.insecure_channel('localhost:30020',options=[
            ('grpc.max_send_message_length', 1024*1024*1024),
            ('grpc.max_receive_message_length', 1024*1024*1024)
        ])

Create a client

Create a client。

Request: Channel

Response: Scene - initial scene state

Usage:

stub = GrabSim_pb2_grpc.GrabSimStub(channel)

Init

Initialize the simulation environment. ( In version 1)

Request: Channel

Response: Scene - initial scene state

Usage:

initworld = stub.Init(GrabSim_pb2.Count(value=1))
scene = initworld.scenes[0]

SetWorld

Initialize the simulation environment. (In version 2)

Request: count - number of scenes to initialize.

​Meaning of mapID:

​3 : Coffee

​4 : Restaurant

​5 : Nurse home

Response: Scene - initial scene state

Usage:

initworld = stub.SetWorld(GrabSim_pb2.BatchMap(count=1, mapID=4))
scene = initworld.scenes[0]

your can get the object type in the scenes

obj_list = set()
area_list = set()
for i in range(len(scene.objects)):
    object = scene.objects[i]
    name = object.name
    if 'Room' in name:
        obj_list.add(name)
    else:
        area_list.add(name)
print(obj_list)
print(area_list)

Reset

Reset a scene.

Request: ResetParams

Response: Scene - reset scene state

Usage:

reset_response = stub.Reset(GrabSim_pb2.ResetParams(scene=0))

Observe

Get object and robot poses in the scene.

Request: SceneID

Response: Scene

Usage:

scene = stub.Observe(GrabSim_pb2.SceneID(value=0))
objects = scene.objects

ObservePose

Get the position and angle of each joint of the robot

Request: SceneID

Response: Scene

Usage:

pose = stub.ObservePose(GrabSim_pb2.SceneID(value=0))

Capture

There are 3 cameras on the head of the robot in the simulator, which are depth and segmentation cameras. You can also specify the cameras of other parts of the robot (eg. Chest_Color/Waist_Color/Waist_Depth). See the Data Types section/CamerList for details.

Request: SceneID

Response: Scene

Usage:

images = stub.Capture(GrabSim_pb2.CameraList(sceneID=0, cameras=[
    GrabSim_pb2.CameraName.Head_Depth, GrabSim_pb2.CameraName.Head_Color,
    GrabSim_pb2.CameraName.Head_Segment
])).images

depth = np.frombuffer(images[0].data, dtype=images[0].dtype).reshape(
    (images[0].height, images[0].width, images[0].channels))
rgb = np.frombuffer(images[1].data, dtype=images[1].dtype).reshape(
    (images[1].height, images[1].width, images[1].channels))
# convert to BGR format
rgb = rgb[:, :, [2, 1, 0]]

Do

Execute an action in the scene. Support WalkTo, Grasp, Release, Move actions. See the Data Types section/Action for details.

Flexible angle and can walk to any reachable area. In VLN tasks, when executing the predicted action, you can customize the rotation angle and displacement distance corresponding to each action.

Request: Action

Response: Scene - updated scene state

Usage:

Navigate to (-650.0, -1550.0, -15.0), if you can’t reach it, you will find the target within 10 cm

Scene = stub.Do(GrabSim_pb2.Action(
    scene=0,
    action = GrabSim_pb2.Action.ActionType.WalkTo,
    values = [ -650.0, -1550.0,-15.0,-1,10]
))

GenerateObject

Generate an object in the scene. You can add object in the specified position you need.

Request: ObjectList

Response: Scene - updated scene with object

Usage:

obj_list = [GrabSim_pb2.ObjectList.Object(X=25, Y=2, Yaw=15, Z=100, type=0)]
scene = stub.MakeObjects(GrabSim_pb2.ObjectList(objects=obj_list, scene=4))

Create an item of type “ADMilk” at the coordinates (X=30, Y=-260, Z=84)

scene = stub.GenerateObject(GrabSim_pb2.Object(name = "AA",type =
6,location = GrabSim_pb2_pb2.Location(X=30,Y=-260,Z=84)))

AcquireWalkers

Query the model category of all walkers.

Request: Nothing

Response: model category of all walkers.

Usage:

print(stub.AcquireWalkers(GrabSim_pb2.NUL()))

All walker model categories to the appendix for details. We provide 52 categories of walker models with different appearances.

AddWalker

Add walkers to the scene.

Request: WalkerList - list of walkers to add

Response: Scene - updated scene with walkers

Usage:

updated_scene = stub.AddWalker(GrabSim_pb2.WalkerList(walkers=[walker1, walker2]))

Add 4 walkers at specified positions to the scene and update the scene:

scene = stub.Observe(GrabSim_pb2.SceneID(value=0))

walker_loc = [[120, -500], [-35, -385], [115, -360], [50,-392]]
walker_list = []
for i in range(len(walker_loc)):
    loc = walker_loc[i]
    action = GrabSim_pb2.Action(scene=0, action=GrabSim_pb2.Action.ActionType.WalkTo,
                                values=[loc[0], loc[1], 0, 0, 0])
    scene = sim_client.Do(action)
    print(scene.info)
    walker_list.append(GrabSim_pb2.WalkerList.Walker(id=i, pose=GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=90)))
scene = stub.AddWalker(GrabSim_pb2.WalkerList(walkers=walker_list, scene=0))

ControlWalkers

Control walker movements.

Request: WalkerControls - controls for each walker

Response: Scene - updated scene with walker positions

Usage:

updated_scene = stub.ControlWalkers(GrabSim_pb2.WalkerControls(controls=[control1, control2]))

Designate 4 walkers to go to the designated location respectively, using ControlWalkers will formulate the route and move according to the designated pose and speed.

scene = stub.Observe(GrabSim_pb2.SceneID(value=0))

walker_loc = [[95, 140], [93, -356], [123, 400], [97,-381]]
controls = []
for i in range(len(scene.walkers)):
    loc = walker_loc[i]
    is_autowalk = True
    pose = GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=180)
    controls.append(GrabSim_pb2.WalkerControls.WControl(id=i, autowalk=is_autowalk, speed=200, pose=pose))
scene = stub.ControlWalkers(GrabSim_pb2.WalkerControls(controls=controls, scene=0))

RemoveWalkers

Remove walkers from the scene.

Request: RemoveList - IDs of walkers to remove

Response: Scene - updated scene without removed walkers / delete specific walkers.

Usage:

updated_scene = stub.RemoveWalkers(GrabSim_pb2.RemoveList(walker_ids=[1, 2]))

Remove the walker and update the scene:

scene = stub.Observe(GrabSim_pb2.SceneID(value=scene_id))
# print(scene.walkers)
scene = stub.RemoveWalkers(GrabSim_pb2.RemoveList(IDs=[1, 3], scene=scene_id))

CleanWalkers

Remove all walkers from the scene.

Request: SceneID

Response: Scene - updated scene without walkers / delete all walkers.

Usage:

update_scene = stub.CleanWalkers(GrabSim_pb2.SceneID(value=0))

BindCommand

Receive commands from the grpc server through BindCommand binding, such as clicking the record button in the VR scene, you will receive the “record” command

Request: SceneID

Response: Nothing

Usage:

for cmd in stub.BindCommand(GrabSim_pb2.SceneID(value=0)):
     print(cmd)

demo

easy beginning for Vision and Language navigation

from google.protobuf import message
import grpc
import numpy as np
import cv2
import matplotlib.pyplot as plt

import GrabSim_pb2_grpc
import GrabSim_pb2

channel = grpc.insecure_channel('localhost:30001',options=[
            ('grpc.max_send_message_length', 1024*1024*1024),
            ('grpc.max_receive_message_length', 1024*1024*1024)
        ])  # define the channel

stub = GrabSim_pb2_grpc.GrabSimStub(channel) # create a client
initworld = stub.SetWorld(GrabSim_pb2.BatchMap(count=4, mapID=3)) # init the world and creat 4 scenes(Caffe)

for i in range(len(initworld.scenes)):
    scene=initworld.scenes[i] # choose the world's scenes[i] and print agent's location in the scene
    print("scene %d, ginger location (%d,%d) direction %d"%(i,scene.location.X,scene.location.Y,scene.rotation.Yaw))
    for j in range(len(initworld.scenes[i].objects)): # get the object and location in the scene
        object = scene.objects[j]
        print("scene %d, object %d: name %s, location (%d,%d,%d)"%(i,j,object.name,object.location.X,object.location.Y,object.location.Z))

    scene = stub.Do(GrabSim_pb2.Action(scene=i, action=GrabSim_pb2.Action.WalkTo, values=[-500, 100, 90, -1, 10]))
    # the agent naviagtion to (-500, 100, 90) and update scene.
    print("scene %d, ginger moved to location %d,%d direction %d"%(i,scene.location.X,scene.location.Y,scene.rotation.Yaw))

message = stub.Capture(GrabSim_pb2.CameraList(scene=0, cameras=[GrabSim_pb2.CameraName.Head_Depth, GrabSim_pb2.CameraName.Head_Color])) # use the carmer in agent's head to get observation(depth, RGB, segmentation)
images = message.images

depth = np.frombuffer(images[0].data, dtype=images[0].dtype).reshape(
    (images[0].height, images[0].width, images[0].channels))
rgb = np.frombuffer(images[1].data, dtype=images[1].dtype).reshape(
    (images[1].height, images[1].width, images[1].channels))
seg = np.frombuffer(images[0].data, dtype=images[0].dtype).reshape(
    (images[0].height, images[0].width, images[0].channels))
items = message.info.split(';')
seg_object_names = {}
     for item in items:
        key, value = item.split(':')
        seg_object_names[int(key)] = value
# convert to BGR format
rgb = rgb[:, :, [2, 1, 0]]

scene = stub.Reset(GrabSim_pb2.ResetParams(scene=0)) # reset scene[0] in the world

add objects in simulator

import grpc
import GrabSim_pb2_grpc
import GrabSim_pb2

channel = grpc.insecure_channel('localhost:30001',options=[
            ('grpc.max_send_message_length', 1024*1024*1024),
            ('grpc.max_receive_message_length', 1024*1024*1024)
        ])  # define the channel

stub = GrabSim_pb2_grpc.GrabSimStub(channel) # create a client
initworld = stub.SetWorld(GrabSim_pb2.BatchMap(count=1, mapID=3)) # set world
scene = initworld.scenes[0] # choose scene

obj_list = [GrabSim_pb2.ObjectList.Object(X=25, Y=2, Yaw=15, Z=100, type="Mug")]
scene = stub.MakeObjects(GrabSim_pb2.ObjectList(objects=obj_list, scene=0))
objects = scene.objects

add walkers in simulator

import grpc
import GrabSim_pb2_grpc
import GrabSim_pb2

channel = grpc.insecure_channel('localhost:30001',options=[
            ('grpc.max_send_message_length', 1024*1024*1024),
            ('grpc.max_receive_message_length', 1024*1024*1024)
        ])  # define the channel

stub = GrabSim_pb2_grpc.GrabSimStub(channel) # create a client
initworld = stub.SetWorld(GrabSim_pb2.BatchMap(count=1, mapID=3)) # set world
scene = stub.Observe(GrabSim_pb2.SceneID(value=0))

# acquire walkers
print(stub.AcquireWalkers(GrabSim_pb2.NUL()))

# add walkers
walker_loc = [[120, -500], [-35, -385], [115, -360], [50,-392]]
walker_list = []
for i in range(len(walker_loc)):
    loc = walker_loc[i]
    action = GrabSim_pb2.Action(scene=0, action=GrabSim_pb2.Action.ActionType.WalkTo,
                                values=[loc[0], loc[1], 0, 0, 0])
    scene = sim_client.Do(action)
    print(scene.info)
    walker_list.append(GrabSim_pb2.WalkerList.Walker(id=i, pose=GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=90)))
scene = stub.AddWalker(GrabSim_pb2.WalkerList(walkers=walker_list, scene=0))

# control walkers
walker_loc = [[95, 140], [93, -356], [123, 400], [97,-381]]
controls = []
for i in range(len(scene.walkers)):
    loc = walker_loc[i]
    is_autowalk = True
    pose = GrabSim_pb2.Pose(X=loc[0], Y=loc[1], Yaw=180)
    controls.append(GrabSim_pb2.WalkerControls.WControl(id=i, autowalk=is_autowalk, speed=200, pose=pose))
scene = stub.ControlWalkers(GrabSim_pb2.WalkerControls(controls=controls, scene=0))

# remove walkers
print(scene.walkers)
scene = stub.RemoveWalkers(GrabSim_pb2.RemoveList(IDs=[1, 3], scene=0))
print(scene.walkers)

# clean walkers
scene = stub.CleanWalkers(GrabSim_pb2.SceneID(value=0))

The walker’s start location and target location must be reachable. Otherwise the the scene.info will be unreachable. You can test whether the target location is reachable by the following method:

msg = stub.Do(GrabSim_pb2.Action(
    action = GrabSim_pb2.Action.WalkTo,
    values = [-2150,-1350,-100, 0, 10]
    # 0: Query only, not move
    # -1: Teleport to target position
    # 1: Navigation to target position
))
print(msg.info)

appendix

List of scenes

map id : 1 – Separate Tables

img

map id : 2 – Indoor Scene

img

map id : 3 – Coffee

img

map id : 4 – Restaurant

img

map id : 5 – Nursing Room

img

List of objects inherent to the scene

Coffee

Item
apple
Cake
Drinks
Glass
Saucer
Door
Knife
Machine
Bread
Mug
Packaged Coffee
Spoon
Cube Sugar
Tray
Straw
Drink
Take-Away Cup
Tongs
Vacuum
Trash Bin

Restaurant

Item
Room-Elevator
Room-Dining
Room-Bar
Room-Drinking
Room-Lobby
Cake
Plate
Drinking Machine
Bread
Red Bull Drink
Alcoholic Drink
Kettle
Fork
Knife
Alcoholic Drink (Bulk)
Trolley
Table
Chair
Teapot
Glass
Teacup
Dixie Cup
Tongs

Nursing Room

Item
Monitor
Curtain
Knife
Pot
Disc
Plants
Elevator
Elevator Panel
Trash Bin
Door
Chair
Desk
Chess
WheelChair
Gate
Case
Front Desk
Closet
Sofa
TV
Books
Medicine
Armrest
Table
Cloth
Fridge
Plant
Teapot
Microwave
EmergencyKit
Bed
Fruit

Controllable list Walker’s model categories(total 50 categories of walkers)

Type
walker: “Boy01”	walker: “Boy02”	walker: “Boy03”
walker: “Boy Euro01”
walker: “ Girl01”	walker: “ Girl02”	walker: “Girl03”
walker: “Girl Euro01”
walker: “ Male01”	walker: “ Male02”	walker: “Male03”
walker: “Male Afro01”	walker: “Male Afro02”
walker: “MaleAf roOw01”
walker: “Male Amer01”	walker: “Male Amer02”	walker: “Mal eAmer03”	w alker: “MaleA mer04”
walker: “Male Asia01”	walker: “Male Asia02”
walker: “MaleAs iaOw01”	walker: “MaleAs iaOw02”	walker: “MaleAsi aOwOw03”
walker: “Male Euro01”	walker: “Male Euro02”
walker: “MaleEu roOw01”	walker: “MaleEu roOw02”
walker: “Fe male01”	walker: “Fe male02”	walker: “F emale03”	w alker: “Fem ale04”	walke r:“Fem ale05”	walke r:“Fem ale06”
walker: “Female Afro01”	walker: “Female Afro02”	walke r:“Femal eAfro03”	w alker: “F emaleA fro04”	w alker: “F emaleA fro05”	w alker: “F emaleA fro06”	w alker: “F emaleA fro07”
walker: “F emaleAf roOw01”	walker: “F emaleAf roOw02”	walker: “FemaleA froOw03”
walker: “Female Asia01”	walker: “Female Asia02”	walker: “Femal eEuro01”	w alker: “F emaleE uro02”
walker: “F emaleEu roOw01”	walker: “F emaleEu roOw02”	walker: “FemaleE uroOw03”

List of controllable generated objects

img

ID	Name
0	Mug
1	Banana
2	Toothpaste
3	Bread
4	Softdrink
5	Yogurt
6	ADMilk
7	VacuumCup
8	Bernachon
9	BottledDrink
10	PencilVase
11	Teacup
12	Caddy
13	Dictionary
14	Cake
15	Date
16	Stapler
17	LunchBox
18	Bracelet
19	MilkDrink
20	CocountWater
21	Walnut
22	HamSausage
23	GlueStick
24	AdhensiveTape
25	Calculator
26	Chess
27	Orange
28	Glass
29	Washbowl
30	Durian
31	Gum
32	Towl
33	OrangeJuice
34	Cardcase
35	RubikCube
36	StickyNotes
37	NFCJuice
38	SpringWater
39	Apple
40	Coffee
41	Gauze
42	Mangosteen
43	SesameSeedCake
44	Glove
45	Mouse
46	Kettle
47	Atomize
48	Chips
49	SpongeGourd
50	Garlic
51	Potato
52	Tray
53	Hemomanometer
54	TennisBall
55	ToyDog
56	ToyBear
57	TeaTray
58	Sock
59	Scarf
60	ToiletPaper
61	Milk
62	Soap
63	Novel
64	Watermelon
65	Tomato
66	CleansingFoam
67	CocountMilk
68	SugarlessGum
69	MedicalAdhensiveTape
70	SourMilkDrink
71	PaperCup
72	Tissue

Joint Information

Action.values param	Name
0	Knee_X_Anchorn
1	Back_Z_Anchorn
2	Back_X_Anchorn
3	Back_Y_Anchorn
4	Neck_Z_Anchorn
5	Neck_X_Anchorn
6	Head_Y_Anchorn
7	LShlouder_X_Anchorn
8	LShlouder_Y_Anchorn
9	LElbow_Z_Anchorn
10	LElbow_X_Anchorn
11	LWrist_Z_Anchorn
12	LWrist_X_Anchorn
13	LWrist_Y_Anchorn
14	RShlouder_X_Anchorn
15	RShlouder_Y_Anchorn
16	RElbow_Z_Anchorn
17	RElbow_X_Anchorn
18	RWrist_Z_Anchorn
19	RWrist_X_Anchorn
20	RWrist_Y_Anchorn

[1]	https://docs.unrealengine.com/5.0/en-US/quick-start-guide-for-using-container-images-in-unreal-engine/