Does scale matter, as long as I keep it the same?

Unity Engine
1

Hi all,
I’m going to be using Cheetah for creating my assets.
I’ve used other engines in the past and had a lot of trouble with scale.

As far as Unity is concerned, do I need to worry about exporting at a certain scale as long as I am consistent with that scale?

For instance if I just decide that one Cheetah unit is equal to a foot (just an example), as long as I use that same ratio for all my assets… will I be OK?

Thanks.

2

The scale you chose does not matter except for physics. The default gravity is set assuming 1 unit == 1 meter, so make sure to change that to fit.

3

The scale matters a lot in the Scene View, as moving around in the scene and zooming in on objects is very scale dependent.

They scale matters a lot in the terrain editor, because some values you cannot adjust, like the overall density of grass. So if you want to make a really big terrain with really big grass, you can’t get the grass sparse enough for sane performance.

The scale matters a lot because float precision is limited, and its precision is centered around zero.

I don’t know how to recommend an exact scale, but I would err on the side of small.

I just think the notion that Unity is scaleless is completely incorrect, but it’d be nice if it were more so.

Cheers,
-Jon

4

unless you like “cool zfight issues” especially with transparent and semi transparent objects try to keep your world within the ± 3000 3d unit range, potentially even less.

5

I was wondering about this as well. Should we build to “real world” scale when building prefabs in our chosen 3d app?

For example assuming a typical room has a height of 2.4 meters (8ft) should I build in that scale in my 3D app?

Is unity based off real world scaling? I was actually trying to find info on this in the documention and couldn’t find it, so I happened across this topic in my searches.

6

Ok cool… and I remember reading somewhere that one Cheetah3d unit = 1 Unity unit… so I just need to convert all my measurements from feet (since that’s what I’m used to) to meters and I should be good to go.

Unless of course I’m missing something. :wink:

Thanks a lot all!

7

There is no real world scaling within a computer, not even the graphics API have such a thing. Its all fictive units.
Don’t know which 3D modelling creator started off with the units but outside the application their meaning is undefined and is up to the target app to be interpreted as long as it does not fully support the original mesh format and “unit system” of it.

8

I keep meter in max and build all items in “real” size.
Then I change the import settings in Unity to 1. Is their accually any reason to do that?
:?:

9

Perhaps one factor in getting the scale right is whether you’re going to use the FPS prefab. Things I’ve made in Cheetah, and terrains I’ve made in Unity, all seem to be at the right size for use with the FPS camera, if I leave the default scales as they are.

If you’re doing your own camera, then you can position it and move it with your own scale in mind, but as someone said the physics may not work as expected if the scale is very strange.