How does object.rotation work?

Hi,

I’m trying understand how work rotations property on objects. I need to do a lot of rotations, but when i do the first rotations i dont understand the behavior of the next rotations.

this.de2ra = function(degree)   { return degree*(Math.PI/180); }

This work ok alone:

this.cube.rotation.y = this.de2ra(90);

and this too:

this.cube.rotation.x = this.de2ra(45);

but if i do this:

this.cube.rotation.y = this.de2ra(90);
this.cube.rotation.x = this.de2ra(45);

if the exactly the same of this:

this.cube.rotation.y = this.de2ra(90);
this.cube.rotation.z = this.de2ra(45);

Anyone can explain me why work like that? Ty all, and sorry for my english.

[WestLangley]

Rotations occur in the order specified by object.eulerOrder, not in the order you specify them.

The default Euler order is ‘XYZ’, so rotations are by default performed in the order X-first, then Y, then Z.

Rotations are performed with respect to the oject’s internal coordinate system – not the world coordinate system. So, for example, after the X-rotation occurs, the object’s Y- and Z- axes will generally no longer be aligned with the world axes.

[Pennswood]

So if I want to rotate with regards to world coordinate, must I do some really hard math regarding to Quaternion and stuff, or is there some command to just rotate on world coordinate, cause that is some pain in the neck.