You must be in the Edit objects tab.
- Select object: RMB
- Get out of selection mode: H
- Select multiple objects: In the list of placed objects (the first list), click on an object while holding CTRL. This also works when selecting directly on the map.
- Select a group of objects: Click on the first object of the group, then click on the last one while holding SHIFT.
TIP: Selecting an object can be really hard sometimes, depending on the geometry of the prop, e.g. you placed 50 fishes somewhere and you want to rotate only ONE. If you encounter this situation, find or place a similar object and select it. You will notice that the name of your object will be highlighted on the list in the panel. Since props are sorted alphabetically, you can look for your fish in the list of 50 fishes. This option can take a bit of time, but quite often, it will be your only option.
- Move down/up: Hold T.
TIP: You can also copy/paste the vertical position of an object with Pos Z.
- Move on the horizontal axis: Hold G.
- Rotate the object: X (central axis), Z (red axis) or Y (green axis).
TIP: This will also work on a group of objects. For example, you could rotate a whole house without destroying the structure of the house.
- Copy the axis position of an object: SHIFT + R
- Paste the axis position of an object: R
TIP: Don't waste time looking at the axis, just save the position, press X, Z or Y randomly and switch back to the original position with R if needed.
Warning: Doing this on a group of objects would only change the position of each object individually.
- Modifying the scale of an object is one of the most useful features. Don't use B, as that's not an accurate method. Fill up the "scale" blocks directly, and don't hesitate to copy/paste between different objects. Also note that you can reverse an object by pressing the "Invert" button, but this method can cause collision problems (get-through objects).