Once I get that upgrade to 36-hour days, I will tackle that. – Mychaeel
From Unreal Wiki, The Unreal Engine Documentation Site
One of the interface modes in UnrealEd's toolbox. This mode lets you rotate Brushes or Actors such as meshes. Icon actors which have their Advanced -> bDirectional flag set such as Spotlight can also be rotated like this. Any selection of multiple actors will rotate about the pivot.
Note: do not confuse rotation, something you the mapper does to actors in UnrealEd, with rotators, a type of UnrealScript variable that describes a rotation.
 How it works
You must select one or several elements to rotate. Then, in any type of UnrealEd Viewport, hold down CTRL, click one of the mouse button combinations listed below and drag to rotate the objects. The table below shows:
- The rotation direction
- the axis of rotation this is equivalent to
- the orthogonal viewport in which this rotation is most clearly seen
- the mouse movement to perform this rotation: hold CTRL, click the indicated button and drag in the indicated direction
|Yaw||z-axis||Top view||RMB, drag left or right|
|Pitch||y-axis||Front view||LMB, drag left or right|
|Roll||x-axis||Side view||LMB+RMB, drag up or down|
Brushes and actors are rotated around their pivot point; this can be set outside of the brush.
 Simple rotation
Alternatively, simple rotation can be performed in orthogonal viewports in Camera Movement mode. CTRL+right-drag rotates in a different direction for each view type, as in the list above, eg: yaw in top view.
- The brush shape distorts
This is because the brush has scaling applied. Either:
- transform permanently before rotating, to fix the scaling into the shape of the brush
- do UnrealEd Main Menu -> Brush -> Reset -> Reset Scaling to remove the scaling.
- do UnrealEd Main Menu -> Brush -> Reset -> Reset Rotation to unrotate the brush.
See Brush Transformation for more on this.
- The brush shoots off into the distance
This is due to the position of the pivot. One of the following should work:
- UnrealEd Main Menu -> Brush -> Reset -> Reset Pivot
- ALT + click on the brush's origin
- The brush rotates in the wrong axis
This is due to Gimbal lock, a consequence of using Euler angles to describe rotation in 3D. In other words, sometimes the pitch, yaw, roll system that the Unreal engine uses causes unexpected results. Here's how to see it:
- create a brush, ideally something that's not symmetrical in all dimensions. A cylinder or stairs will do.
- rotate 90 degrees in top view
- switch to side view and rotate. urg!
This is not a bug, it's a mathematical consequence. If you like, it's a bug in the universe. Here's how to work around it:
- once you're done with a particular orientation, remember to reset brush rotation with the Brush Context Menu. That way you're starting from scratch again.
- if you have to rotate in more than one axis, perform the rotations in the same order as Unreal: pitch, yaw, roll: side view, top view, front view. This won't solve all problems, but rotating in two axes in that order should be fine.
 Beginner Tips on Rotation
- Only rotate with the pivot point for the brush in the center of the brush.
- Use the 2d views for rotating where the rotated brush will align with the X, Y or Z axis.
- Edit the brush properties and do precise rotation in the Movement - Rotation - (pitch, roll, yaw) values. This is generally easier to get the exact rotation than rotating in one of the 2d views. Here are some useful values:
- | Value | Degrees |
- |> 8192 |> 45
- |> 16384 |> 90
- |> 24576 |> 135
- |> 32768 |> 180
- Rotate the brush such that its vertices are aligned with the grid points. This makes it significantly easier to align texture in your finished map. See Surface Alignment
- Consider Brush_Clipping to trim down one or more sides of a cube to get the shape you desire. This has the advantage of allowing you to have one or two sides still parallel to X, Y or Z axis. This greatly helps when aligning the brush to the floor and also in aligning texture.