Multi-View Perspective refers to perspective systems, images or groups of images that provide more than one view, viewpoint or aspect of a spatial object, scene or environment. Instead of restricting representation to one fixed view, a multi-view system can reveal different parts, sides, directions or aspects as the viewpoint changes, or can present several views simultaneously.
The term covers several distinct arrangements. The Dictionary of Perspective identifies four principal types: changing-viewpoint perspective, multiple-object perspective, orthographic multi-view perspective, and linked or explorable New Media multi-view perspective.
1. Changing-Viewpoint Multi-View Perspective
The first type concerns a single object or scene viewed from changing viewpoints. As the observer, camera or virtual viewpoint moves, previously hidden surfaces or scene details become visible while others disappear.
A moving film camera provides a familiar example. A sequence of camera positions produces successive perspective views of the same environment. CAD systems, 3-D modelling programs and computer games similarly allow a virtual observer to move around or through a digital scene and generate new perspective views continuously.
This type demonstrates an important principle: a three-dimensional scene cannot normally be completely described by a single perspective image. Changing the viewpoint reveals further spatial information.
2. Multiple-Object Perspective
The second type concerns a scene containing multiple objects presented from differing aspects. Even when an observer or camera occupies one fixed position, objects distributed throughout a scene can be oriented differently relative to that viewpoint.
Each object therefore presents its own particular aspect. A complex scene can contain many component perspective relationships simultaneously, even though all are contained within one overall view.
This can also be called Multiple Aspect Perspective or Composite Viewing Angle Perspective. It draws attention to the fact that a perspective image need not contain only one simple object-to-viewer relationship.
3. Orthographic Multi-View Perspective
In technical and engineering drawing, orthographic multi-view perspective represents an object through several coordinated views rather than through one pictorial view.
Principal views can include:
- plan views;
- elevation views;
- sectional views;
- auxiliary views;
- inclined views.
First-angle and third-angle projection systems organise these views systematically so that different sides of the same object can be read together. See also Orthographic Perspective and Parallel Perspective.
4. Explorable Multi-View Perspective
Digital and New Media Perspective systems can link very large numbers of individual views into an explorable spatial environment. The user can move between viewpoints, directions, scales and locations rather than being restricted to one predetermined image.
Such systems may combine navigation, way-finding, position, scale, direction and contextual information with the displayed perspective views. Digital maps, virtual environments, computer games and navigable 3-D models are examples of systems in which many individual perspectives can be organised into a larger visual structure.
Multi-view perspective is therefore particularly important in interactive media because the relationship between views becomes part of the perspective system itself.
Moving and Stationary Multi-View Perspective
Multi-view systems do not necessarily require the observer to move. Multi-View Stationary Perspective provides several optical views or aspects of the same object or scene while the observer remains at essentially the same station point.
A multiple-mirror arrangement provides a simple physical example. Several mirrors angled differently towards the observer can simultaneously reveal the front, side and rear aspects of a person or object. This connects Multi-View Perspective directly with Mirror Perspective.
Digital systems can achieve a comparable result by gathering, displaying or linking multiple views within a single interface.
Multi-View Flat Perspective
A particularly difficult representational problem is the attempt to make a single flat image work convincingly from more than one viewing position. The Dictionary records Leonardo da Vinci’s investigation of paintings intended to provide apparently appropriate spatial views from different positions occupied by a moving observer.
This exposes a fundamental limitation of ordinary fixed-viewpoint perspective: a geometrically constructed image is normally organised for a particular eye point or viewing relationship. Designing one flat image to satisfy several substantially different viewing positions therefore requires some form of modification, compromise or special construction.
Multi-View, Spherical and Panoramic Perspective
Spherical Perspective and Panoramic Perspective are closely related to multi-view systems because they can encompass very large angular fields and allow many directional views to be represented or explored.
A spherical or 360-degree system may enable the observer to look around from a viewpoint, while a system based on movement around an object can reveal successive aspects of that object. These are different spatial operations, but both extend perspective beyond the conventional idea of one fixed rectangular view.
Multi-View is Not the Same as Multi-Point
Multi-View Perspective should not be confused with Multi-Point Perspective. The number of viewpoints and the number of vanishing points describe different properties of a perspective system.
A single fixed viewpoint can generate several vanishing points, while a multi-view system may consist of many separate views, each formed from its own viewpoint. Multi-view therefore concerns the organisation or availability of multiple views or aspects, not simply the number of vanishing points within an image.
Applications of Multi-View Perspective
Multi-View Perspective occurs across art, science and technology, including:
- technical and engineering drawing;
- CAD and 3-D modelling;
- cinema and moving-camera imagery;
- computer games and virtual environments;
- interactive maps and spatial navigation;
- 360-degree and panoramic imaging;
- multi-camera imaging systems;
- mirror and multi-mirror arrangements;
- scientific and technical visualisation;
- artworks combining several viewpoints or aspects.
The underlying principle is the same: spatial information is distributed across more than one view, aspect or viewpoint rather than being confined to a single fixed perspective.