Physics world seems outer space

[mreuvers]

Hi there,

We've been working with Bullet on one of our projects and it somehow it seems as if the physics is 'slow-ish'. It's almost as if the objects have a low gravity. We run our game at 60 fps and the stepsimulation is also running at 60 fps. The gravity is (0, -10, 0). And the mass is 1, not that that should matter in an airfrictionless environment. All the right settings if you ask me, but somehow the whole simulation seems to be in slowmotion.

The same thing happens in the demos that are provided in the package. If you startup BasicDemo for instance, you can notice this slow motion effect. If I were to pull a cube out of that stack in real life, things would definitely go faster.

Is it just my imagination, or is there perhaps some missing setting that I forgot to set?

Thanks!


Martijn

[Erwin Coumans]

Note that the objects in most demos are huge, the boxes in BasicDemo are 2 meter. This can make it looks 'slow'.

What is the scale of your objects?
Hope this helps,
Erwin

[Punhey]

I've noticed that the perceived "fastness" of the simulation has everything to do with the ratio of the size of your objects and the value you set for gravity. If you must stick with objects of the size you're using, then raise gravity to make it seem "faster". Though I think for stability's sake, it is better to scale your objects while keeping gravity at a reasonable value, like 10.0. I say that because I've noticed that if you raise gravity substantially, you'll start noticing a sort of jitter in your objects as they fight to penetrate whatever's below them, even when they appear to be at rest.

I hope that helps.