# Geometry rotation and traslation

Hi,
I’m trying to rotate a cylinder. Reading some answers I understood that when rotating around the origin the best thing is to define the cylinder at the origin, rotate it and then translate it. I just don’t understand how to do it? I’ll give you an example of how I tried to do it.

Rotation.inp (1.0 KB)

Hi Andrea,

Please have a look at this lecture:

Cheers,
David

Thank you.
If I translate and rotate a volume, do I also have to carry out the same transformations for the userbin score or does this automatically give me the result for the rotated and translated volume?

Dear Andrea,

The USRBIN scorings are independent of the geometry (except the Region based ones).

If you want to match the axes of the scoring with the rotated body (e.g. a cylindrical scoring on a cylinder with non-z axis), then you need to rotate the scoring.
However, if the scoring doesn’t need to match exactly the geometry (like a fluence map), then it is not necessary.

Cheers,
David

So if I have rotated, for example, a cube and I want to calculate the dose using the region mode, I must also rotate the USRBIN score, right?

Dear Andrea,

No. The region-based USRBIN scoring doesn’t have a coordinate system, it will aways score in the specific regions, whether they are rotated or not.

Cheers,
David

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