Possible Duplicate:
Rotating a custom geometry mesh around its center point
JSFiddle of this code is here...
I have a geometry loaded with ObjLoader in to the scene with theese vertices (A Simple double sided mat. triange) (I have manually defined vertices to re-create the sample, not used ObjLoader in the fiddle)
var geom = new THREE.Geometry();
geom.vertices.push(new THREE.Vector3(-4.77353, 2.7, 0.660501));
geom.vertices.push(new THREE.Vector3(-0.521001, 2.7, 0.660501));
geom.vertices.push(new THREE.Vector3(-0.521, 2.7, -2.065922));
In the world its position is (0, 0, 0) but according to its vertices i calculated its center point and now try to rotate this triagle around this centroid.
As you see in the fiddle, when i rotate the object on x asis by giving rotation value, it is rotated on x, y and z axis with 0.1 radians in each render. But i only need it to be rotated on x axis.
Note: Please check the fiddle first, before you answer the question.
Thanks for further helps