Question about Blender Units (BU)

I’m a little confused about something. I wanted to make some models for a game. The game uses Valve’s Source engine, in which 1 unit is equivalent to 1 inch. I’m not quite sure how this works in Blender. If I want to make a model that’s, say, exactly 50 “inches” in diameter… how do I know if I’m making it the right size? I see no indication of size for anything.

And also, is there a way to measure the length of things? Or scale to a specific size?

Is the default cube 1BU x 1BU x 1BU? This is kind of confusing.


the BU can be anythng you want it’s adimensionnal

so usually you can make it as 1 BU = 1 meter or i foot

now i you add a cube press N-Key a panel will appear and you

can check out all the dimensions for the cube

now when you export you must have some sort of scale factor when you import in the other soft i guess


Thank you, that’s helpful. I never knew about the N-Key.

It also completely depends on how the exporter for a certain engine works. Most engines I have worked have with have conveniently gone with 1 Blender Unit = 1 meter in game, but sometimes it is not that simple. This could be especially problematic if there is not an exporter for your particular engine and you have to go through a pipeline where you export to a common standard (like obj) import to another program (like Millkshape) and then export from there.

Here is a quick list I made a while back for exporting to the Torque Game Engine, which may have some similar qualities:

1 blender unit =
1 torque unit =
1 meter =
1 meter in game world =
32 QuArK Units =
1 3DSMax Unit =
1 Maya Meter =
80 MilkShape units

And, a few related items of interest.

  • The Orc in TGE demo is approx 2.4 units tall.

  • A human, then, would be a little less than 2 blender units.

  • The default box in Blender is 2 units tall.

The best way to figure out the units for this engine is to make a 1 x 1 x 1 BU cube, export it, and compare it to something that you know the exact dimensions of in the engine. There is often some sort of obvious and precise correlation.