Units

I realized many people do not understand how Units work, in 3ds Max, but it is easy to use and it makes your life easy.

First, you need to understand different between system unit and display unit. (To see this setup go to Customize – Units Setup)

First I’ll talk about “Display Unit”.

This is how to display your model in a scene. Or I would say how you want to create your model using inches or meters. Display Unit doesn’t affect model size. Just affect how to display your measurement.

For example:

To create 1”x1”x1” cubic using the inches display unit (Don’t worry about system unit now.) Then change display units to meters. Nothing changes but the model size is now .025m x .025m x .025m because 1” = .025m

Next is “System Unit”.

This is important to know for when you are going to import and export your scene or objects because this part controls the size.

For example:

Create a 1”x1”x1’’ cubic using inches system unit. Then changes the system units to meters. The model size is now 3'3 11/32" x 3'3 11/32" x 3'3 11/32". If you change Display Unit to meter, the model size is shown 1mx1mx1m because 1 Generic Units = 1 inch = 1 meter. (Generic Units is placed bottom of Display Unit Scale (1))

This is the basic idea for how units work in 3ds max.

Next important thing is “Respect System Units in Files” option (2).

When you open System Unit Setup, there is a check box called “Respect System Units in Files”. If you turn on this option, “File Load: Units Mismatch” pops up when you open a file with different system units.

For example:

Your current scene system unit is meters then you open a different scene that system unit is inches, “File Load: Units Mismatch” will pop up in your view port and there are 2 options you can choose (3).

1-Rescale the File Objects to the System Unit Scale?

2-Adopt File’s Unit Scale?

First option changes the scene system unit from inches to meters in this case. However, the model size isn’t affected. If the model size changed, please check absolute scale. It may not 100.

Second option does; Nothing changes. The scene system scale is same as before.