The main purpose of this work presented in this paper, is the possibility to optimisea road construction using visualisation in 3D, in a scale 1:1. With virtual realitytechnology, we can visualise the whole road and the environment around. Therefore thepossibility to control the position of traffic signals, SOS telephone cabs, noise-protectionroad walls, safety exits, tunnels height or eventual bridges during the virtual visit of theroad. In the same time, we can control the visibility of the road by driver, from start till theend of the road. Doing this, we can help architects, technicians and civil engineeringgroup to modify their plans before they start to construct the real road.In this sense, we can contribute to make the work properly from the beginning,instead of doing several interventions to modify the road that are usually done once theroad is over. Of course, the cost of such interventions is very high and in the same timethe traffic is stopped.Concretly, we realised the A5 highway application. Besides the modelisation withtextures and visualisation of the road, we added the interactivity in real time through adriver of a virtual car. This application run very well, presenting a high degree of virtualreality

Besnik CAMAJ

Etienne PETREMAND

Epoka University

“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.399Optimisation of a road construction using 3D visualisationBesnik CAMAJ, Etienne PETREMANDSoftware Engineering Department, University of Applied Sciences of Western Switzerland (HEIG-VD), I ICT – CAP3D, Yverdon les-Bains, SwitzerlandEmail: besnik.camaj@heig-vd.ch – Phone : +41(76)3414341Software Engineering Department, University of Applied Sciences of Western Switzerland (HEIG-VD), I ICT – CAP3D, Yverdon les-Bains, SwitzerlandEmail: etienne.petremand@heig-vd.ch – Phone : +41(24) 5577563ABSTRACTThe main purpose of this work presented in this paper, is the possibility to optimisea road construction using visualisation in 3D, in a scale 1:1. With virtual realitytechnology, we can visualise the whole road and the environment around. Therefore thepossibility to control the position of traffic signals, SOS telephone cabs, noise-protectionroad walls, safety exits, tunnels height or eventual bridges during the virtual visit of theroad. In the same time, we can control the visibility of the road by driver, from start till theend of the road. Doing this, we can help architects, technicians and civil engineeringgroup to modify their plans before they start to construct the real road.In this sense, we can contribute to make the work properly from the beginning,instead of doing several interventions to modify the road that are usually done once theroad is over. Of course, the cost of such interventions is very high and in the same timethe traffic is stopped.Concretly, we realised the A5 highway application. Besides the modelisation withtextures and visualisation of the road, we added the interactivity in real time through adriver of a virtual car. This application run very well, presenting a high degree of virtualreality.INTRODUCTIONLocated at the heart of Europe, Switzerland is dependent on modern transportinfrastructure and efficient communications and networks. It presents over 71000 kmroads, 3100 bridges and 250 tunnels [1]. This infrastructure is an important prerequisitefor the country's cohesion and for exchanges with other countries and economicprosperity. In Figure 1, is given a map that shows a network of europian roads traversingSwitzerland [2]. The decisions taken by Federal Department of the Environment,Transport, Energy and Communications are prepared in the various federal offices like:Office of Energy, Office of Communications, Roads Federal Office, Office of Transportetc.“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.400Figure 1: A map with europian roads traversing SwitzerlandIndeed, after published announce for a road construction, the Federal Department ofRoads Office (FEDRO), get the offers from several road constructors. This departmentworks closely together with engineers consortium and cantonal civil engineeringdepartments for the construction, operation and maintenance of roads.Then the work is attributed to contractors and several sub-contractors. Each roadconstructor has to respect the rules of road (norms SIA and VSS). Of course, quality ofwork depends on the planning, organisation and coordination of works. The architects areused to design their concepts in a formal way, due to their standards, without taking careof the civil engineering details. Civil engineering has different tools to construct a road. Alot of constraints have to be considered, especially safety in roadso variable message signso emergency call telephones SOSo wide protection gallery against falling rocks safety in road tunnelso ventilation, escape facilities, traffic flow , traffic management, escapefacilities in twin tube tunnels, regularly spaced cross connections, selfclosing doors, high capacity massive smoke extraction system, trafficsignalling equipment lighting of road infrastructure, etc.Due to the complexity of the management process and inherence of the traditionalplanning tools, construction managers are still having problems to get accurate results.“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.401In this sense, we were motivated to find a good solution. We proposed to build a threedimensions visual simulation of a construction process, integrating all construction plans.Visualisation is already recognised as one of the most important tools for achieving thispurpose. The simulation might assist a planner and the construction managers in a betterperception of a project. They can visualise the road and it’s environment before the realconstruction of the road. Being there virtually, they can find and modify the eventualerrors. In this way, they can reduce the cost of the construction and optimise wholeprocess.APPLICATION A5, WHAT AND HOW WE DID?Our application is a real time application and is demonstrated with a real life case study ina road project A5, which is a highway between Neuchatel and Yverdon-les-Bains.Creating a real time application program, we took care of an important database whichstands in theo image generator performance ( polygons-per-frame textures)o visual database as a geometrical representation (polygones).To realise an amount of visualisation (example: a piece of terrain) we do need the altitudedata file which is simplified and then triangulated to create a mesh. Then, we can texturethese surfaces with the corresponding images that are taken from reality. In this way wehave an OpenFlight 3D file format which we use for visualising our application. Thisprocess is given in the figure below.Figure 2: The process of realising of an amount of visualisationTo create a realtime 3D models for visual simulation, we used MultiGen Creator. Creatoris a software package designed specifically to easy construct, to import, structure, edit,prototype, and optimize model databases for use in both large scale visual simulations andentertainment environments [3]. It adds special characteristics to the data structure likeDegrees of Freedom (DOF) and Levels of Detail (LOD).ALTITUDE FILE DATA TRIANGULATIONSIMPLIFICATION TEXTURE.FLT“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.402Figure 3: Multigen Creator user interfaceIn the figure below, we can see three levels of details: LOD 1, LOD 2, LOD 3. Thepolygon mesh is more dense near the point of view P. With different levels of degree, wecan still preserve the visual quality by reducing the number of polygones in order to havemore efficient realtime rendering.Figure 4: Creating the terrain model with Multigen CreatorBy adding any graphical item to the model, MultiGen Creator inherently constructs thedatabase structure. This structure describes the hierarchical link between faces, polygones,objects, nodes, groups and database nodes. We can observe it in a lower part of usergraphical interface of Creator.“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.403To store the information, MultiGen Creator uses the public domain OpenFlight format.Creator and OpenFlight are double precision, allowing as much accuracy as necessarywhen describing complex objects and very large area databases [3].SCENEGRAPHTo reduce memory budget of our application and to increase the speed of execution, weuse the scenegraph to describe the virtual 3D worlds. The scenegraph is a spatialrepresentation of a graphical scene which defines a logical relationship between variousentities of the virtual 3D environment. Applying the scenegraph (Figure 5), we realised ahigh visual performance of our application.To visualise the application, we used OpenSceneGraph. OpenSceneGraph is based aroundthe concept of a scenegraph providing an object-oriented framework on top of OpenGL. Itis an OpenSource, cross-platform graphics toolkit for the development of high-performance graphics applications [4].Figure 5: A scenegraph of a visual simulationTRAFFIC CONTROL SIGNSTraffic control signs are placed respecting the rules of traffic. As we mentioned above,there can be a clear mismatch between plans from sub-constructors offices. For example,from plans coming from two different offices, we found that they placed an emergencycall station (SOS telephone) behind a protection wall of two mettres high! Onceconstructed, there are to much efforts and costs to modify these constructions. Anotherexample is the non adapted position of ventilators in tunnels. Position of ventilators isvery sensitive in the sense that ventilation and extraction systems must reduce the build-upof smoke and evacuate it as efficiently as possible. Or the non adapted position of safetytraffic signs, for example the speed limit sign. The speed limit should be considered as anintegrated requirement to be respected all of the time. But, unfortunately, exeeding thespeed allowed is an usual event today. In this case, the driver may not observe all of safetytraffic signs. And of course, sometimes this leads to an accident with hard consequences.So, having the possibility to visualise a whole road environment and virtualy driving in,gives a chance to displace these signs in a right place. In our application A5, we can move“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.404traffic signs in a position we like. The exactly position of a traffic sign is given on a top ofdisplay in X,Y,Z coordinates, it’s distance from the starting point of highway and thevector of translation . This situation is shown in figure below [5].Figure 6: Displacement of traffic signs on a highway A5Once we are sure that everything is in it’s place, we can show it to the architects,technicians and civil engineering groups to modify their plans before they start toconstruct the real road. In this way, from the beggining, we can contribute to make thework properly, instead of making interventions afterwards, modifying the road that areusually very expensive.INTERACTIVITYAfter the modelisation with textures and visualisation of whole environment of road, weadded the interactivity in real time, through a driver of a virtual car.As an input device we used foce feedback steering wheel with three pedals. For sound, wechoosed the OpenAL, which is a cross-platform 3D audio library used in many types of“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.405audio applications. Car dynamics is controled by motor engine Ageia PhysX, which takescare of solid dynamics, fluid dynamics and collision detection.But to have better performance in visualisation, we had to adapt the source of the code.For example, displacing the car ahead. Below, you can see the adapted equation weimplement to find the best distance of displacing the car virtually. mt*A*21t* vD 2 (1)D- distance of displacing, v - vehicle speed, ∆t – time difference, A - vehicleacceleration.As about user interface, we can see and control all vehicle parameters, directly on to theinterface of our applications (Figure 7).Figure 7: A snapshot with all parameters of the vehicle running on A5Well, integrating all this, we made an immersive visual simulation that is safe alternativeto evaluate feasibility or to test physically the still non realised road environments.Another good point of visual simulation is that we can visualise the different solutions of aspecific situation and comparing them we are able to choose the best one.CONCLUSIONOur objective was to develop an application improving the visual simulation may optimisea road construction. Charged from Federal Department of Roads Office, we did theapplication named A5. it is obviosly we found some technical difficulties in constructionplans. The civil engineering group was very satisfied because they traditionally uses two“1st International Symposium on Computing in Informatics and Mathematics (ISCIM 2011)”in Collabaration between EPOKA University and “Aleksandër Moisiu” University of Durrëson June  2-4 2011, Tirana-Durres, ALBANIA.406dimensional visualisation techniques. Making an experience through virtual 3D roadenvironments, with the interactivity in real time, helps to have efficient constructionscheduling and plans before starting the real construction of the road.REFERENCES[1] http://www.nynas.com/templates/Page____10514.aspx?epslanguage=ENSwitzerland, Road Statistics.[2] http://www.astra.admin.ch/index.html?lang=enNational roads, Motorway and main roads, Plan of completed network, FEDRO.[3] http://www.modelbenders.com/ein5255/MG25_Tutor.pdfThe MultiGen Creator, Chapter 1, pp 1-1 and 1-5.[4] http://www.openscenegraph.org/projects/osg/wiki/About/IntroductionIntroduction.[5] http://cap3d.heig-vd.ch/display.php?page=fr/proj2.php&pos=0Projets, Prototypage virtuel, Autoroute A5.

Optimisation of a road construction using 3D visualisation

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Optimisation of a road construction using 3D visualisation

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