From time to time one can hear the term “local space”. What does it actually mean? If i have rotated an cube, is it some way possible to jump to the “cubes local space”, to continue working without worrieing about the rotation?
Hitting z,x or y on your keyboard ‘twice’ will translate, scale or rotate the object or its parts (verts etc) within its local axis.
It has to do with absolute and relative positioning.
Blender itself is in “World Space”, for instance, Z-Axis is up.
If you rotate around the World Z-Axis this should be clear.
Also every Object has its Local Space. Let´s say you got a cube.
If you create the cube, the cubes Z-Axis shows upward like the World Z-Axis.
If you enter editmode and rotate the cube, and enter Object mode again, the Local Z-Axis still matches the Worlds Z-Axis.
This shows, eventhought the cube is rotated in Editmode, the Objects Local Z-Axis hasn´t changed.
If you rotate the cube in object mode, the local axis of the object rotate as well, therefore the Local Z-Axis does not match the World Z-Axis anymore.
Alt+R always resets those rotations unless you apply the rotation (CRTL+A)
Further there is a global/local coordinate system within edit mode.
If you enter editmode and rotate your cube and its aslope then in the room and you want to rotate it along its own Z axis you would be in a dead end without local space.
Select one of the faces of the aslope cube and press shift+ctrl+c and add. Now you defined a new local coordinate system fitting this face. If you now press A to select all faces and press R (rotate) and Z (world/global z-axis) you will see the faces roatate around the worlds Z axis.
If you press R (rotate) and Z twice (local z-axis) you will see the cube now rotates around the local Z axis defined earlier with the single face.
It´s best to try it and you´ll quickly figure out my crypric description 