Issues with 3dsmax and Unity3d scale

Question

I changed the units in Blender so they are identical to Unity 3d. If I make a 1m^3 box in Blender, it will import into unity as exactly the same size as the standard cube.

With 3ds max, I changed the unit setup to metric and made sure it was centimeters in the system unit setup tab. However, when I import an obj file made in Blender and used in Unity, it is absolutely tiny. I have to convert the model to meters on import and then, when exporting, I have to set the model scale to .01 otherwise it is enormous in the unity scene.

I've tried changing the max units to meters and nothing changed.

How do you change the max unit/grid setup so one grid unit is 1m^2 and exactly equivalent to unity's grid?

Answer 1

Obj files don't save what measuring unit you are using, only coordinates. If you used meters and made a 1m³ cube, it would save something like:

(0,0,0) (1,0,0) (0,1,0) (0,0,1) (1,1,0) (0,1,1) (1,0,1) (1,1,1)

There would be no mention of meters or centimeters in that file. If you were to open that file in a program that uses centimeters, it would see it as a 1cm³ cube instead of a 1m³ cube, and vice versa.

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I'm not proficient with 3ds Max, but from what I've seen, there are a few possible reasons why yours works the way it does:

• First problem could be scaling. 3ds Max could be scaling your models to 0.01, you have to set that to 1 and I'm not sure how you do this, but this is most likely not the problem you have (see this link).

• Second problem could be that you are using the wrong units as your export. You said you were using centimeters, where you need to use meters (see this link). You can change this from the interface menu (see this link).

Answer 2

For importing 3D max objects correctly in Unity (by same Scale and Pivot) you need to do the following:

1- Scale issue

1-1: In 3D max go to Customize -> Units Setup

1-2: Click on System Unit Setup

1-3: Select 1 Unit = 1 Meter and select ok

1-4: Also in Units Setup select Meters for Metric in Display Unit Scale

2- Pivot/ Coordinate issue

2-1: In 3D Max Select any object and go to Hierarchy and select Pivot and Affect Pivot Only

2-2: Then select the Rotating tool from the toolbar and add 90 in x Axis.

2-3: unclick "Affect Pivot Only" in Hierarchy

----Done----

You can open 3D max files in Unity totally fine now :)