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physics problem
Open, Confirmed, MediumPublic

Description

System Information
Operating system: Windows 10 Pro 64-bit
Graphics card: 4095MB NVIDIA GeForce GTX 1080 (NVIDIA)

Blender Version
blender-2.80rc1-windows64
Worked: (optional)

Short description of error
Simple physics object is trapped in previous (deleted) animated properties.
Exact steps for others to reproduce the error

I have included a blend file which consist of just a cube with physics properties added.
It is supposed to fall but it moves to the origin and stays there.
The file is a working file from which everything has been deleted and a cube added.
Run the animation and the cube will behave oddly.
If the cube is deleted and a different mesh added, say a sphere and moved and basic physics assigned. It will do the same.
This is likely to be a problem with my file from which everything has been deleted??

Details

Type
Bug

Event Timeline

This seems to have been caused by left over animation bakes after objects have been deleted from the scene.
Resetting the animation time has solved the problem.
Don't know why the new object was affected but resetting simulation end time fixes the issue.

Sebastian Parborg (zeddb) lowered the priority of this task from Needs Triage by Developer to Confirmed, Medium.

@Sergey Sharybin (sergey) the simulation starts working if I just simply have the "Step Per Second" input box refresh (click and press enter).
So I'm guessing that it triggers some re-evaluation of data.

@Sebastian Parborg (zeddb), the workaround you've provided makes no difference for me. I think the proper way is to enable "Animated" option in rigid body world settings of the cube.

I am not really into diffing into exact design decision in this area since this is not a regression compared to 2.79. Maybe @Sergej Reich (sergof) will give some clues here.

Yes, this is not a regression, but a quirk of how rigid body cache works.
As noted above you only need to "Delete Bake".
One thing we could do is flag cache as outdated after the the user has pressed "Delete Bake".
The way it is now, you still have to make a change to the simulation before that happens (like modifying or moving objects).