Can you share with us the relevant parts of your "simulation loop"?
For example (I'm using Chrono::Vehicle mostly) a lot of the vehicle
related demos have a simulation loop that goes something like this:
// Simulation loop vehicle.EnableRealtime(true);
while (vis->Run()) {
// Render scene vis->BeginScene();
vis->Render();
vis->EndScene();
// Get driver inputs DriverInputs driver_inputs =driver->GetInputs();
// Update modules (process inputs from other modules) double time
=vehicle.GetSystem()->GetChTime();
driver->Synchronize(time);
vehicle.Synchronize(time,driver_inputs,terrain);
if (add_trailer)
trailer->Synchronize(time,driver_inputs,terrain);
terrain.Synchronize(time);
vis->Synchronize(time,driver_inputs);
// Advance simulation for one timestep for all modules
driver->Advance(step_size);
vehicle.Advance(step_size);
if (add_trailer)
trailer->Advance(step_size);
terrain.Advance(step_size);
vis->Advance(step_size);
}
(taken from demo_VEH_WheeledJSON.cpp)
So you can see it has a flag to determine if it should pause at the end
of each step to stay in realtime (assuming it finished early). It could
be you're missing that flag. It could also be your loop is altogether
slightly different and you need to add some form of sleep at the end of
your loop manually. I have a few loops where I've done this "manually"
as I wanted to have the option not just to sleep at the end of each
step, but, if the simulation ran behind for a short while, to also
"catch up" again. Anyway, such logic is not that hard to write yourself
if you want something that suits your specific scenario.
Greetings, Marcel
On 13-Mar-23 15:14, Alexandre Vinovrski wrote:
I noticed that the simulation runs at different speeds on different
machines. This is normal because it depends on the CPU frequency and
on the operating system scheduling. For example if I run the
simulation on my workstation it will will look slower than if I run it
on my laptop where it looks significantly faster. I need a way of
making sure that my simulation will run at the same speed no matter
the machine.
Le lundi 13 mars 2023 à 13:57:50 UTC+1, [email protected] a écrit :
I think you need to explain more context about what you are trying
to do. From your original question it was not clear to me at all that:
* You are running a simulation on multiple machines.
* You are running that simulation in real-time (as far as I can
interpret from your mails).
* You want to synchronize time on multiple machines?
Greetings, Marcel
On 13-Mar-23 13:40, Alexandre Vinovrski wrote:
To me it seems that the time is managed in a very poor and in an
inadequate way in chrono. I basically need to change it at its
source in order to achieve what I want. I would need a way to
make the simulation run at the same frequency on all machines.
This is normally achieved with deltaTime 'normalization'. I tried
to do that but it doesn't work. I'm using ChFunction which, from
looking at the source code, appears to use a hardcoded step. This
might be the issue why my delta time calculations do not work. At
the moment my simulation runs at different speeds on different
machines.
Le dimanche 12 mars 2023 à 16:03:08 UTC+1, [email protected]
a écrit :
Hi Alexandre,
There are a couple of ways you can get the time:
* system->GetChTime();
* if your simulation runs with a fixed timestep, you can
easily count steps in your physics loop;
I hope that answers your question.
Greetings, Marcel
On 12-Mar-23 15:42, Alexandre Vinovrski wrote:
Hello to all,
We are a team of students working on a project for our
university. We have to implement a genetic algorithm that
allows an individual to walk in a physical engine.
One of the conditions necessary for our algorithm to stop is
the evaluation of the distance travelled based on the delta
time. We have the impression that this essential
functionality for our project is missing in Chrono.
Do you know if this is available, or if there is a
replacement for this method?
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