# How should I apply inertia for a floating object?

Hello!

I am looking at the XML guide which states:

And I am confused about the wording marked with yellow. Lets take a simple example:

We have a cube placed some distance x and z away from the global origo. My understanding is then that inertia for the cube should be calculated w.r.t. the coordinate system locally at the cube **and it has the same orientation as the global coordinate system.**

This means that if the cube was tilted like this:

Then I would still calculate the inertia **locally at the center of mass, but I would have to make sure that the orientation of the axes, matches the global coordinate system**

Is my understanding correct?

Kind regards

## Comments

Yes, you can also make some tests with a cube or object you know the theoretical inertia first so that you can see the results to understand how to use it

Regards

Thank you very much for confirming it Alex!

And you are indeed right, if I made the discretization fine enough and allowed it to automatically calculate inertia, then it should have been clear to me that way too - thanks for highlighting that approach!

Kind regards