You can use the mouse to manually zoom, pan, or rotate the model. Additionally, you can rotate the model by using the ViewCube, and walk through your model in 3D views.
Scroll in or out with the middle mouse button.
Right-click anywhere within the view.
In the context menu, select Zoom Out.
You can also use the keyboard shorcut ZA to zoom extents.
You can use the ViewCube to adjust the view. However, if none of the standard ViewCube are appropriate, you can also rotate the model manually.
Click the required vertex on the ViewCube.
If the required vertex is not visible, click one of the other vertices to spin the ViewCube until you can see the required vertex.
Click the required edge on the ViewCube.
If the required edge is not visible, spin the ViewCube by clicking the vertex that is adjacent to the required edge.
If the required face is not visible, spin the ViewCube by clicking the vertex adjacent to the required face.
To move forward, backward, left or right, use the arrow keys.
To move up and down, use the Q and Z keys.
To rotate the view, hold down the right mouse button and drag the view.
To exit Walk mode, press Esc.