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Physics should recognize and handle small scenes / objects
Closed, InvalidPublic


WIN7 / NVidia

Blender Version

More a suggestion than a bug...

Physics with rigid bodies behave strange when using small objects.
Objects penetrate floor surfaces and jump around in unexpected manner.

Struggled around for several hours with rigid body collisions at my scene built up in precise, original sizes regarding to object dimensions.
Imagine a billard table in metrics centimeters.

Could not get physics to work correctly.

Tried values for friction and bounciness, values for steps per second in the rigid body world, for hours, and thought, well, blender physics is not yet usable.

Per coincidence I discovered a tutorial from Andrew Price, where he mentioned to scale the physics objects very large. OK, I tried to scale the objects per 50, that worked much better.

A simple solution, and helped to make the physics going well. Too bad that I couldnt find this solution on google in time.
But anyways, I would prefer to use the precise and original sizes of objects, not a wine glas that has a giant height of 4 meters.

1st approach (but not a real solution):
The Physics engine should notice the user, that his objects are too small in size for a good physics animation and should be scaled by factor 50 or so.

2nd approach, very easy to implement, but even not a real solution:
In the blender documention (which is not soooo good at this moment, at least regarding physics), state that if one has unexpected behaviours, --> "SCALE YOUR ENTIRE SCENE UP!!!!"
That little missing statement in the docu would have saved me hours...

3rd (best) approach:
The physics engine might scale the scene only for internal physic calculations by itself without having the user to do that. So that one could keep his 5 cm Balls on a billard plane what they really are.

By the way and speaking about Docu:
We would like to have a better description about values like Friction and Bounciness for example. How they interact between objects and the Rigid Body World.
Main topic here is the interaction between colliding objects with different values for friction and bounciness. Examples with different values per object in the docu would be great...

This also belongs to the tool tips in blender where you can change the values.
A little bit more description!

So keep your great work going on!!!!


Event Timeline

Bastien Montagne (mont29) changed the task status from Unknown Status to Invalid.Dec 9 2016, 9:59 AM
Bastien Montagne (mont29) claimed this task.

Thanks for the suggestion, but we do not accept feature requests or suggestions on this tracker (use forums or bf-funboard ML for that).