Server Example: Material Static Friction

Overview

Compares static and dynamic friction by pushing a box across a ground plane. Material properties are loaded from XML to demonstrate material file usage.

Screenshot

Binary

CMake target and executable name: material_static_friction.

Run

Build and run from your build directory:

cmake --build . --target material_static_friction
./material_static_friction

On Windows, run material_static_friction.exe instead. This example uses RaisimServer. Start a visualizer client (RaisimUnity, RaisimUnreal, or the rayrai TCP viewer) and connect to port 8080.

Details

• Applies constant force to a box to show static vs dynamic friction.

• Loads material properties from an XML file.

• Prints console hints when friction regime changes.

Source

// This file is part of RaiSim. You must obtain a valid license from RaiSim Tech
// Inc. prior to usage.

#include "raisim/RaisimServer.hpp"
#include "raisim/World.hpp"
#include "rayrai_tcp_viewer_hint.hpp"

int main(int argc, char* argv[]) {
  auto binaryPath = raisim::Path::setFromArgv(argv[0]);

  /// create raisim world
  raisim::World world;
  world.setTimeStep(0.001);

  /// create objects
  auto box = world.addBox(1,1,1,1,"steel");
  auto ground = world.addGround(0, "brass");
  box->setPosition(0,0,0.499);

  /// option 1: use cpp api to define the materials
//  world.setMaterialPairProp("steel", "brass", 0.2, 0., 0., 0.95, 0.01);
  /// option 2: use the material xml file
  world.updateMaterialProp(raisim::MaterialManager(binaryPath.getDirectory() + "\\rsc\\testMaterials.xml"));

  /// launch raisim server
  raisim::RaisimServer server(&world);
  server.launchServer();
  raisim_examples::warnIfNoClientConnected(server);
  server.focusOn(box);

  std::cout<<"static friction is active because the initial velocity is too low."<<std::endl;
  for (int i = 0; i < 5000; i++) {
    raisim::MSLEEP(1);
    box->setExternalForce(0, {5, 0, 0});
    server.integrateWorldThreadSafe();
  }

  box->setLinearVelocity({0.01, 0, 0});
  std::cout<<"now dynamic friction is active"<<std::endl;

  for (int i = 0; i < 5000; i++) {
    RS_TIMED_LOOP(int(world.getTimeStep()*1e6))
    box->setExternalForce(0, {5, 0, 0});
    server.integrateWorldThreadSafe();
  }

  server.killServer();
}