SBL VR cracks the Nuke-CARA pipeline with Jaunt VR in the making of “INVISIBLE” Series

SBL is immensely proud and honored at having been part of “Invisible” – a scripted supernatural drama series in VR and the first major use of this technology – we are thrilled that the widely acclaimed series is now drawing acclaims from experts and audience alike.

We undertook the post processing part of synchronization, stitching together, & finishing and provided the output to the production house and the results are there for all to see. Undoubtedly a lot of credit would go to our immensely talented and imaginative team but we were supported to a great extent by the fabulous CARA pipeline which really set the output quality up quite a few notches. Our impressive production facility and the Technological & Software support that we enjoy, has helped in becoming experts in creating realistic and immersive simulation of a three-dimensional environment, created using interactive software and hardware.

Having worked with different variations of camera rig, we understand what it needs to generate the kind of output you have in mind and which is cost effective. We come across many individual rigs varying in number and length and were required to sync them together for a smooth work flow. Initially we tried Autopane and experienced flexibility challenges. The point for tweaking and placement of the rig texture for additional cameras was the key problematic area with not much Prep control – so we tried it with Nuke-CARA which gave us control and user-friendly edit options to get the desired stitched quality and work stability for the paint/prep tasks to be implemented.

Groups of high end render farms made our process much stable to execute and save on production time. Burning of midnight oil was a regular feature through the project, but all the dedication, hard work and tenacity of the team paid off when the desired high standards of quality in output were delivered.

This is just the beginning and we look to much bigger achievements but as Virtual Reality goes, the sky is the limit and SBL VR is carving its niche in this rapidly developing space.

Watch “Invisible” episodes online on

GIS 3D feature extraction and modelling for railways using LIDAR technology

With the global drive towards Building Information Modelling (BIM) compliance gathering pace, we have seen an increased requirement for highly accurate and detailed geospatial data within utilities and engineering projects. This has resulted in a corresponding increase in the application of LIDAR technology within these sectors.

In particular, railways have a wide range of complex and critical assets that extend across the rail network. LiDAR survey point cloud data and feature extraction has become an accurate and effective means of modelling, sharing, managing and storing large asset information databases of this sort.

The primary benefit of LIDAR technology lies in its ability to capture assets in 3D. For rail networks, train mounted LIDAR equipment is on the increase because it allows accurate, dense point clouds to be acquired along with the RGB images from the in-cabin video. Having worked on a number of such high-profile projects, SBL has built up a large team of LIDAR modellers and analysts who can process and extract the full range of railway features and assets.

Fig 1 A wire frame model of a sample gantry derived from LIDAR point clouds

Railway assets include electrical network and equipment, telecommunication network and equipment, tracks and related features, signal systems and station assets. The advantage of deriving 3 dimensional data from LIDAR point clouds is that it will be accurate to a millimetre level. All the peripheral equipment can be modelled in a 3D environment as well. Along the tunnel sections of the network LiDAR is the only technology that can provide comprehensive, highly accurate information on assets.

Fig 2 station and its component assets as captured from LIDAR point clouds

Mapping to high detail and then rendering in various model platforms is the key to usage of LIDAR based capturing of railway assets. All features within the corridor width of the tracks can be captured to the same very high detail. Stations have innumerable assets components but all these components can be captured effectively using LIDAR point clouds. The creation of a real world situation using 3D models has attracted the attention and approval of many of SBL’s stakeholders and partners. Our LIDAR analysts have achieved these impressive results through 3D wire frame and surface modelling. These models were created and delivered in global GIS formats such as .dgn or .dwg or gml.

Fig.3 A tunnel section captured from point clouds

This kind of LIDAR technology based railway mapping will benefit different disciplines in different ways. This database will act a pre indicator for drivers and is of great help in their training. For construction engineers it is a monitoring mechanism. For design engineers it the only information provide kinematics of the entire system. For maintenance and operation teams it is a database where they can pinpoint hot spots where repairs are required allowing ground staff to be sent directly to those locations. Using this database a virtual railway stations and tracks can be created for various applications. Overall asset and facilities management will be greatly improved with such a 3-dimensional database.

How to become a good vfx artist?

vfx artist
The quint essential VFX professional is a talented artist who works magic on screen shots with his artistry, software/industry knowledge, discipline and a perfectionist to the core. Organization that you work for, the specific project(s) and the supervisor are also important factors that also have a profound influence.

Visual effects deals with visuals, so a keen and observant eye is a basic requirement. Study paintings, photographs and movies. Take photographs. Shoot video. See how composition works. Observe the effect of light and color and its effect on the the mood and provides the sense of dimension. It is unique how editing and timing present a story. Study the look of reality. Study silent movies to see how the visual language works. See how a single photograph can tell a story. If you’re a roto artists this may seem a bit much but there’s still an art to seeing even with rotoscoping. Which is the complex frame? Are the shapes moving smoothly? What areas should be grouped and segmented?

Where should the points be placed? And if you shift into other areas of visual effects all of this will be of value to you. Artistic principles like follow through for an animator – providing weight and character, colour adjustments, light wrap around objects – 2D &3D. For a lighter it could be light ratios, how to set mood and dramatic effect with lighting.

A compositor should be an expert on linear color space and what “premult” and “unmult” do. A lighter needs to be familiar with different types of CG lights and how different basic shaders work and look. These fundamentals will be of value whichever software is used and will allow you to get the most out of your software package. They will also help you problem solve. These days there are a lot of complex software tools. Most artists learn and use multiple software tools over time.

Visual effects time is precious. Saving time and avoiding wasting time can mean more profits and joy !! Obviously we can’t control things outside our control but the artist is an important cog in doing it as efficiently as possible. Avoiding common errors is a big time saver and allows you to focus on the true needs of the shot. In visual effects, time is frequently worth even more than money; it’s worth time. Given limited schedules and hard deadlines it’s the thing you can’t get back and it’s very difficult to make up for any loss. In visual effects, time is frequently worth even more than money; it’s worth time. Given limited schedules and hard deadlines it’s the thing you can’t get back and it’s very difficult to make up for any loss. In visual effects, time is frequently worth even more than money; it’s worth time. Given limited schedules and hard deadlines it’s the thing you can’t get back and it’s very difficult to make up for any loss. Speed would come automatically if you know your tools well enough, explore the various options available on the softwares and are open to experiment and get the quickest way. Finishing shots is a balancing act of time and quality.

Essential basics that might be true for other industries or professional life in general are always prime requisites, a few are listed below :

❖Be punctual and organized – Discipline is of utmost importance
❖Taking Notes in meetings and daily huddles so even bare essentials are not missed out.
❖Daily pointers for work done and scheduled ahead so the supervisor/client is updated on progress.
❖Shot changes – As requested, Changing a shot parameter so minutely that it’s impossible to see without a split screen is always a waste of time unless specifically requested.
❖Ask questions. Do not guess. Plan well.
❖Keep a checklist for ready reference.
❖Never compromise on quality – output should always reflect your best effort.
❖Always double check as we do in exams, there should be no scope left for errors.
❖Workflow management – knowing about hierarchy, procedure, organizational goals and mission, availability of internal tools/solutions.
❖Learning & Development – It is also very beneficial to keep honing your skills through practice, learning, training , discussions, attending meets and seminars, talking to other professionals and seniors
❖Be proud that you are part of the VFX family and derive satisfaction in your job.

Much of what a visual effects artist does involves problem solving of artistic or technical issues. Once we grasp the Technical and artistic fundamentals and know your tools you should be able to resolve many issues on your shots. You should be somewhat self-sufficient. However, if there is a problem that doesn’t seem to be easily solved in that case take the assistance of a specialist or supervisor. Don’t spend time trying to fix something which needed only additional input from someplace else or that might need a different shill set.

Before submitting the shot to your client, supervisor or passing an element on take a moment to play it back and review it. Are you using the correct versions and takes? Do we have the parameters and elements in sync? If you’re doing match moving and missed something many people might work on it for weeks before the critical element is detected due to which the animation may have lost a lot of time and have to redo their work simply because you didn’t take the time to do a check of your own work.Does it match the information that you are working on? Are the count sheets and the elements matching in length and size? If you were supposed to say work on a Roto element and its not present, then it has to be flagged across to production. By flagging it as missing production, you can work on the issue and decide what further steps need to be taken. You may find it was already done and just hadn’t been copied to the directory yet. Avoid losing time. Build the shot in a logical and structured way. Don’t forego that later by rushing in a lot of patches and work around.

Self Assessment & Review – It’s easy to get so focused on the details that you don’t take a moment to review and check if its fine. Does it look right? Are the basics of the shot working? Are all the shadows consistent in density, angles and color? Is your focus completely on getting the matte edges of the leaves working correctly that you might have missed on the alignment of crucial elements ? Have you focused on a small secondary action when the creature should already have moved across the room? Make sure you don’t overlook the obvious.

Do not simply keep tossing in smoky and dusty elements or putting in more key frames if that’s going to make it more of a muddled mess.. You would have to rebuild part of the shot or replace the nonconforming elements that may be working at cross-purposes. Don’t add a graded node that could darken the shot and then repeat that with a node that brightens the shot. The forest might not be visible through the trees. Usually a second ‘eye’ is what is needed. What’s working about the shot? What’s not working?

Shot in context – It’s essential to understand how the shot you’re working on fits in the sequence. It’s mandatory to have a look at how the full shot pans out, both creatively and technically. There may be an issue or it might be another chance that has to be rectified. One can leverage off of what’s already been learned for the sequence and put to use in future too.

Keeping it simple & taking changes in stride is a requirement in visual effects and has been before digital existed. No awards for having the most key frames or the most layers. Given the visual complexity of shots keeping it simple isn’t simple however making it more difficult and complex can be avoided. There may be technical issues that require a different pipeline structure or software to be used. The VFX company may require shuffling your desk to somewhere else. You have to be able to roll with these changes. If any and every change is going to make you angry then vfx is not for you. Flexibility is the operative word.

VFX is also all about teamwork. A lot of talented artists can be found working alone in their corner over long hours but they are also part of the larger team doing different aspects towards the end goal. You may be working on just one part of a shot whereas other specialists would be taking care of other core processes which might require a different skill set. You may be getting prep work from someone and then passing the buck to another person as the progression to the final shot happens. All of this interaction means you have to work and play in coordination with others. The work itself is tough, without someone in the process making it more difficult for everyone. Be a team player and not someone others avoid to be paired up with. Artists should be somewhat self-sufficient (and still team members). The amount of freedom and how far it takes you depends on the team, supervisor, project and sometimes the end client.

If you see the need to add a smoke element or put in a secondary animation move that will make the shot better. On the other hand you shouldn’t take the shot through completion without having a dailies review. More than likely a work in progress has to be reviewed by the supervisor and director. It’s usually very helpful for the director to cut in a work in progress. There’s little point in polishing and finishing the shot if the director discovers it’s not working in the sequence for some reason or requires a major change.

On the shot being first turned over we can voice our concern about the difficulty but not harping about it on every review instead useful solutions towards making it easier will be appreciated by all. The elements are what they are at that point. Usually the live action plates are the best that could be shot under adverse circumstances and blame game is never of any help. Now if you actually need help or feel the difficulty is beyond your current abilities then simply state that to your lead or supervisor. Flailing away at the shot without knowing how to do it doesn’t help you or the production. “Fake it till you make it’ is a not phrase you want to use in visual effects.

Communication is an imperative facet to avoid waste. We have to be able to be clear and straightforward with unprecedented issues or obstacles. Make sure to prep so you can show your supervisor the problem concisely and fast. Sometimes one we might have to run a example set or to capture a still picture. Since we’re dealing with visuals all of these help the communication method which enables you to do the sketches in a much better manner.

Loads of patience is required as many steps in VFX take time and focus. Time to set keyframes. Time to roto. Time to render. Time for feedback. You want to work efficiently and try to work on something else if you are waiting for a render. But in the end you need to have patience to do detailed work which is time consuming and at a lot of times you just have to sit and wait. If you’re an impatient person then visual effects may not be right for you.

Never blame your tools (or elements) – There’s an old adage which says – “It’s always a poor worker who blames his tools.” In this modern times it’s certainly possible there is a software bug or other issue that causes a problem. It might be forgotten that a blur filter had been added at one point and to blame the original element for being soft or to not render the right frames with the right settings. It can be difficult to admit that it was a mistake but identifying the actual problem will certainly help to resolve and to avoid in the future the better. This relates to the double check and problem solving points.

Sense of humor & Fun factors -Since VFX invariably involves pressure, tension and hard work, sense of humor is a must have. On occasions the absurdity of a situation could be overwhelming if you don’t have the ability to shake your head and enjoy a hearty laugh then the entire atmosphere will become a burden and uncomfortable. Take a break by just walking away from your desk, talking inconsequential things or exercise and yoga.

What you know about Stereo Rotoscopy?

stereo rotoscope
The areas of live action frames are traced by Roto artists where computer graphics will overlap or interact with live images. Mattes (clear areas) are created inside the frame in order to allow all elements of the scene to be layered convincingly. This helps the Compositors in combining all the various elements accurately.

The most complex shape that the subject is in can be found, to outline that first, to understand the maximum points required to be rotoscoped. Rotoscoping tools used in the compositing software have advanced and deep deviation or curvature that can be controlled to make detailed curved lines with least number of points – image segmentation, creation of mattes or masks, More often than not using rotoscoping. The essential surfaces should be isolated individually. The level of detail depends on the required conversion quality and budget.

In Rotoscopy one can trace an object using a set of tools within the compositing software for making a new alpha channel to a specific part of an image sequence or video. They can manually create this alpha through copying the tracing on top of elements inside the video and create different shapes around the object and provides animation to those shapes to sync with the movement on all the frames. The system automatically interpolates between keyframes to usually provide required result/output without having to create a new frame every time.

This is one of the steps in processing 2D to 3D Conversion movies (the process of transforming 2D film to 3D form). Once mattes/mask have been created through rotoscope it will move to next process called Depth map. It is only through this Depth map that the conversion of 3D form from 2D can be effected.

The use of blue and green screens can make the process of compositing varied elements inside a scene much more simple, (however not every shot can take advantage of blue or green screens) so rotoscoping even now plays a significant role in the entire process of visual effects.This can be a time consuming process, but the results of rotoscoping can be excellent. If more time and effort go into a roto job, the finer the results can be. It is really a very rewarding process! Every movie, TV show or music video that has special effects will require rotoscopy to enhance the picture quality and hence the Roto artists are and will remain an integral part in the VFX pipeline.

NUKE, Mocha, Fusion, Silhouette & AfterEffects are some of the software widely used in rotoscopy for best quality and ease in delivery of output.

iOS 10 – State-of-art Amplified value addition and superior feature specifications

Smartphone with cloud of application icons

iOS 10, the next-generation operating system for iPhone and iPad is on the way. Apple has already released iOS 10  beta 4 version for all users and beta 5 version for developers only.

iOS 10 offers a deep learning curve for developers and a better user interface for iOS lovers. There are plenty of exciting features to be explored. The final launch is expected to be on September 2016.

Fortified iMessage for developers

It’s the largest enhancement apple has ever made. Developers can play with the latest iMessage app to edit photos online, do payments etc. Live interactive long lasting messages in a shared group and messages that would be live with an expiry date set for them.

iMessage API  supports all these features as a further extension by APPLE. Provided the recipient is uninstalled with the iMessage application, there would be a link available for the delivered messages.

Another impressive attraction is that the new Xcode 8 simulator which has a developer mode to let you see both sides of the conversation . Debugging becomes much more simpler this way.

An important issue developers face is that their debuggers sometimes fail to identify errors. Simplified by making your breakpoints working. This can be done as below :
go to “debug attach” -> “process” -> ”message extensions”.

APPLE also provides support to custom messages along with message extensions encrypted within.

Stunning life-like Animations

iOS 10 brings out more lively & fine tuned animation effects, for superlative user experience unlike previous versions where it was cumbersome to create high quality animations. Now the developers have more flexibility and control over the animations and GIFs.
The key class to handle animation is UIViewPropertyAnimator ,  which gives the option to create reusable animations.

Recreate speech to text

iOS 10 introduces a new API that supports speech recognition. Speech recognizer lets you to build apps that can recognize speech and transcribe it into text. The application acts according to the text that has been converted from speech.

The three important process are :

  • The entire complex process is managed and regulated by SFSpeechRecognizer
  • SFSpeechURLRecognitionRequest  allows you to request transcription of recorded audio file.
  • The result, which includeS transcribed text, callbacks etc. is given back via SFTranscription

New and advanced notification features

Apple had introduced much improved notification support which we can deliver. Even though there is a deep learning curve, developers are capable of handling various aspects of notifications including creating notification message, triggering notification, user authentication etc. There is no UILocalNotifications any longer.

“HeySiri” and much more with SiriKit

Siri is opened to third party developers !!! Another remarkable breakthrough, from iOS 10 onwards is that the user can control third party apps (non Apple apps)  via voice. SiriKit enables your iOS 10 apps to work with Siri.

Calls, messages, payments, photos, workouts, and booking rides can now directly work on Siri support. Siri will be responsible for all kind of voice recognition and parsing.

Siri kit implementation requires the user to register with siri. Domain specific registration is required. Those who register for a particular app is provided with an object that represent user’s intention. It’s then up to the user to initiate domain specific actions and provide a response back to the system.

Live Replay Kit by APPLE

Replaykit was introduced in iOS 9 which allowed users to record, share and play audio files. They can use it along with app or games.

iOS 10 takes the whole process a step further by introducing live broadcasting of ReplayKit
streams, and does so by building on existing live streaming services: users install apps that support live streaming, and ReplayKit  lets you hook into them.

Improvements via Xcode8 supporting iOS 10

  • Ability to use swift 2.3 and 3.0 at the same time.
  • Keep your swift 2.3 code and migrate to 3.0 when you are ready.
  • More easier device preview. Device and orientation layout are visible beneath the layouts.
  • Ability to test over splitview for ipads and slide over controls.
  • Apple also added the ability to specify color and image literals, which certainly make coding a little easier.
  • Xcode brings out a code completion popup which provide an option to replace color literals with a graphical color literal from a list of color selections. This is mainly for swift color literals.
  • Working with image literals is quite easy now. Images assigned as variables are able to view as a thumbnails within the code part itself which is quite strange.But the developer can make sure it’s working on compile time itself.
  • Developers can edit the storyboard when zoomed out. This was impossible in previous versions.
  • Xcode brings out a new Debug Memory Graph option which is much useful. You can simply activate this by enabling a new button in between Debug View Hierarchy and Simulate Location in Xcode’s debug area.

Picture perfect photos and images with computer vision

Apple revamps photo gallery to a next higher level which supports clustering of photos into trips, people and topics. It also introduced a magazine style to photo albums.

iOS 10 enables photos and videos to be captured in a specific memory and add special mood effects to the movie created.

Apple maps – a whole new horizon for precise Navigation

  • iOS 10 fixes the maps inability to scroll ahead of the route. Goodbye to the annoying spring back to the current location whenever you try to look anywhere else.
  • Apple through iOS 10  is also updating its map feature. Now you are able to pan and zoom around the map, zoom in and out of long stretches and complex interchanges.
  • iOS 10 is competing with Google maps by adding traffic on route with more points along the route chosen. It’s trying to expand the existing functionality.
  • Vehicles that supports Apple CarPlay not only get suggested alternate routes based on traffic conditions, Maps turn-by-turn directions can pop up on the instrument (if they have a screen next to the odometer).
  • Apple is weaving iOS 10 information from other apps into Maps, like if it knows you go to
    work at a certain time, it’ll make a suggestion for the route, or make one based on a calendar
    event address.
  • That’s just the start. It’s also opening up Maps to third-party developers, so Uber riders can
    call, follow and pay for their ride without ever leaving Apple’s app. It’s getting there….

e-Legislature an e-Governance Solution for improving Legislative processes

The e-Legislature system – a secure end-to-end governance solution developed by SBL, will fully automate the day to day functioning of the entire legislative assembly and will radically change how the legislature process works in India in the near future.

The Assembly Session proceedings will be completely paperless and introducing Bills and laying various reports and answers to questions inside the House will be handled through touch-screen based computer systems deployed for each legislative member inside the House.With e-Legislature system, the members inside the House will be able to exercise their voting over motions electronically. Similarly, the information provided for media persons too will be digitized and a media room with computers using the e-Legislature system will be available for the use of media persons. The e-Legislature system will use Digital Signature Certificates (DSC) for user authentication; henceforth only digitally signed documents converted into PDF/A standards would be allowed to be uploaded on the online system. This will ensure error free,
paperless communications within the legislative house.

e-Legislature’s Secretariat interface will manage the Questions Processing System by accepting the questions from Members, issuing notices to Departments, accepting replies from departments, approving the answers and fixing the dates by the Secretariat and finally creating List of Business for a day during the Assembly session.

The e-Legislature system increases ‘People Participation’ in the Legislation process by automating the process of Assembly Bills MIS and allowing to seek People Suggestions on Bills online through a secure web interface. The system also ensures that the proceedings inside the House will be instantly available for the public at the end of day of every session by digitizing and publishing of Verbatim Record of House/Committee Proceedings.

Legislative, Automation of internal working of Legislature Committees Publishing of Budget, Gaining Control over Budget and Scrutiny Over Government Finances by Legislative Assembly, obtaining Press and Media Information System, Generation of Identity Cards/Passes, Publishing Bulletins, Working with HR/Accounts for MIS
(Members/Employees), Procurement of Stock Inventory and the Dispatch of diary and Library Information System.

e-Legislature system utilizes the latest technologies of SMS and Email gateways to alert the users regarding work at hand.
e-Legislature system for MLAs would include an enhanced Constituency Management System including Submitting Priority List of Works under MLALAD Fund, Monitoring various Works running in the Constituency, Redressing of Public Grievances/Demands, Management of Employee’s Requests (Transfers etc.), Party Information System, and preparing Tours / Appointments /Meetings. , Online Submission of Questions & Property Returns by MLAs, Online Annual / Supplementary Budget Books etc.

Under this system, the citizens and employees will be able to submit their grievances, demands and requests to MLAs online. Online submission of suggestions on bills and for entry passes during sessions will also be managed through this new portal. It is worth noting that significant administrative costs for running the house have been saved by implementing the e-Legislature system.

Following are the major e-Legislature modules :

Member and assembly management
Assembly house proceeding management
Touch screen based member console
Questions and notice processing management
Constituency management
Bills processing
Committee management
Grants and budget management
Video archival management
Accounts and establishment management
Public information system
Library MIS
Physical security management and access control
Inventory management
GIS based data management
Document digitization and archival

Based on the track record in implementing similar projects in government and public sectors,NICSI selected SBL as Associate Partner for the development and implementation of similar e-governance Solutions at HIMACHAL VIDHAN SABHA Himachal Pradesh Government recognized SBL’s work through the highest civilian award for e-Governance

Benefits :

  • Reduces usage of paper in an assembly by 80% and saves approximately 15 crores annuly (Ref:Himachal assembly)
  • Improve efficiency by eliminating redundant processes and increase data processing by 30%
  • Improves decision making with online reports and files which marks 90% improvement over physical file movement
  • Improves public awareness and participation on legislative process
  • Improve control and monitoring on day to day working of assembly
  • Increase security by adhering to more robust security practicalities
  • Better information at right time enables the stakeholders to correct decisions with 0% downtime



Management of road networks and its associated assets is a huge task for all transportation agencies around the world. The traditional ways of collection of data was time consuming and the productivity of the staff was at the best average. With the advent of new technologies like Mobile LiDAR Mapping, the collection, assimilation, analysis, design, construct, maintain and storage of data has become very fast, accurate and cost sensitive This dynamic system of mensuration can be used to acquire highly accurate and compact 3D statistics by safely driving a gathering vehicle at public road speeds

Mobile Lidar systems is made up of of four different devices: a laser, a scanner, a photodetector and a GPS/IMU positioning system. These four systems assimilate to measure the distance to an object by lighting the target with throbs of light from the laser instrument and gauging the time it takes for each throb to bounce back to the sensor. For the reason that light moves at a persistent and known speed, the distance between the laser instrument and an entity can be measured with a high degree of accuracy. A briskly firing laser can cover entire scenes in a few strokes, visualizing the topography and extracting data. A highly capable processing software then transforms raw data into colorful 3-D point clouds, and the end results are multifaceted, high-resolution maps.

Collection of detailed, high accuracy street-level data of street framework is expedited by having instruments capable of reading GPS/IMU on a automobile platform, achieving immense extents of GIS-friendly LiDAR point cloud data in short amount of time. Terrestrial LiDAR system is competent to see data flanked by buildings and under tree canopy, which airborne systems, will never be able to capture. Mobile mapping systems usually collect a full 360-degree FOV at a speed of 30-40 kilometers per hour. The data collected will be highly precise and can be used to generate convincing 3D data and highly accurate road maps.


Geo-referencing factor of mobile mapping is akin in idea to airborne platforms, but distinctive in run through. It is not possible to keep the GPS lock all the way through an entire mobile survey. The mobile platform must be able to traverse, and accurately map, below tree canopy, under bridges, without loss of positional accuracy. The IMU system become judgmentally important. The airborne system necessities for GPS/IMU quality basically do not apply in these situations.

As is the case with every mapping application, supplementary imagery and substantial data post-processing is often crucial to producing GIS or CAD-compatible final products. The processing applications necessitate solid surfaces with unambiguously defined edges, and topologically-structured feature objects (points, lines, and polygons) with widespread data description and attribution. The time and effort involved in taking out these features from LiDAR point clouds has been a process only knowledgeable persons can work out. This needs special LiDAR/Point cloud processing software and custom data formats, as is for airborne or fixed systems, transfers over to mobile systems and is augmented by the steep quantity and intricacy of the data acquired.

Incorporation of mobile mapping data, generating exhaustive data for highways and metropolitan infrastructure) with mobile topographic LiDAR survey generated terrain models and oblique imagery is sure to turn into the gold standard for street mapping and visualization in the very near future.

Automatic Acquisition of 3D City Model

3D city

Urban areas are bestowed with a variety of geo information. Some of this spatial information is virtual and some are very complex physical information. Virtual information includes administrative boundaries such as municipal boundary, electoral ward boundary, jurisdiction boundaries of various departments etc. Physical information includes transportation network, communication network, utility network, land use land cover features, hydrographic network etc. Any kind of city management needs a data base containing the spatial information. All queries related to a city or urban management system will definitely relate to some location or spatial reference. Though two dimensional maps are available for the purpose, 3D city viewing is rapidly gaining acceptance and application over the former in most of the smart city initiatives. Application of 3D city models ranging from sitting of tower locations of cell phone companies to micro climate, environmental, air pollution, architectural designs and urban heat wave analysis.

3D city models are digital three dimensional models of urban areas with all its features. These features include aforesaid virtual features as well as other physical furnishings such as buildings, land marks, vegetation, infrastructure landscapes and terrain. These features can be represented in spatial data base in the form of two dimensional as well as three dimensional features class. 3D city models are visually integrating various geo spatial elements to real world scenarios with all its complexities. Creation of automatic 3D city models involves preparation of data base based on the required level of details, storage of the same in a data base, construction and detailing of city models and visualization of the same through various application platforms.

Application of 3D city models

There is a verity of application for 3D city models. Unlike last decade where 2D data base were in focus, current decade witness 3D data base model applications in many developmental activities. Some of the key applications of 3D city models are listed below.

Master planning applications: 3D city models are an apt tool for the town planners. 3D city models will help planners from conceptual development stage to the completion and long term environmental impact assessment stage. The benefit of 3D city models in two planning is that it will reduce planning errors and hence monitory loss, it provides better visualization capabilities and hence monitoring is very easy. The most import part played by 3D city models in such application is that it will greatly reduced project delays. It can also add value as a depicter which can monitor illegal vertical growth of the city.

Spatial Database Infrastructure Applications: 3D city models are part of the spatial data base infrastructure of the region. Irrespective of the initial cost of preparing such data base, in the long term it will be the robust data base service in the back ground of all developmental activities. This will be a base data for further spatial data simulation and modeling. Site suitability analysis of roof top for solar panel installations, thermal emission analysis of buildings and urban fabric are some of such analysis.

Disaster Management applications: 3D city models are highly helpful in disaster management in terms of providing near realistic effected of the disaster. It can simulate fire, flood, bomb explosions etc and after effects on the same in urban infrastructure in place to a great precision. Such simulations will help administrators and planners in managing their rescue operations and resource mobilization.

Navigational applications: 3D building models and terrains will give a realistic display of the area for people navigating and crossing through the area. It is gaining widespread acceptance than simply looking at the locations. It can be act as a tool for intelligent transportation system.

Utility design applications: 3D city models will play a key role in designs of sewerage channels, railway line routing, highway routing, power transmission lines routing and other geo designs.

Archaeological applications: Historical buildings and cultural heritages can be modeled to a highest level of detail (LoD5) in 3D city models so that its intricacies will be preserved and will help in maintenance and repairing.

Decision support system applications: 3D city models can be aptly used by planners and managers to take informative decisions using interactive models.

Property management applications: 3D city models can be effectively used for property management and also for dispute settling tool.

Entertainment applications: 3D city models can be back ground and give virtual reality for gaming industry.

Preparation of 3D city model data

There are several kind of input used for preparation of 3D city models. These are ranging from very high resolution stereo aerial photographs to high precision lidar data to high resolution satellite images. The kind of input used and level of details (LoD) extracted are solely based on the requirement of 3D city model. Buildings are most important items in a 3D city Model. The LoD is mainly for the detailing of the buildings. There are five levels of standard LoDs and these are

  • LOD 0: 2.5D footprints
  • LOD 1: Buildings represented by extruded foot prints
  • LOD 2: Extruded foot prints with standard roof structures
  • LOD 3: Detailed building architectural design models
  • LOD 4: Architectural design models with interior designs

Type of data in 3D city Models

3D city models have much kind of data. These include but not limited to GIS data, CAD data, BIM data, and some of the non spatial data as attributes. GIS data is very much required for any 3D city model. Base maps, digital elevation models, digital terrain models, land use maps, and administrative boundary maps, road network data etc. are the GIS component of the 3D city model. CAD data play a key role in 3D city models. Most of the buildings with required level of details as mentioned above can be designed in a CAD environment. Other infrastructure such as railway network, road network and other utilities can be modeled in CAD environment. The outcome in the form of wire frames or surface models will add flavor to the 3d city models. BIM data will provide with one step ahead information of CAD data. The specifications of the buildings in the form of attributes can also be incorporated in CityGML data model.

Data Management

3D city models comprise a variety of data sets, in a variety of formats. So there cannot be a uniform data base schema for the same. The data base schema will be depending on the requirement and application of the models. The component GIS data sets can be raster rata sets as well as vector data sets. 2D raster data sets can be in .geotiff, .img, .jpg like format based on the rendering capacity of the hardware as well as software and internet capability. 3D models again in ASCII, tiff or obj format where common CAD, GIS and graphic software can render and display. Reliable data base management is a prerequisite for complex analysis and result derivation from 3D city models. So a relational data base is very much required for running and utilizing any 3D city models. In this relational 3D city models, hierarchically structured, multi scale data can be stored, retrieved and analyzed. For Updation of the 3D city model data based is also possible only through a relational data base. Also the relational data base should able to hold multiple formats of the data and its rendering. Open geospatial consortium standards and norms can be followed in 3D city models creations as well. Such data bases are referred as city GML

Visualization of 3D city models

One of the major challenges in automatic acquisition of 3D city models is its visualization and semantic rendering. Visualization is a challenge because component of a 3D city model will be mostly from different data sources such as geo data, GIS data, BIM, CAD etc. So a common frame work schema based on the requirement of the model need to be established beforehand through a relational data base. Visualization and rendering are based on the core functionality required through interactive application suites. Typically 3D city model rendering should be fast, scalable, and cost effective. In case of 3D geometry and 3D texture display a specialized algorithms need to be established. In general rendering can be service based or maps based. City GML will provide not only the visual 3D city models but attributes can also be viewed.

Service based rendering: This kind of rendering will based on data base architectures which runs on client applications which is external in nature. In this case all 3D portrayals of computer graphics and other GIS data sets will be the responsibility of the external application. This can be Open Geospatial Consortium (OGC) compatible. Services based rendering can be of Web 3D service or Web View Service. The former will be based on the client application which is converted the scene graphics and other geo data in 3D models and later is through server based services. In this case the server will generate 3D views which are uploaded on requested to screen and streamed based on the scale of rendering. Here client applications will generate 3D models and save in the server and rendering is not directly done by application.

Map based rendering: Smart 3D city models are following map based approach and render 3D visualization to any kind of platforms. In this case the 3D city model is arranged to a series of small tiles which enable automatic 3D rendering. Different levels of details of the model and pre arranged in a server which any number of concurrent clients can access. Map based rendering is more simplified in terms of data transfer and complexity of the 3D data models.

Building Information Models (BIM)

Buildings are the major and complex component of any of the city model data base. Building information model can be from simplest extruding footprints (LoD1) to very complicated architecture with interior designs (LoD5). Automatic extraction of buildings is possible from 3d laser point clouds and photogrammetric approaches. But through this kind of approaches only LoD1 and LoD2 is possible. For higher levels of details Digital terrain models and digital surface models are required. Operator interference and statistical approaches are required for higher level of details of the BIM.