Animation freeze when interacting with mouse

[mwestphal]

Steps to reproduce

• ./bin/f3d BoxAnimated.gltf
• zoom out
• press space
• move the scene while animation is running
• animation is not smooth

[mwestphal]

@Meakk I see this on Linux too. It seems to be a 2.0.0 regression, works perfect with 1.3.0

[exbluesbreaker]

Hello, where to find this file to reproduce?

[mwestphal]

Its BoxAnimated.gltf from testing/data.

[exbluesbreaker]

I am working on this issue. So far it seems it is not problem of rendering being blocked somehow, but of animated object geometry not being updated while mouse movement.

I forced calling this->RenderUI(that) in vtkF3DImguiObserver::MouseMove which commened not being necessary and freezing is the same. So it tries to render quite actively but object "doesn't move"

[exbluesbreaker]

It seems something is wrong with animationManager::Tick timings when mouse is being moved and maybe it is related to std::chrono::steady_clock usage.

I checked internal duration counter in animationManager::Tick using std::chrono::steady_clock and it actually shows always perfect duration, despite me seeing freezes of animation and even delay of debug output of this value. So I used std::chrono::high_resolution_clock to measure time between Tick calls and this clock is able to detect big delays properly.

Anyway, I will keep investigation.

[exbluesbreaker]

Some update, though without direct impact yet. I investigating behvior over the weekend. It was mainly tracking animation/interaction how is it done in VTK in general and in particular processing.

Essentially event processing takes too long which delays firering timers which would cause animation updates. So with rough skeleton event processing is taking longer:

...
void vtkXRenderWindowInteractor::ProcessEvents()
{
  ...
  for (Display* dpy : dpys)
  {
    //Event processing
  }

  ...
  for (auto rwi : vtkXRenderWindowInteractorInternals::Instances)
  {
    if (!rwi->Done)
    {
      rwi->FireTimers();//Fire timers
    }
    ...
}

In the end I found out that "default" interactor implementation is taking longer times for mouse move, but I didn't figure out details yet. F3D related mouse move processing is registered as observer and is done very fast but there are also default interactor behavior involved.
So far I went to void vtkInteractorStyleTrackballCamera::OnMouseMove() taking long times but didn't proceed yet further (didn't have time).

[exbluesbreaker]

It was in general beneficial for me to learn better how things work with VTK