Automatic Reconstruction of 3D Building Models from Terrestrial Laser Scanner Data

<jats:p>Abstract. With modern 3D laser scanners we can acquire a large amount of 3D data in only a few minutes. This technology results in a growing number of applications ranging from the digitalization of historical artifacts to facial authentication. The modeling process demands a lot of time and work (Tim Volodine, 2007). In comparison with the other two stages, the acquisition and the registration, the degree of automation of the modeling stage is almost zero. In this paper, we propose a new surface reconstruction technique for buildings to process the data obtained by a 3D laser scanner. These data are called a point cloud which is a collection of points sampled from the surface of a 3D object. Such a point cloud can consist of millions of points. In order to work more efficiently, we worked with simplified models which contain less points and so less details than a point cloud obtained in situ. The goal of this study was to facilitate the modeling process of a building starting from 3D laser scanner data. In order to do this, we wrote two scripts for Rhinoceros 5.0 based on intelligent algorithms. The first script finds the exterior outline of a building. With a minimum of human interaction, there is a thin box drawn around the surface of a wall. This box is able to rotate 360° around an axis in a corner of the wall in search for the points of other walls. In this way we can eliminate noise points. These are unwanted or irrelevant points. If there is an angled roof, the box can also turn around the edge of the wall and the roof. With the different positions of the box we can calculate the exterior outline. The second script draws the interior outline in a surface of a building. By interior outline we mean the outline of the openings like windows or doors. This script is based on the distances between the points and vector characteristics. Two consecutive points with a relative big distance will form the outline of an opening. Once those points are found, the interior outline can be drawn. The designed scripts are able to ensure for simple point clouds: the elimination of almost all noise points and the reconstruction of a CAD model.                     </jats:p>

section_content: This publication sets out the responsibilities and duties of ISPRS Council Members. It had originally been compiled including the statutory duties set out in the Statutes and Bylaws of ISPRS and from the experience of current Council Members. As of version V3. 1 the statutory responsibilities have been omitted to avoid possible inconsistency between the Green Book and the Statutes & Bylaws. The publication of the Book Series -in due time 5. Cooperate with other international organizations concerned with photogrammetry, remote sensing, spatial information science, cartography, geodesy, surveying, and other similar discipline: a. Attend annual meetings of the UN GGIM-Geospatial Societies b. Provide contact of relevant new officers -year 1 6. Represent the Society at international meeting and events a. Attend meetings when appropriate, and communicate with international organizations, e. g. ISC, UN OOSA, UN GGIM-Geospatial Societies b. Maintain passive contact with other organisations c. Attend meetings and communicate with Regional members, multi-national meetings and national members when appropriate d. Represent Guidelines for Registration for ISPRS General Assembly (GA)
section_name: Introduction

section_name: PRESIDENT

section_content: As of 2016. Update needed, e. g. regarding distribution of documents and electronic voting.
section_name: SECRETARY GENERAL

section_content: • Member fees must be paid up to the end of the year prior to the Congress to be eligible to vote. Outstanding fees may be paid in cash up to the commencement of voting. Members are to be advised of this option at least one month prior to the GA. (SG) • Proof of payment -the only acceptable proof of payment will be confirmation of the funds being received in the ISPRS UBS account. Members are to be advised of this at least 3 months before Congress. (SG) • OdMs are to be requested to nominate one delegate and two advisers, and to submit one email address for the purpose of digital voting at least one month prior to the GA. AsMs and RgMs are to be requested to nominate a representative at least one month prior to the GA. (SG) • The SG is to collect the GA documents (GA agenda and all supporting documents) in digital form and forward them to OdMs, AsMs, RgMs and HnMs as well as to Council one month prior to the Congress. The SG will distribute an update of those documents approximately 10 days prior to the Congress. For easy access, these documents will be stored on a separate folder on the dropbox. • The CD is to produce paper copies of all last-minute documents (i. e. those which are not in the dropbox folder, because they came in too late) to be distributed at the GA registration desk. The SG will distribute these documents to all attendees of the GA and also to Council in digital form as soon as they become available. • The SG is to produce a list of GA attendees (delegates and advisers nominated by the OdMs, representatives of AsMs and RgMs, HnM and guests) -for use at the GA registration desk. The list will be forwarded to the CD at least 10 days before the Congress. • From the list of GA attendees, updated by the SG immediately prior to the Congress, the CD will produce GA badges. The CD will deliver the badges to the SG before opening the registration of GA members. • For OdMs, the badges are to be named "Delegate, Country/Region" and "Adviser, Country/Region"; for AsMs and RgMs, the badges are to be named "Representative, Member Name"; for guests (e. g. people bidding for future positions within the ISPRS), the badges are to be named "Guest"; for HnM the badges are to show the name of the HnM and "ISPRS Honorary Member". Council Members and support staff (e. g. Annette, Dan, possibly others) will also receive GA badges, these will come with the label "Council". Furthermore, the CD is to produce a limited number (about 10) of blank badges for GA attendees who failed to register in advance. • The CD is to produce a limited number of paper copies of the GA documents, to be distributed at the GA registration desk, upon request. • Should digital voting not be implemented at the GA, the SG is to prepare voting slipsvoting slip numbers and colours are to vary for each vote and category, respectively. • A link for online participation will be distributed asap prior to the GA to OdMs, AsMs, RgMs, HnMs and others who have registered interest to attend but are detained. SG GA meeting room entrance. Signs will show the way from the Congress to the GA registration. • Ordinary Member delegates and advisers must either o register for the Congress at the Congress registration desk where they will receive a Congress badge, and subsequently register at the GA registration office, where they will receive the GA badge and when necessary, voting slips, or o register at the Congress registration desk for GA only, where they will receive a GA ONLY badge, and subsequently register at the GA registration office, where they will receive voting slips when necessary. o Only delegates or advisors are eligible to collect voting slips (one per OdM).
section_name: Preparation

section_content: • A letter from the OdM's office, naming nominated delegate and advisers, must be produced at the GA registration office as proof of eligibility to represent that OdM. If requested, the delegate and the advisers must prove identification (e. g. passport). 

3. Registration of AsMs, RgMs, HnMs, and Guests • AsMs and RgMs and representatives must either: o register for the Congress at the Congress registration desk where they will receive a Congress badge, and subsequently register at the GA registration office, where they will receive a GA badge, or o register at the Congress registration desk for GA only, where they will receive a GA ONLY badge, and subsequently register at the GA registration office. • Only representatives are eligible to collect GA documents and badges (one per AsM/ RgM). • A letter from the AsMs/RgMs office, naming nominated representative, must be produced at the GA registration office as proof of eligibility to represent that AsM/RgM. If requested, the delegate and the advisers must prove identification (e. g. passport). • HnMs will receive the GA badges. 

• Guests are required to register for the Congress at the Congress registration desk to obtain the Congress Badge, and subsequently at the GA registration office to obtain their GA badge.
section_name: Ordinary Member Registration

section_content: • Should digital voting not be implemented, a roll call will take place before the first vote at each GA session. The SG will document the roll call with the help of the list of registered OdMs used at the GA registration desk. • When using digital voting, the time-frame to place a vote will be announced prior to each individual vote. All OdM delegates, including in-person attendees, will cast one ballot per individual vote via a personal device (laptop, mobile phone) using the email address registered for the GA for that OdM. Members should be informed that, should an inperson attending member delegate not be able to cast a vote due to lack of personal device, they should inform the SG as soon as possible to arrange an alternative device. • When using voting slips, numbers and colours are to vary for each vote and category, respectively areas of responsibility of Council Members.
section_name: Voting

section_name: 3.

section_content: The SG is to coordinate with the donor for joint presentation abd inform the presenting Council Member. 2. 

(Doležal) SG to request Austrian Society to indicate the amount of grant funds available nine months prior to Congress.

section_content: (Best Posters & CATCON) It is preferable for these sessions to be completed at least one and half days before the day of the Closing Ceremony so that authors can be informed, on-site publicity can be issued, and certificates can be prepared.
section_name: 3.