What is Toposcopy?

Toposcopy is a new design and visualization method, combining photographic or video images with spatial designs, 2D maps and elevation data. During the fieldwork images are preferably taken with a toposcope, that allows to measure some visible 3D points at the same time. However when you have access to an up-to-date map with some elevation data you can also  take pictures using a regular tripod. During the processing of the data the images are linked to the 2D map to form one interactive 3D system. After that spatial designs can be visualized in the existing environment very accurately, also in rural areas with few orientation points. Moreover the 3D system can be used for measurements. Toposcopy is a new photogrammetric method that needs just one photo and a 2D map to acquire 3D data. The method is well documented with papers in English. To get in depth information you may want to read a paper from 2003 and a second paper from 2004 both published by the International Society for Photogrammetry and Remote Sensing (ISPRS).
3D models of urban areas in CityGML en VRML.
As research partner in the GIMCIW project guided by Sisi Zlatanova, Assistant Professor of GISt, OTB,TU Delft, we started in 2007 with the development of an export in CityGML as an addition to the export in the Virtual Reality Modeling Language (VRML) and the Drawing Exchange Format (DXF). CityGML is a new and important standard for the modeling and exchange of 3D city and landscape models and data. Just like in toposcopy.the buildings are classified according to the shape of the roof. With the photogrammetric possibilities Toposcopy is a good modeling tool for CityGML. That is reviewed in a paper for the GSDI 11 world conference held in Rotterdam, The Netherlands. In contrast to for example VRML, CityGML is based on a rich, general purpose information model in addition to geometry and graphics content. Nevertheless VRML is still a valuable format, because it can be imported in advanced visualization programs like 3D Studio Max and Maya (see the animation). Models that are exported in VRML can also be placed easily on Google Earth. It is also possible to place photorealistic trees in VRML worlds on so called billboards that automatically turn perpendicular to the line of sight. We have not been able yet to code something like that in CityGML
The figure above shows part of the campus of the Delft university, that is modeled with Toposcopy and exported in CityGML. The buildings are projected on an aerial photo. The highest building is in Level of Detail 1 (LOD1). The other buildings are exported in LOD2. More information about CityGML can be found in http://en.wikipedia.org/wiki/CityGML and  http://kennis.rgi.nl/ , project nr 029.
3D topographic dataset in CityGML
The different layers of the TOP10 vector database are made 3-dimensional by combining the data with the AHN (Dutch elevation points) using the 3D Analyst extension of ArcGIS. The result is a collection of 3D polygons, that are imported in het Scope program and exported in CityGML
Most buildings are modeled by automatically extruding the polygons of hzn-files in a vertikal direction with a fixed height. Some monuments are modeled with Toposcopy and textured with photo images.
Façade drawings with photogrammetric precision
Toposcopy is a good alternative for terrestrial laserscanning in making façade drawings of existing buildings.. Look for more information at a  ISPRS publication of 2003 or an article in the GIM-magazine.
Accurate 3D models in 1/3 of the time
ScopeK.JPG  (151065 bytes) The adjacent picture shows the program Scope with a loaded photo. The program works with parametric virtual models of buildings with different rooftypes. That makes it very easy to build a virtual maquette of the existing environment by alternately clicking on points in the map and a photo. All parametric 3D points are calculated directly and saved in the Microsoft Access database. By combining models more complex buildings can be constructed. Because the images are linked to the map, it is possible to calculate the location of each visible 3D point in the photo. Therefore a face of the model can automatically be mapped with part of the photo that is used to construct the model.
korenbeurs.jpg (139224 bytes) You can walk interactively through the toposcopic model of the Korenmarkt in the town of Arnhem by clicking on the adjacent photo, supposed that on your computer a VRML browser is installed. Otherwise you may want to download the cortona client on: http://www.parallelgraphics.com/products/cortona/. It may take some time to load all the textures.. The korenmarkt model is also used to practice the programming in CityGML. By clicking on the name Korenmarkt you can download the CityGML code with all the textures. The model can be viewed with the Autodesk LandXplorer CityGML Viewer van 3D Geo GmbH ( http://www.3dgeo.de ).
Meten in bewegende beelden.
The Dutch road department has over the years used colliding buses under controlled conditions to test different barriers and guard rails. During these tests video recordings were taken. With toposcopy the movements of the bus and distortion of barriers and rails were measured to determine the space behind the barriers that must for safety reasons be kept free of obstacles.The possibility to measure in old video frames is the more interesting because nowadays video cameras are extensively used to monitor traffic on roads, waterways, townsquares and around buildings. More information can be found in an article in GIM international.
Collision trial with a bus
Accurate photorealistic visualizations in the existing environment
Toposcopy is a dependable and professional method to make accurate 2D photorealistic visualizations of spatial designs in the existing environment. Toposcopy is particularly important for visualizations in areas, where few points can be indicated both in the photo and the map and when you do not have enough elevation data. When you work with a toposcope you can always add the missing data yourself with a few measurements. That way photorealistic visualizations get the accuracy of landsurvey!.
The principle is explained in the adjacent pictures. A toposcopic project usually consists of a 2D map, one or more photos of the existing environment and a spatial design, that is drawn in the map. A new design is drawn in the map and is also spatially described in the database. The 3D information of the toposcopic database can be shown in perspective on top of the photo.

Realistic trees, taken from a ‘tree library’  can be drawn on top of the photo. Photo plus perspective are imported into a Paint program and further elaborated. These trees can also be used in 3D models. In that case they are placed on transparent billboards, that are always perpendicular to the direction of view as is shown in the panorama’s below.

In such a way one can also show the effect of a road or railway on the surrounding landscape from a particular standpoint. Such visualizations are made in a short time and are excellent for Environmental Impact Statements showing various alternatives, to evaluate a design and properly inform the public. Voor meer informatie zie  Agro-Informaticareeks nr.13, oktober 2002, blz 91-98.

Plattegrond Foto
Perspectief Visualisatie
Toposcopic 3D world as a base for an animation
With Toposcopy it is quite easy to make an accurate  3D maquette of an infrastructural design in an early stage and relate it to the landsurvey data of the existing environment. In cooperation with Geo Plus and Artificial Industry we made a visualization of the proposed Julianaplein in the Netherlands. Geo Plus has calculated the course of the roads in the MX program.We made it into a 3D model including the buildings in the area. Artifical Industry imported the model in Maya elaborated it further and made an animation from it.
Video van het Julianaplein
Panoramas as a background of a virtual world
If you click on the adjacent picture, the VRML client opens a cosmorama, that shows the design for the brook area in 3D and in a very realistic way. At first the viewer is standing in the middle of the area and can look around. It is also possible to walk in the virtual model. A 360 degrees panorama is used as a background.
Present Industrial area Future, natural looking brook area
It is also possible to work with panoramas, in which only 2,or 3 photo’s are stitched together. With such panorama’s the existing environment does not always have to be described in 3 dimensions.
A  toposcopic photo or panorama can even be used as a background of a flash animation. With the visualization of the Julianaplein in Groningen  toposcopic panorama’s were combined with animations made in Maya.
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