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UE4 Units

Good day, I hope I am posting in the right section. I am boxing out my level for my proof of concept, and I am familiar that Epic has always used their own unit measurement system. I am aware that 96 uu was the character height in UDK and UE3. Is this still valid for UE4? or are the values of uu different? I am wanting to also make sure my unit size is set up properly in my 3DS Max as I would need to make sure that all my model props and stand-ins are proportionate to one another.

I am also wondering if anybody has any advice on creating a volumetric light in UE4. I am using it for the characters flashlight, and its a major part of my concept and design so I wanted to nip that in the bud pretty early on in my development. I am coming from Unity, which is a different kind of beast in its own right, so Unreal in a whole is new to me. I hope im posting in the correct section, and if not then I apologize. good day and happy developing

Unit scaling has changed. Now it’s really simple: 1UU == 1cm.
Also, if you don’t enable some editor option, grid isn’t based on 2^X anymore.
Instead it uses ‘normal’ grid steps like 1, 2, 5, 10, 25, 50, 100…

You can go under the **World Settings **pane and expand the World Settings Tab, here you can change the World Units to Meters conversion ratio.

I’m a bit confused, what does World Units to Meters impact in the engine and the game?

I changed the World to Meters to 1 so 1uu=1m but even after that the measures remain the same… (I went on my viewport and clicked Alt+J to see Top view and then took measures with the third button of the mouse and got 3000. Then restored the World to Meter back to 100 so 1uu=0.01m and did the measures again and got 3000 again… It is strange 3000uu cannot remain the same after telling to UE4 that now those are 3000 meters and not 3000 cm anymore!!! YOU SHOULD FIX THIS!!!

This is for VR, and not the scaling within the game.

It would be useful to have a World Setting that would change the fundamental unit of measurement. I understand that the display units can be set, which makes things straightforward for people using the Editor. It would be nice to have an equivalent setting for the coding side, so dimensions in code can also be specified in a natural coordinate system for the specific game (such as meters, or miles).

Well a unit is not really a form of measurement but a means to establish a scale that is true in all 3d applications and it’s use could only be applied as to the relative scale of an object until you tell your 3d app what a unit represents as a world measurement.

In UDK the only form of measurement was the unit that one would have to decided the “relative” scale of the project and 96 units as the relative character scale does not translate into anything useful as to a real world measurement.

In early 2000 more apps started switching from base units to real world scaling by default and for various reasons so that objects could be build based on world scale and not relative scaling as to objects scaled to one another. In the case of Unreal 4 the world unit measurement is 1 Unreal Unit (as to relative scale) = 1 centimeter (as to real world scale).

The benefit of referencing true world space is anything you built in any 3d application will be true in scale as to it’s real world counter part so if you make use of a flashlights real world measurement in a 3d app set to 1unit = 1cm then the scale is true to world scaling and not relative to other objects.

To set this up in 3ds Max to match UE4

Customize > Units Setup > System Unit Setup > System Unit Scale

Set 1 Unit = 1 in Centimeters

3ds Max is now set up relative in scale to Unreal 4 and all things built will be true to real world counterparts.

After that you can set up “any” display unit scale as the base unit scaling will “always” be 1unit = 1 cm

I would not recommend changing the world scaling in UE4 as a preference