Units Setup Dialog

Customize menu > Units Setup > Units Setup dialog

The Units Setup dialog establishes the unit display method, giving you the choice between generic units and standard units (feet and inches, or metric). You can also create custom units, which are used whenever you create an object.

The units that you set up are used to measure geometry in your scene. In addition to these units, the software also uses scene units as an internal mechanism. Do not change your scene units unless you have unacceptable viewport behavior.

You can also set the lighting units using this dialog.

Scene vs. Display Units

It is important to note the distance between Scene and Display units. Display units only affect how geometry is displayed in the viewports. Scene units determine the actual scale of geometry. For example, if you import a DXF file (unitless) containing a 1 x 1 x 1 Box, 3ds max may import the box’s dimensions in inches or miles, depending on the Scene unit. This can have a significant impact on your scene.

Procedures

To change units to feet and inches:

In Units Setup, choose US Standard.
For Default Units, choose Feet or Inches.
Select from among the choices on the drop-down list.
- If you want feet, choose how the inches will appear, as fractions or decimal.
- If you choose Fractional Feet or Feet w/ Fractional Inches, choose the fraction on the drop-down list to the right.

To enter fractions in numeric fields:

When you enter fractions in numeric fields, they are converted to the correct units. For example, if units are set to Feet w/ Decimal Inches, and Default Units is set to Feet, type 37/45 and press ENTER for the result 0'9.867", or 37/45'.

To enter a fraction and a units specifier, place the specifier after the divisor. For example, type 17/5', but not 17'/5.

To convert between unit types:

You can convert between unit types by entering any valid unit specifier, along with the number, and then pressing ENTER.
The number is converted to the current unit display type. For example, if units are set to Meters, type 1/2 to get the result 0.5M. However, if you type 1/2' or 6" the result is 0.152M.

Interface

System Unit Setup—Click to display a System Unit Setup dialog and change the scene unit scale.

Warning: You should change these values only if you're working on a scene so huge or so tiny that the software can no longer measure distances accurately using the default unit scale. If you change this value, you make the scale of the objects you create incompatible with objects in scenes created with the default unit scale.

Display Unit Scale group

Click one of the option buttons (Metric, US Standard, Custom, or Generic) to activate its settings.

Metric—Click the list and choose a metric unit: Millimeters, Centimeters, Meters, Kilometers

US Standard—Click the list and choose a US Standard unit. If you choose a fractional unit, the adjoining list activates to let you select the fractional component. The decimal units require no additional specification.

The US Standards are as follows:

Fractional Inches
Decimal Inches
Fractional Feet
Decimal Feet
Feet w/ Fractional Inches
Feet w/ Decimal Inches

For the last two items, you can specify which unit is assumed when you enter a value in a numeric field and press ENTER without including a units specifier, such as ' for feet or " for inches.

For example, if Feet is the default, typing 5 followed by ENTER results in 5 feet. Typing 5" followed by ENTER results in 0'5". If Inches is the default, typing 5 followed by ENTER results in 0'5". Typing 5' followed by ENTER results in 5 feet.

Custom—Fill in the fields to define a custom unit of measurement.

Generic—This is the default option (one inch) and is equal to the scene unit used by the software.

Lighting Units group

The Lighting Units group lets you choose whether light values are displayed in American or International units.