The rotate modifier will rotate the children of the modifier. It will rotate all the children around the Z-Axis at the origin.
Start by adding a cube.
cube()
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render the cube ( press f5 )
add the rotate transformation and render the model ( press f5 )
rotate(10) cube();
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The cube has rotated in the clockwise direction by 10 degrees.
If you need to rotate the cube about its center, first center the cube then rotate.
rotate(10) cube( center = true );
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You can rotate around any axis by providing a vector. Add
rotate([30,0,0]) cube();
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ok, but how do I rotate around an axis of the cube, if the cube is neither center=true nor positioned along an axis, but somewhere in space, such as rotating translate ([12,24,36]) cube ([5,5,5]) for 35 degrees around an axis parallel to x at the distance 12 ?