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V-REP robotic simulator, installation and Python API

V-REP is a powerful cross-platform 3D simulator based on a distributed control architecture: control programs (or scripts) can be directly attached to scene objects and run simultaneously in a threaded or non-threaded fashion. It features advanced physics engines which allows to simulate real-world physics and object interactions (collisions, object dynamics, etc.).

V-REP installation

V-REP is cross-platform and works on Windows, Linux and macOS. Download the educational version V-REP Pro EDU for your particular system.

On Linux
- Download the archive .tar.gz, unpack it, navigate to the unpacked directory in the terminal and run the simulator calling the script: ./vrep.sh
On Windows
- Download the .exe installation file, run it and follow the instructions in the installer. Most likely you will be prompted to install Visual C Redistributable package. You can run the V-REP simulator by launching the vrep from desktop. When running V-REP you may see a firewall or antivirus popup as the V-REP simulator uses UDP and TCP/IP sockets for communication which is okay.
On macOS
- Download the archive .zip, unpack it, navigate to the unpacked directory and run the simulator by launching vrep

V-REP python remote API

V-REP supports multiple ways of simulation control including internal Lua scripting, ROS connectivity or external API. The documentation for external API functions can be found in:
V-REP Python remote API documentation
V-REP C++ remote API documentation

Tutorial on basic interfacing between V-REP and python can be found on the web: V-REP Python remote API tutorial

When using the connection through remote API, it is necessary to include the V-REP remote API binding scripts and library located at the installation directory of the V-REP in:
./programming/remotaApiBindings/python/python - the scripts
./programming/remotaApiBindings/lib/lib - the library
It is necessary to copy all the sources within these two directories and include them in the python script.

Labs Python Scripts

The python scripts for controlling the robot in V-REP used in during the labs are for python version 2.7. Besides, they rely on python libraries that help to solve the lab tasks. The required libraries are already installed on the lab computers, but they can be install using, e.g.,

sudo apt install python-numpy python-scipy python-matplotlib ipython ipython-notebook python-pandas python-sympy python-nose

Further, the scripts for controlling the hexapod rely on the provided hardware abstraction layer, in particular for V-REP hexapod_vrep. The libraries must be accessible to your python scripts, and thus you can added (or symlink) them to the working directory. However, it is more easier to setup your working environment and the library to the search path. This can be done, e.g., in .bashrc. For example, let suppose the hexapod_vrep is in $HOME/uir/. Then, you can added it to search path by

export PYTHONPATH=$PYHTONPATH:$HOME/uir:$HOME/uir/hexapod_vrep/vrep_api

Besides, the scripts use python2.7, while the default version is python 3 in ubuntu 16.04. Therefore, you can use alias to python e.g.,

alias python=python2.7

and specify the python interpret in the scripts files by the first line as

#!/usr/bin/env python

Notice, using env is platform independent as it can be in various directories.

Finally, you can set the execution flag of the scripts using, e.g.,

chmod +x lab01.py

and enjoy a directly executable scripts. So, your .bashrc can contain some thing like

alias python=python2.7
export PYTHONPATH=$HOME/uir:$HOME/uir/hexapod_vrep/vrep_api
export PATH=$PATH:$HOME/uir/V-REP_PRO_EDU_V3_4_0_Linux