Point clouds live somewhere in space, where they are in space are based on something called a coordinate system. In today’s post, we will keep the math to a minimum and approach coordinate systems from a practical, applied approach. In the world of CAD and point clouds, coordinate systems are defined by an X, Y, Z origin point, and a Z-axis rotation. When a point cloud is first registered, the origin and rotation are based on where the first scan was taken. This is seldom a good location as it is very arbitrary. To produce a useable point cloud, we need to put the point cloud on a rational coordinate system that the whole project team can use.
We assume that your building is relatively flat and level. If it is not, we need to talk. When we say relatively we mean that the main floors of the building would be flat within +/-1″ at any measured point.
How do you know what coordinate system to use? That is easy; PMC will ask a couple of questions to understand better what coordinate system is required for your project once scanning is complete. We do our best to break it down into a few simple questions.
Before we begin
Typically buildings will have some drawings or plans originating from construction. When there is existing CAD/BIM data of the building, it can be used as a reference for the point cloud data’s alignment. Generally, this is the preferred option for most teams. Aligning to your existing CAD/BIM data ensures that the existing data can be used without a need to shift it in the CAD/BIM environment.
If your building is ancient and there are no existing CAD/BIM drawings, no need to worry. We can work with that.
While AutoCAD and Microstation straightforwardly handle coordinates, Revit can have a Shared Coordinate added. If your Revit model is using Shared Coordinates, please let us know.
Have a survey file you want us to use? We should have already talked about that, oops. Please stop here and contact us.
It starts with a question
The first question you will be asked is, can you provide a CAD (DWG/DGN) or Revit model of the scope area? If you answer this yes, you will be almost done. We will have one more question for you. No worries though, even if you answer no, there are just a few more questions.
PDFs can not be used for alignment, only CAD/BIM data. If you don’t have a file, it’s not a problem. There are just a few more questions we’ll need to ask.
A simple Yes or No
If you chose yes to the first question, keep reading. If you chose no, skip to the next section.
You’ll be asked, do you want PMC to perform the best fit of the point cloud to the provided CAD or BIM file? What does that mean? It means that PMC will align your point cloud to the provided CAD or BIM file. Given the difference between the actual built environment and the assumed world of CAD, your point cloud will be centered within the CAD data and not aligned to any one benchmark. If you want to lock the point cloud to one specific point in the building, you need to pick no to this question. Some examples of this desire to have the origin be the center of a building column or a building corner.
You chose NO, now what?
You will be asked two additional questions to help define the origin and rotation of the point cloud. We’ll start by asking about the X/Y location then rotation. We provide the most common answers for you to pick from, but you can always choose to customize it. We know that every project of the built world is unique and will often require unique solutions.
Q: For the X and Y-axis origin (North and Easting), how do you want the point cloud aligned?
A: Here, we ask you what point within the point cloud do you want X=0 and Y=0 to be. Typically this is some logical point in the building, like a corner. Sometimes it can be a known benchmark point like the center of a fire hydrant.
Q: For rotation of the point cloud, please select what you would like.
A: In the first question, we locked in a 0,0 point, but we can rotate around that point. You likely don’t want your building to be rotated at 31.25 degrees, but what do you want it rotated too? The most common answer is to align the longest wall along the X-axis. You should consider how your project will fit your sheets and if having a project north or true north is important to you.
The Z-axis or Elevation?
We’re almost done here. We need to sort out elevation. What we need to know is, what do you want the elevation of the first floor you walk on when entering the front door to be? The most common answers are 0 and +100. Sometimes we are asked for sea level. We will take multiple measurements across that floor and average them to set the elevation.
If your building has multiple “main doors” to different floors or you think we may be confused by what the “front door” is, please reach out to us.
Wrapping it up
You’re done! We know how to align your data and it will be in your hands shortly! Have concerns still? Worried we don’t know what you mean? No problem, the form is not meant to replace talking to one of us. If you have any concerns at all we are here to help. Please feel free to reach out at any time to the team at PMC.
Enterprise Facility Integration (EFI) is a method my teammates and I at PMC have developed to help client’s phase into BIM to FM maturity so that value milestones are defined. Anyone who has held positions in BIM Management or as a VDC Project Manager in the last twenty years understands that corporations adopt BIM incrementally. Adopting BIM practices strategically results in incremental returns. The PMC AEC+O team has developed our process using experience we have gained through managing Architects, Engineers and Construction (AEC) teams migration with BIM tools and data. Using our knowledge, we have created a phased approach to data maturity and a foundation for Digital Twin and Industry 4.0 use cases. These can be used by owners and operators seeking BIM to FM and Digital Factory value. Two helpful tools PMC uses as we phase value for operations and facilities management BIM use cases are the data maturity wedge (Digital Twin flavor) and BIM value hierarchy.
Building a data standard for your highest value
PMC – Data Maturity Matrix
The data maturity wedge was introduced in the UK BIM standard as a key component in a path to iBIM (collaborative interoperable data). It has seen many flavors in different standards, articles, and slide talking points. The wedge is a common expression of an organization’s building data maturity. It represents enterprise record data and all available AEC supply chains. The four levels of information exchange represent data interoperability or lack of opportunities to standardized and exchange information between stakeholders in building life-cycles.
The PMC version of the wedge considers phase four as the integration to Digital Twin and Industry 4.0. The key reason is that all levels of data should consider the highest usage goals. What this means is that when a standard is considered for example, organizing asset documents, being indexed into level four becomes a value. The same can be said for all intermediate forms of data from Revit to CMMS. The unique difference from what the PMC maturity wedge is that it’s not just a high level BIM/VDC viewpoint. The PMC wedge is a search for interoperability beyond the AEC life-cycle. Finding common data value across AEC+O eliminates the biggest problem with digital building/plant floor life-cycles. A large percentage of design and construction data becomes throw-away rather than serve operations. As each form of building or plant floor data becomes interoperable to level four, (the foundation of data usage) the value hierarchy becomes a catalyst for return on investment.
BIM Value Hierarchy
Data Value Hierarchy
PMC’s BIM Value Hierarchy looks very similar to Mazlow’s for a reason. In the same sense a person can’t self-fulfill their needs without a foundation, Digital Twin/Industry 4.0 can’t return value without a foundation. That value needs to be informed by building the foundation from the bottom using standards.
When PMC first starts partnering with a client, one of our first goals is to define the standards base on the usage needs to be fulfilled. In this case our Hierarchy focuses on a high level of value. Since usage and value are at the top of the pyramid, each collection of data, from basic to rich, needs to be interoperable and integrated. There are at least five layers of integration we feel need consideration:
Digital Twin/Industry 4.0 usage – forecasting, big data analysis, etc.
A consideration for the visual of a fully shaded in pyramid is that would represent a completion of all levels. For a large enterprise, this takes many years in the commissioning of data alone. A phased approach means finding a way to leverage return along the migration of data.
Building a foundation
PMC Early EFI Value
Interoperable data can enable so many more value propositions than just big data forecasting. This is the reason EFI is able to phase return on investment. The iBIM goal, for example, from the UK standard, is a milestone of rich data collection that comes from construction and renovation projects. Integrated design workflows in facility construction have proven “SMARTER, CHEAPER, FASTER…” for owners, Architects, and Construction managers. The same can be said for digital factory. However, those value propositions often end in throw-away record data. That might be because they lack the higher value interoperability that facilities management (FM) and operations requires. Another possibility is that without people in stakeholder positions the data goes un-managed and becomes obsolete. A well-planned early phase should milestone for these possibilities and migrate people and data to implementation.
PMC will continue to digitize everything in our path as it has done for more than twenty five years. However, over the past several years we have made it a goal to not deliver throw-away data. The way we do that is to ask about a higher longer term value of interoperability. My team and I are also seeking to partner with our clients so that our foundational digital modeling services also deliver sustainable data. Over the last two years we have looked to consult on all barriers that prevent functional teams from operating and maintaining the data we deliver. This is why we have developed partnerships and services to compliment 3D data capture services. Here are a few we provide.
Site and Building Reality capture at all scales of precision
Certified Training solutions in the cloud and on-site
Well, What is it? Terrestrial laser scanning (TLS) is a form of measuring with a tripod-based LIDAR (light detection and ranging) instrument used to capture high accuracy data of buildings and other objects.
What is it used for?
TLS is used for a large variety of different applications, including capturing the flatness of a wall, preserve the conditions of a crime scene or accident, document the faꞔade of a large building for pre-fab architectural paneling, analyzing the shape of a vessel, volumetric stockpile surveys and many more.
Leica Scanner at a Bridge
How does it work?
Terrestrial Laser Scanners works by emitting an invisible laser to measure 3D points the same as a survey total station would. The difference is the scanner’s ability to measure its entire scene and the speed at which the measurements are taken.
The laser field of view is 310 degrees vertically and 360 degrees horizontally. The laser scanner will rotate upon the tripod and spin the mirror at the same time to capture the full scene. Each scan takes about 3-7 minutes, depending on the resolution.
What Does a Terrestrial Laser Scanner measure?
Terrestrial Laser Scanners measure everything in the line-of-sight of the laser. The smallest details like the texture of brick, the leaves on trees, and the metalwork of ornate hand-railings are picked up in the scans.
Scan of a museum
What is the accuracy of the Terrestrial laser scanner? Is it any better than a pro-3D camera?
Absolutely, terrestrial laser scanners can measure points as accurate as 3mm at 30 feet. A standard pro-3D camera cannot achieve less than an inch of accuracy. The resulting “point clouds” from the scanner are extremely high-resolution with points in spaced very close together, so close that the result of a scan looks just like a photograph.
The higher the resolution the slower the scanner will rotate making the resulting point cloud more detailed. The faster the scanner rotates the less time the laser has to document to small changes creating a lighter point cloud.
The Resolution of the scanner does not always directly affect the resolution of the “project point cloud”. For example, scanning a single wall with a handful of low resolution scans the resulting point cloud will be a higher resolution because of the number of points that accumulate from more than one low res scan.
Grey-scale Factory Scan
Color or Black and White?
Depending on the need or conditions of the project, laser scanning can be conducted in absolutely no light. This makes it possible to measure and see things in places of absolute darkness. When scanning in dark conditions, the scanner is unable to pick up color unless artificial light is added, but the resulting point cloud imagery looks almost like night vision. Everything that was once very dark will be brightly visible in the 3D imaginary.
What are the benefits of using terrestrial laser scanning?
Benefits in Architecture
Capture the “as-is” conditions of a building quickly, accurately, and with little to no disruption. Photorealistic imaging and 3D visualization of different aspects of buildings to create views never seen before. 3D data can be used in all common CAD programs. FARO WebShare Cloud for sharing the scan data via the internet simple, secure, and can be used anywhere online. The resulting point clouds can be precisely modeled in Autodesk Revit.
3D modeling and laser scanning of a historic fountain
Benefits in Construction
Laser Scanning in construction can offer fast and cost-effective documentation of the entire construction process. Seamless capture and monitoring is critical for construction progress for legal and technical documentation, precise dimensional check of complex components such as free-form shape elements, documentation of deformation processes and monitoring of countermeasures., project coordination to help improved multi-trade project collaboration. Capturing scans at all phases of construction can aid in the case of final building inspections by being able to go back and visualize the entire construction process start to finish.
Structural Steel Clash Detection
Benefits in Property Management & Facility Maintenance
Building information models (BIM) is taken another step further here at PMC. We interject valuable asset information right into the living model. This way your facility can be on the cutting edge of maintenance and efficiency by utilizing autonomous features right through the model.
With the rapid changes during this time of COVID-19, it is a priority to ensure the health and safety of our customers, employees, partners, and communities. We are working diligently to reduce the risk for our team as well as yours. While PMC has physically closed our offices during this time our workforce is equipped with laptops, VPN access and conferencing tools to be able to seamlessly work remotely. We are committed to working toward planned deadlines and providing you support and services using various online collaboration tools and technology. Leadership and the management team here at PMC are continuously monitoring developments surrounding the COVID-19 outbreak. We will continue to communicate with our customers, clients, and partners to ensure we keep you informed in a time like this. PMC greatly appreciated our customers’ patience as we manage through these challenging times.
A Special Note to our Industrial Customers
In this challenging time having a reliable digital twin is one of the best ways of continuing your important plant design work while minimizing or eliminating the need for your engineers to enter the plant. The best and fastest way to get a reliable digital twin is the use of laser scanning. With manufacturing a critical business in most locations PMC is prepared to capture data safely in your facility.
PMC COVID Response
PMC staying safe on the front lines
When PMC comes to your facility, we will be taking several new, and recommitting to existing, precautions.
Providing complete PPE for our staff including hand sanitizer, masks, gloves, disinfection spray, and even Tyvek suites as required.
Restricting field crews to 2 people who will not interact with other PMC staff.
For higher-risk environments, our employees will begin weekly COVID testing as tests become available.
PMC has implemented new policies per CDC guidelines to help protect our employees who must be on site.
We have added disease prevention training to our mandatory training curriculum.
Our field technicians play a critical role. While their mission is to keep the data capture process moving, we recognize that there is a balance between providing service and keeping our technicians safe. To accomplish that balance we are providing them with new policies and procedures including social distancing, so both customers and field technicians feel safe working together. PMC has implemented disinfecting and temperature checks across all our operations.
PMC can achieve safe and effective work operations during the COVID-19 pandemic. To our family to yours, we hope all stay safe and healthy. For more information or questions regarding how PMC can help continue your project in architectural, construction, and engineering reach out to us by phone (313) 441-4460, email, Linked-in, Twitter.
In today’s post, we are going to dive deep into what it means to have a “clean” model and share some of the principles that guide PMC when completing models for our customers. Whether you are working in traditional CAD or a full digital twin BIM a clean model will function well on your project, minimizing the time taken to rework data as the project progresses.
Why a Clean Model?
A Model is clean if it can be understood easily – by everyone on the team. With understandability comes readability, changeability, extensibility, and maintainability. All the things needed to keep a project going over a long time without accumulating up a large amount of technical debt.