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In the Rigid-body settings, there are two options, Active and Passive.

My question is, What exactly does the Passive setting do? how is it different than Animated Active?
(I know what Active and Passive are, just not what the difference between Active Animated and Passive Animated is)

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Thanks

gandalf3
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2 Answers2

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They act the same but have a very different purpose. Passive Animated just updates the objects during the simulation. Active Animated is used to key-framed the initial momentum

animate the location or rotation of an Active physics object as well as the Animated checkbox. When the curve on the Animated property switches to disabled, the physics engine takes over using the object's last known location, rotation and velocities.

Quoted from: http://wiki.blender.org/index.php/User:Sergof/GSoC2012/Documentation#Animation

gandalf3
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Aldrik
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Active objects are the core part of the physics simulation, with dynamic movement, gravity, etc. By checking Active, you are essentially telling the Physics simulator that those objects should experience forces, and it has to figure out where they go over the course of the simulation.

Passive objects, on the other hand, are fixed in place--are static. For the purposes of the simulation, they essentially act as rigid-bodied, static, collision objects. The Animated option allows you to control its motion with keyframes, but it still does not experience the forces modeled on Active objects.

For example, if you're making a simulation of a ball falling onto a table, the ball would be an Active object, since it is affected by gravity, whereas the table would be Passive, since it is fixed in place.

Gwen
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  • Why not only have Active, with an option for animated? what is different about passive from an animated active? – gandalf3 Jun 30 '13 at 21:39
  • @gandalf3 Passive animated and Active animated, to the best of my knowledge, do the same things, but the internal calculations Blender uses are different. – Gwen Jul 01 '13 at 15:53
  • They act the same but have a very different purpose. Passive Animated just updates the objects during the simulation. Active Animated is used to key-framed the initial momentum (see quote in my answer). – Aldrik Jul 01 '13 at 16:35
  • @Aldrik I get it.. thanks. accepting answer. – gandalf3 Jul 01 '13 at 16:39
  • This answer is better than the accepted one. – ComputerScientist Apr 29 '20 at 21:17