Explanation of Data Types

Making our 3D Models and GIS data interactive on this website is currently in progress. Until this is achieved screenshots and animations of the data are provided to give you an impression of the various data types the Zamani Project produces. Following is a full list of what is produced. Please browse through the links in the text or use the menu on the left to see examples of each Data Type.

3D Models

3D models are three-dimensional scaled visual representations of physical objects in digital form. Surfaces of 3D models are represented by polygons, generally in triangle form which are created by linking neighboring points of a point cloud. The level of represented detail varies and is differentiated by resolution. "High", "medium" or "low resolution" models are generated for each site. The data is usually acquired with laser-scanners. To view some examples see 3D Model Screenshots- or the Animations-section.

Laser Scans

A laser scanner accurately determines the space position of millions of surface points on an object, thus creating a three dimensional point cloud representing the object. When displayed on a computer screen, point clouds provide a visual impression of the objects surface. The colour of each point usually denotes the intensity value of the return signal to the laser scanner. Individual point clouds of an object can be combined and processed to create a full 3D model. Wherever possible the entire site is laser scanned. Where the extent of a site makes this impossible, prominentstructures are selected for scanning.

Plans - Sections and Elevations

Horizontal cuts through a 3D model show plan views of ground, roof or intermediate levels. Vertical cuts through the model are shown as sections and vertical views from the outside of an object are shown as elevations. Sections and Elevations include scale and orientation and can be used for measurements. Sample sections are produced for each site but any additional sections can be generated as required. Sections and Plans can be viewed here.

Geographical Information Systems

A Geographical Information System (GIS) consists of spatially referenced information about the natural and man-made environment. GISs are created by assembling diverse geographically referenced data of topographical or general thematic nature in a digital database. The information is displayed in map form and can be managed, interrogated and analyzed through user interfaces which show the relationship between different map layers. Satellite images, contours, rivers and plans are examples of layer information in a GIS. A GIS is generated for each documented site and can be used for site management, for conservation and restoration projects, or for general inspection of the site and surrounds. GIS Layouts can be viewed here.

3D Landscape Models and Remote Sensing

Aerial photogrammetric images and satellite images, where available, are used in combination with existing contour data, SRTM data and Aster data to create 3D landscape models of the terrain surrounding a site. They are also used in the GIS of the site.

Contextual Images and Videos

Digital images and videos of each site are taken to capture the current physical environment surrounding the structures of a heritage site. Samples can be viewed in our Picture Gallery

Photogrammetric Images

Photogrammetry is the process of measuring 3D co-ordinates of an object, or of the earth's surface, using two or more photographs taken from different positions. Analog or digital photographs are captured with specialized metric cameras or calibrated amateur cameras. Imperfections in the lens and camera body cause distortion in the photograph. A camera calibration is used to mathematically undistort or rectify the images so that mathematical models can be used to calculate metrically correct 3D coordinates of the photographed object or surface area. Photogrammetric images are captured for important structures and can be used for additional measurements of detail if required.

Stereo Pairs

Stereo pairs are special cases of photogrammetric images where two images of the same object or scene are captured from different positions with near parallel orientation. This emulates the process of human 3D vision. The effect of three dimensionality can be achieved by viewing the images through a stereoscope or similar device. Stereo images are provided for important structures of a site to allow 3D viewing and measurement of detail.

Panoramas

Panoramas are images with a very broad horizontal and vertical range of view. The term is used specifically for photographs that show a wide view produced by a panoramic camera or by joining photographs together. Full dome panoramas capture a full 360 degree view of a position and can be viewed in appropriate software to afford the user 360 degrees of the area surrounding the panorama position. Panoramas can be integrated into a panorama tour so a user can move from panorama position to panorama position thus allowing a virtual tour of the site. A selection of sites can be explored with this technique in our Panorama-Tours section.