stepSimulation in b3RobotSimulatorClientAPI_NoDirect and btDiscreteDynamicsWorld

[Evi5]

stepSimulation of b3RobotSimulatorClientAPI_NoDirect running slowly

stepSimulation of btDiscreteDynamicsWorld running so fast!

Why is that? And is there some diff of the two stepSimulation?

I want to use urdf in c with b3RobotSimulatorClientAPI, but the stepSimulation of it is too slowly (>200times).

Macos 10.14.3

[erwincoumans]

What timestep and number of solver iterations did you use? Default in robotics is 240 Hz and 50 iterations. How did you benchmark exactly?

[Evi5]

changed the same program for diff with stepSimulation (b3RobotSimulatorClientAPI_NoDirect or btDiscreteDynamicsWorld)

debug results shows that slowly problem is caused by stepSimulation

program A ` gContactProcessedCallback = myContactProcessedCallback;

    m_collisionConfiguration = new btDefaultCollisionConfiguration();

    m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);

    btVector3 worldAabbMin(-10000, -10000, -10000);
    btVector3 worldAabbMax(10000, 10000, 10000);
    m_broadphase = new btAxisSweep3(worldAabbMin, worldAabbMax);

    m_solver = new btSequentialImpulseConstraintSolver;

    m_dynamicsWorld = new btDiscreteDynamicsWorld(m_dispatcher, m_broadphase, m_solver, m_collisionConfiguration);

    btScalar timeStep = 0.01;
    m_dynamicsWorld->stepSimulation(timeStep, 50, timeStep);

`

program B `

    b3RobotSimulatorClientAPI m_robotSim;

    m_robotSim.stepSimulation();

`

total running time: program A 0.837053 seconds program B 89.4724 seconds

the program is try to train 10 quadrupedRobots to walk in 1 time,

I am not sure the solver iterations, maybe it's the key?

[erwincoumans]

Timestep should be 1./240. to be equal. m_dynamicsWorld->getSolverInfo().m_numSolverIterations=50 What is inside each world? b3RobotSimulatorClientAPI creates btMultiBody by default.

Please don't use Baido links, just attach zipped source code.

[Evi5]

thank you !

I think it's not the problem of stepSimulation according to your answer.

Just check codes and add "m_robotSim->removeBody(this->m_minitaurUid);" in "virtual ~TableRobot ()" fix a bug that add a new robot should delete the old one.

Program B has been speed up to 11.1226 seconds, because we load a robot from urdf, the time is seems to be ok.

Comment out the stepSimulation in program B time less than 1 second, that I just think the stepSimulation of m_robotSim is slowly. that so stupid~.~

there is no m_numSolverIterations but m_numIterations I changed program A to

m_dynamicsWorld->getSolverInfo().m_numIterations=50;
btScalar timeStep = 1./240.;
m_dynamicsWorld->stepSimulation(timeStep, 50, timeStep);

total time up to 2.05036 seconds

download link has been delete. codes follow for the one who want to learning

hw_6_code_RobotSimulatorClientAPI_11.1226 seconds.zip

hw_6_code_OpenGL_2.05036 seconds.zip