Incorrect flow

[egedib]

Hi!
It seems if two objects are nested I can see the further object's flow and I can see the objects' flow when there is a wall between the camera and the objects.

Reproduction:

1. Open the project in Unity, then open scene: Room 02.
2. From the Mover object, I deleted all Waypoint except Mover Waypoint (0)
3. Import a Blend model. It's an animated cube. cube_blend.zip
4. Place the cube two times to the scene, size set to 0.25. Both times modify the Light object's intensity to 1 (instead of the imported 1000). Create Animation Controller, added the animation, slowed it down to 0.25x and set it to loop, then connect it to the Cubes.
5. Open the Python project, modified with imsave methods to save flow and main image and I set the resolution to 960x540, the imshow functions are deleted.

I tried the following options separately and together:

• Added Rigidbody
• Added Mesh Renderer
• Added Mesh Collider
• Change the cubes' place in the hierarchy
• Disabled the lights
• Used separate Animation Controller

Example 1:
Both cubes are moving, but if you look at the flow, the flow of the rear cube is seen fully. This is not desirable behaviour, because the front cube's flow should cover the rear one.

Example 2:
The boxes are now moving sideways, I can see fully the flow of the rear cube.

Example 3:
I can see the flow through the wall.

Example 4:
Here the objects' size (in the flow) looks wrong.

I can send you the project files if those are needed.

[enricomeloni]

Hello @egedib, thank you very much for the well-detailed issue. We will be trying to reproduce the bug and fix it.

If you have any other comment or suggestion don't hesitate to write us an email or issue!

[InsaneMonster]

I reproduced this. The best workaround currently is to not use an Animator but use a script moving the objects with physics (one is provided by default for rotation, for example). In the meanwhile, I will look into it to understand the deeper causes of this and I will try to see if I can find a way to make it work also with Animators.

[egedib]

Thank you for the fast reply and for the workaround!

[egedib]

Unfortunately, if I move an object with the Poltergeist script, there is a problem too.
I used Chair 01 and the following properties for the Poltergeist script:

• Action Waits Time min and max: 1
• Force Intensity min and max: 60.4
• Torque Intensity min and max: 64

[enricomeloni]

Hello @egedib, thanks for the further example! We are looking on it!

[InsaneMonster]

@egedib Just wanted to update on this issue. By futher investigation I am not able to consistently reproduce the bug. I noticed the bug exists when objects are further away and it disappear up close. Also, it doesn't appear with every object. We will continue investigating our code, but there could be a possibility this issue comes from the way Unity computes motion vectors.