Physic simulation runs twice

[rikard-io]

• Device Model: iPhone 7
• Xcode Version: 9.1
• iOS Version: 11.1
• Pod Version or Repo Commit: 1.4.2

Running with ARKit and rendering a ARSCNView

Issue Details:
Seems like the physic simulation gets run twice, once in the actual sceneView rendering and once in the SCNRenderer when recording. This results in a speedup in any physics-driven motion

Temporary and ugly workaround is to set physic simulation speed to half before recording and restore after recording is finished. (sceneView.scene.physicsWorld.speed = 0.5)

Might be somewhat related to #28

Thanks for a very useful lib!

[Francescu]

To complete @rikardjh's workaround, for particles:

            if recording {
                self.rootNode.particleSystems?.forEach { particle in
                    particle.speedFactor = particle.speedFactor / 2.0
                }
            }
            else {
                self.rootNode.particleSystems?.forEach { particle in
                    particle.speedFactor = particle.speedFactor * 2.0
                }
            }

[okaris]

I am looking for a solution that doesn't require manually manipulating the speed factor. If I can't find in a timeful manner I will add this as a temporary solution.

[kyleweiner]

@okaris Has there been any progress on this issue or is manually manipulating properties for the recording state still the recommended solution?

@Francescu Curious if you’re using this workaround in Arrow. Very fun app by the way!

[okaris]

I don't remember finding a solution for this. I am no longer maintaining this repo. Maybe @halileohalilei can help.

[Francescu]

@kyleweiner thanks for the kind words 😇

The trick is still used in production for the Arrow app 🙈

[kyleweiner]

Looks like it gets the job done for now. Thanks for the info 👍