Confused about units of scale used for Nav mesh volume

I understand default unit for transforms in unreal is cm. So that when i setup transforms numbers for actor in the scene 100 means 1 meter. Atleast for scaling that is.

So i open default level in editor and set the floor size scale to 100x 100y 1z
i then drag navmesh volume into the same scene and scale the size to 500x 500y 10z

Dont care about the Z at this point, but on the screen the floor and navmesh visually are round about the same size in terms of x and y, the nav mesh at 500units covers the entire floor sized at 100 units.
I would expect the nav mesh to be 5 times bigger than the floor.

So can a kind person please explain to me what unit is used for the scene and why a box of 500units is same as 100units


First, set both actors to uniform scale. Now adjust the Nav Mesh’s brush size (not scale) to equal that of the floor. The Nav Mesh should now scale relative to the floor size.

Thanks for the reply

1 - I only know about World and relative scale as set from details panel for actors, never heard of “uniform scale” cant seem to find such option in details panel for both actors. Both floor and nav mesh volume are set to relative scale by default.

2 - I have checked the nav mesh actor details panel and cant find anything on brush size

unless my common sense is failing me, id say epic made this very confusing, how can i set same scale for 2 actors in transform and one is 5 times bigger than the other, and the reason is not clearly obvious to see there in details panel. It means those new to this tool like me gona have a hard time relying on common sense application for this supposed epic tool.

thanks for the tip

Sorry, I didn’t explain it well at all. Reset the scale for both objects to 1.0-1.0-1.0, and then adjust the Nav Mesh properties to match this screenshot:

Scaling an object doesn’t set it’s size, it multiplies it’s size. Also I would strongly recommend completing the AI Quick Start Guide.