Different kind of object transformations and their effects

Questions
1

Hi everyone. Im quite new to threeJS and im having abit of problem understanding how each kind of transformation works. In the scene, the red cylinder represents the center of the scene.

CASE 1 – setPosition() is being ignored

cylinder2.translateX(-10);
cylinder2.matrix.setPosition(0,10,0);

image

CASE 2 – translateX() is being ignored

 cylinder2.matrixAutoUpdate = false;
 cylinder2.translateX(-10);
 cylinder2.matrix.setPosition(0, 10, 0);

image

CASE 3 – TranslateX is being ignored if matrixAutoUpdate(true) is not set afterwards. (and in this case the setPosition is being ignored)

cylinder2.matrixAutoUpdate = false;
cylinder2.translateX(-10);
cylinder2.matrix.setPosition(0, 10, 0);
cylinder2.matrixAutoUpdate = true;

image

Can somebody help me understand the 3 cases?

Thank you.