Camera Preferences

General

Number of Undo Levels

Sets the number times you can consecutively undo camera/viewpoint moves in a 3D view.

Mouse Wheel

Wheel Zoom

Controls how the mouse wheel is used for zooming in the 3D views, fcurve editor, animation mixer, Fx tree, render tree, ICE tree, schematic and texture editor:

Off. The mouse wheel does not zoom.
On. Scroll forward to zoom in and backward to zoom out. Press Ctrl to zoom quickly, Shift to zoom slowly, and Ctrl+Shift to zoom even more slowly.

However, you cannot use the mouse wheel in other tools, for example, to set the radius for the brush or proportional modification; instead, press R and drag the mouse to modify the radius.
Navigation Only. Uses the mouse wheel to scroll only while the Navigation tool is active (S key, or Alt key with Maya interaction or when the Use Alt key for view navigation preference is on). This allows you to use the mouse wheel in other tools and still use it to zoom.

Zoom Rate

The base zoom speed for zooming with the mouse wheel. You can modify this during interaction by pressing Ctrl (faster), Shift (slower), or Ctrl+Shift (extra slowly).

Zoom on Cursor

When activated, zooming with the mouse wheel focuses on the mouse pointer position instead of the view's center.

Pan/Zoom

Zoom In/Out	Sets the rate for zooming in units per second higher values cause faster zooming, and vice-versa.
Zoom on Cursor	When activated, zooming in focuses on the mouse pointer position instead of the view's center.

Nav

Mouse Mapping	Specifies how the mouse buttons are mapped when the Nav tool (S key) is activated. You can choose the standard Softimage mapping or the Maya mapping. Softimage Mouse Mapping: Left Mouse Button: Tracking/Pan Middle Mouse Button: Zoom/Dolly Right Mouse Button: Orbit Shift + Left Mouse Button: Constrained Tracking/Pan Shift + Middle Mouse Button: Roll Shift + Right Mouse Button: Constrained Orbit Ctrl + Left Mouse Button: Rect Zoom (drag left to right to zoom in and right to left to zoom out) Ctrl + Middle Mouse Button: Rect Zoom Out Maya Mouse Mapping: Left Mouse Button: Orbit Middle Mouse Button: Tracking/Pan Right Mouse Button: Zoom/Dolly Shift + Left Mouse Button: Constrained Orbit Shift + Middle Mouse Button: Constrained Pan Shift + Right Mouse Button: Roll Ctrl + Left Mouse Button: Rect Zoom (drag left to right to zoom in and right to left to zoom out) Ctrl + Middle Mouse Button: Rect Zoom Out
Use Alt Key for View Navigation like Maya	When on, you can activate the Nav tool by holding down the Alt key. The tool will obey the mouse mapping specified by the Mouse Mapping setting.
Use Middle Mouse Button for View Navigation like 3ds Max	When on, you can: Middle-click and drag to pan or track. Alt+middle-click and drag to orbit (3D views only). Ctrl+Alt+middle-click and drag to zoom. This works in 3D views like the viewports and object views, as well as the following 2D views: schematic fcurve editor dopesheet UV texture editor FxTree (compositor) animation mixer LipSync view render tree ICE tree
Orbit Around Selection	These options control whether the camera orbits selected components or the normal camera interest. Off: the orbit tool will always orbit around the camera's point of interest. On: if you are in object selection mode, the orbit tool orbits the camera around the selected object, rather than the normal camera interest. If you are in component selection mode, using the orbit tool orbits the camera about the selected components. Components Only: if you are in object selection mode, the orbit tool orbits the camera around the normal camera interest. If you are in component selection mode, using the orbit tool orbits the camera about the selected components.
Orbit Speed	Changes the speed at which the Nav tool's Orbit function orbits. Increasing the value increases the speed.
Pan Speed	Changes the speed at which the Nav tool's Pan function pans. Increasing the value increases the speed.
Zoom/Dolly Speed	Changes the speed at which the Nav tool's Zoom/Dolly function zooms and dollies. Increasing the value increases the speed.

Walk/Fly

Look Speed	Controls the speed for "looking" with the mouse, in units per second, while using the Walk or Fly tools. Higher values cause faster movement ad vice-versa.
Forward	Controls the speed for forward and backward motion, in units per second, while using the Walk or Fly tools. Higher values cause faster movement ad vice-versa.
Sideways	Controls the speed for leftward and rightward motion, in units per second, while using the Walk or Fly tools. Higher values cause faster movement ad vice-versa.
Slow Multiplier	The factor by which speed is adjusted for slow movement (Middle Mouse Button) while using the Walk or Fly tools.
Fast Multiplier	The factor by which speed is adjusted for fast movement (Right Mouse Button) while using the Walk or Fly tools.

Drive

Speed	Specifies the acceleration factor for the Drive tool.
Turn (deg/sec)	Sets the speed at which the drive tool turns, in degrees per second.
Up/Down (units/sec)	Sets the speed at which the drive tool looks up and down, in units per second.
Show Guide	Displays the overlay guide for the Drive tool.