DATA TYPES


Explanations of various output data
produced by the Zamani project

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. Examples:
> 3D Models
> Virtual Worlds
> 3D Model Screenshots
> Animation-Gallery

POINT CLOUDS


A laser scanner accurately determines the space position of millions of surface points on an object, creating a three dimensional point cloud representing the object. Displayed on a screen, point clouds provide visual impressions of surfaces of objects and, in this case, monuments. The colour of each point in the diagram (left) denotes the intensity of the return signal to the laser scanner. Individual point clouds of an object can be combined to create a full 3D model. Point clouds can also be generated by photogrammetric methods, such as the SfM (Structure-from-Motion) technique. The Zamani project employs SfM to fill holes in areas where laser scanners cannot reach.

VIRTUAL WORLDS


Virtual Worlds enable users to interactively walk around 3D virtual envrionments of heritage sites. The Zamni Team created such Virtual Worlds for some sites based on 3D dimensional models for these sites. Installation of the Unity webplayer into the browser is required to visit the Virtual World.
> Virtual Worlds

PLANS - SECTIONS AND ELEVATIONS


Horizontal cuts through a 3D model show plan views of ground, roof or intermediate levels. Vertical cuts through the model result in sections and shown elevations. Sections and Elevations, as produced here 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

GEOGRAPHICAL INFORMATION SYSTEMS


A Geographical Information System (GIS) consists of spatially referenced information about a natural and/or 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 site and can be used for general site management, conservation and restoration projects.      > GIS Layouts

3D LANDSCAPE MODELS AND REMOTE SENSING


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

PANORAMAS AND PANORAMA TOURS


Panoramas are images with very wide horizontal and vertical ranges of view. Full dome panoramas capture a full 360-degree view from a single position and can be viewed in appropriate software to afford the user 360 degrees view of the area surrounding the panorama position. They are created by joining a series of wide-angle images. Individual panoramas can be merged into a panorama tour, which allows a user to freely move from one panorama position to another. Sites can be explored with this technique in our
> Panorama Tours

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

PHOTOGRAMMETRIC METHODS


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 areas. Photogrammetric images are captured for important structures and can be used for additional measurements of detail if required. Structure-from-Motion (see Point Cloud) software typically allows for the use of uncalibrated cameras by integrating a lens correction model into the software.