Unreal Engine 4 Units

Development World Creation
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1

Hello, I hope I’m in the right section

I’m a newby in UE programming and I’m trying to figure out a few things, one of these is about measurement units.
During my study I’m finding out that there are various measurement units basing on the context, and I’d like to understand more.
For example:

  • In the **Transform section (****Details **panel) which units are used by the scale/location/rotation parameters?
  • When i use, say, the **Get Hit Result Under Cursor by Channel **node (image below), the hit result returns some data (like **location, impact point **and so on), what units do these data use?

cap.PNG

  • Local and World units are different, right?

Thank you and sorry for the (maybe?) dumb questions.

2

Not really. Distance (vector magnitude) is in unreal units, scale is unitless (in this context) - a simple multiplier. Location is a vector, each component XYZ is in unreal units. Normal is a direction vector with length of 1 uu. Rotation is in degrees but radians are used here and there, especially when you deal with physics, angular velocities, for example.

They’re the same. 1uu = 1cm

edit: When you deal with a 2D interface, you’ll be dealing with pixels rather than cm or unreal units.

3

@Everynone thank you for the fast answer,
now everything is more clear.

So if I set the scale of a static mesh for example on

X=1
Y=2
Z=3

1, 2 and 3 are multiplied by what? Is there a constant dimension from where any mesh starts?
I promise, this is the last dumb question :smiley:

4

Scale multiplies the size of the mesh. If your mesh is 100uu in X axis, and you set the X scale to 3, your mesh is now 300uu in X axis.

5

Thank you @Everynone it’s clear now.