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Keyframing off Animated property of rigid body on second frame of rigid body simulation
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Description

System Information
OS: Ubuntu 13.10
Linux kernel: 3.11.0-18-generic

Blender Version
Broken: 2.70-b64bdb2-linux-glibc211-x86_64

Short description of error

Normally, keyframing off the Animated property of a rigid body will cause rigid body to maintain its velocity and rotation that it has at the last animated keyframe. However, if the Animated property is keyframed off on the second keyframe of the rigid body simulation, the object will continue the animation from a stand-still, i.e. it loses its initial velocity / rotation.

Exact steps for others to reproduce the error

Create bug:

  1. Open new Blender file
  2. Keyframe location of the default cube
  3. Go to frame 20, move cube along the y-axis by 20 units and keyframe location.
  4. Enable Rigid Body for the cube
  5. Go to frame 10, enable Animated (Physics context -> Rigid Body panel) and keyframe it
  6. Go to frame 11, disable Animated and keyframe it
  7. Go to Scene context -> Rigid Body Cache panel, and set Start to 10 (and say, End to 50)
  8. Go to 3D View and hit ALT A to start animation. Notice that when the cube reaches frame 10, it loses its y-velocity and just falls straight down.

Resolution:

  1. Set the start of Rigid Body Cache to 9.
  2. Update cache by unlinking the RigidBodyWorld group from Rigid Body World panel, then choose it again.
  3. Play animation again, and it's fine.

Although, I have figured out how to get it working, I think this is unexpected behaviour (which took me a long time to figure out).

Steps 1-7 have already been completed in this file:

Details

Type
Bug

Event Timeline

Garrett (Garrett) raised the priority of this task from to Needs Triage by Developer.
Garrett (Garrett) updated the task description. (Show Details)
Garrett (Garrett) added a project: BF Blender.
Garrett (Garrett) set Type to Bug.
Sergej Reich (sergof) lowered the priority of this task from Needs Triage by Developer to Normal.

Hmm, I'll have to think about this. Not quite sure if we can make this work.

Still broken in 2.8. What is the workaround?