Camera and Navigation in 3D

How the user moves and points the camera determines whether a 3D visualization is explorable or disorienting.

The camera as viewpoint

In a 3D scene the camera defines what the user sees: its position, the direction it looks, and its projection. Good navigation lets the user reach any informative viewpoint quickly and without getting lost. Poor navigation makes even a beautiful model useless because the viewer cannot control what they see.

Navigation models

• Orbit (turntable): rotate around a target point, the default for inspecting an object.
• Fly and walk: move the camera through a space, suited to interiors.
• Pan and zoom: translate and change scale without rotating.
• Framing: a control that returns to a known, well-composed view.

Projection

Perspective projection matches how we see, giving depth cues but distorting sizes with distance. Orthographic projection preserves parallel lines and true measurements, which is why it is preferred for engineering inspection where comparing sizes matters. Offering both serves different tasks.

Preventing disorientation

Constrain rotation to avoid rolling the world upside down, keep a consistent up direction, animate view changes so the user follows the transition, and always provide a way home. A visible orientation cue (an axis widget) helps the user stay oriented.

Selection and depth

Picking an object in 3D requires resolving depth; hover highlights and clear selection feedback tell the user what they are about to act on, supporting the linked views of a twin interface.

Kronos use

The public machine models default to orbit navigation with an orthographic option and a framing control, so a general audience can inspect the design without getting lost.