Bifrost, speed up movement?

[hinobayashi]

Hi everyone,

I'm working with Bifrost, but am having the problem, that the simulation is too slow.

Is there a way to speed up the particle movement?

I've tried scaling my Models up and down, but it didn't seem to have any effect.

It would be nice if you could help me as the deadline is very close.

Best regards!

[agraham · Accepted solution]

I think you want to change the 'scale' of your simulation, right?

If so, then you'll have to change your gravityMult on your container. This is kind of like the 'master control' for defining the scale of your simulation.

The default is 9.8, which is meters/second, squared. This assumes 1 unit = 1 meter, which is pretty big. If you're building a smaller scale scene (say, 1 unit = 1 cm), you'll have to change your gravityMult to 980. Of course, as things move that much faster, you'll have to increase your adaptivity settings to accommodate.

[hinobayashi]

Hi agraham,

Thank you very much for your help!
That was exactly what I was looking for.

Best regards.

[Anonymous]

Hey there, that was a useful info. Thanks. But how is it differ from changing the Transport Time Scale?

[agraham]

This page in the docs is helpful for understanding scene scale:

    Bifröst simulations and scene scale

Transport Time Scale increases/decreases the speed of the particle flow. It's not physically realistic, but can sometimes get you what you need. From the docs:

"Changes the speed of the particle flow. Values greater than 1.0 speed up the flow without introducing any new velocities or accelerations, while values between 0.0 and 1.0 slow it down. The result is not physically correct, but it can be useful if you just want to quickly retime a simulation. Be careful because it may introduce unwanted side-effects, especially at extreme settings."