Pressing Esc activates/deactivates the Fly mode. In this mode the viewport is navigated by use of
- W: Forward;
- S: Back;
- A: Left;
- D: Right,
- Space: Up;
- F: Down.
Fly speed can be adjusted by moving
- Forward: Faster;
- Backwards: Slower.
In order to understand the viewport navigation that goes hand in hand seamlessly with editing it is important to understand some basics first:
The view of the viewport can be understood as a camera that points into the scene (see image on the right). For purposes of viewport navigation, what appears in the view is defined by two parameters:
- View origin
- The position of the camera in 3D space. View origin is the point where all three axes meet in the right image.
- View focus
- The position of a target point in 3D space. View focus is not illustrated in the image on the right but the view focus is necessarily positioned somwehere on the negative part of the z axis.
Now that this is out of the way let's focus on navigating. Navigating the viewport is nothing but changing the view origin. This can be achieved be either changing the view origin itself which, in some cases, will also change the view focus, or by changing the view focus which will always change the view origin.
There are four basic ways to directly change the view origin:
- Moves view origin on the x/y plane (yellow). Press/hold Space+ and move the mouse
- foward/back: moves view origin up/down on the y axis.
- left/right: moves view origin left/right on the x axis.
Note: Panning speed is defined by the distance between view origin and view focus: The closer the view origin is located to the view focus the slower mouse movement is translated to the view origin.
- Moves view origin on the x/z plane (magenta). Press/hold Space+ and move the mouse
- foward/back: moves view origin forward/back on the z axis (zooming).
- left/right: moves view origin left/right on the x axis (panning).
- Rotates view origin around the view focus. Press/hold Space++ and move the mouse
- foward/back: rotates view origin up/down along the longitude lines of a sphere that has the view focus as origin.
- left/right: rotates view origin left/right along the latitude lines of a sphere that has the view focus as origin.
- Zooming out
- Finally, you can zoom out of the view focus without changing it by pressing Ctrl+Space+. The position of the mouse pointer doesn't matter.
Note how panning does not only change view origin but also view focus. If the view origin is changed on x or y axis view focus changes in relation to that.
There are four ways to change the view focus and, in consequence, view origin. All of these ways set a new view focus but the view origin is adjusted in different ways:
- Hold Space and double-click on the point you want to position the view focus on. View focus is changed to the selected point view origin changes relative to the change of view focus.
- Select the item you want to focus on in the viewport and press ⇧ Shift+C. View focus is changed to the origin of the selected item and view origin changes relative to the change of view focus.
- Select the item you want to focus on in the viewport and press A. View focus is changed to the center of the selected item and view origin basically changes relative to the change of view focus but the distance between view origin and view focus is adjusted so that the entire entity can be viewed in the viewport.
- Zooming in
- Move the mouse cursor to the point you want to focus on and press Ctrl+Space+. View focus is changed to the selected point and view origin changes relative to the change of view focus while zomming in one step.
Fly mode vs. Seamless mode
Fly mode is easily accessible for most users, whereas seamless mode is more difficult to master. However, in comparison to seamless mode there are two major downsides to fly mode:
- The more you map the more uncomfortable it will become to constantly switch between editing and fly mode.
- You can only control view origin in fly mode, view focus is moved relatively to the change of the view origin. This means that panning, zooming/panning, and particularly rotating becomes unusable in many cases because the view focus will not be positioned on the entity that you want to work on when deactivating fly mode.
Zoom Status / Grid
Even though technically not part of viewport navigation, the zoom status is also covered in this article because it is defined by viewport navigation. You may already have noticed that the grid lines on the x/z plane change in relation to viewport navigation. That is due to the fact that the division of the grid is relative to the zoom status of viewport navigation. In other terms:
The closer view origin is located to view focus, i.e. the closer you zoom in on the view focus, the smaller the grid division will become. This makes sense because grid division controls snap points for positioning of elements and the closer you zoom in on an object the more likely it is that you want to fine-tune the focussed part of your content.
Needless to say that this relation between viewport navigation and zoom status only works in seamless mode because fly mode does not influence zoom status.