Explanations of various output data
produced by the Zamani project
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.
A laser scanner accurately determines the position of millions of surface points on an object, creating a three dimensional point cloud of the object. When displayed on a computer screen, point clouds provide a visual impression of an object's surface. The colour of each point denotes the intensity of the return signal to the laser scanner. An object's individual point clouds can be combined and processed to create a full 3D model.
Virtual Worlds enable users to interactively walk around 3D virtual envrionments of heritage sites based on data captured on site and processed by the Zamani Project. Virtual Worlds can be viewed here. The Unity webplayer will need to be installed on your browser, and is currently not compatible with Google Chrome.
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 additional sections can be generated as require.
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.
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 heirtage site. Samples can be viewed in our Picture Gallery.
Panoramas are images with very broad horizontal and vertical ranges of view. Full dome panoramas capture a full 360 degree view of a position and are create by joining pictures together. Panoramas can be intergrated into a virtual world.
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 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.