The meaning whose scene unit is 20cm

[flat]

example scene of ship.max.
https://docs.chaosgroup.com/display/...Example+Scenes

Although the scene unit is set to 20cm as for this scene, what is this meaning?

How was 20cm decided on?

[georgi.zhekov]

It's chosen this way so the size of the ship in the scene corresponds to a real world scale ship.

[hammerbchen]

My best guess is in the beginning, everything is according to real world scale, and the unit is 1:1.

But after the first sim, sometimes you have to adjust your system unit a bit to get the desired effect. This is why PhoenixFD 3 introduce "scene scale" in the rollout.

[chriserskine]

I've just started using phoenix and I've been wondering about this as well.

I'm doing arch viz and I have all my scenes set up as 1 unit = 1 meter.

Can I just leave it at that, and then use the phoenix 3 scene scale?

[hammerbchen]

my suggestions would be:
1. always make sure your geometry is in right scale
2. make system unit 1:1
3. after the first simulation, play around the "scene scale" in the PHX3 rollout. Try to make it large or smaller and compare the results. PhoenixFD is highly sensitive to its grid resolution, so you might also need to fine-tune it in order to compensate the effect.

[flat]

Thank you for the advice.

[Ivaylo Katev]

i suppose it just remained from a previous scene that was simulated before this one.
the scene/UI units are not important at all (you can use inches if you prefer) , the plausibility of the size and the speed of the object is the important one.

[chriserskine]

thanks,

that's good to know.