What is a Point Cloud?
Put in the simplest sense, a Point Cloud is a dataset that represents objects or space.
What is Point Cloud Scanning?
Point Cloud Scanning is the process by which these point clouds are collected. A massive number of single data points are placed into a set that can then represent the object or space that was scanned.
The individual points are represented along the X, Y, and Z cartesian coordinates creating a 3D view of your site's as-built conditions. This 3D view is a very powerful and helpful tool that provides an invaluable source of visualization, measurement, and analysis for engineering and design projects.
How are point clouds created?
Scanning
The most commonly used equipment for creating point clouds is a 3D Laser Scanner with LiDAR (light detection and ranging) technology. These scanners record a massive amount of data points that return from every surface in the area that is being scanned. Surfaces can include doors, windows, walls, MEP equipment, ductwork, and steel structures.
LiDAR uses infrared light laser pulses to measure distances. The pulses are reflected back to the sensor and the scanner measures how long it took for the light to return. These laser scanners can emit up to 100,000 pulses per second, which gives an incredibly detailed view of the area being mapped and cuts out a tremendous amount of time and effort.
Process
3D scanning allows for a world of data at your fingertips, you just have to know what to do with it.
The data collected from the scanner is useless until it is processed. This process includes registration (aka stitching), cleaning out the "noise", extra data points that are not needed, and file conversion so the data is readable by and compatible with other software (Revit/Inventor/AutoCAD and other viewing software).
The registration process consists of accurately compiling individual scans to cohesive point clouds. The process produces a point cloud that can be used for modeling and measuring from the raw scan data collected.
As soon as the point clouds are registered, you can import them into software to visualize the area. Once imported into the software, the data will appear as a pixelated, digital version of the site. This pixelation is due to the image being made up of the immense number of individual points that were collected. The pixels can be thought of as the pixels in a picture and the denser your point cloud is, the more details you will see within your image. These pixels, when combined, create an identifiable 3D structure.
From this software, the data can be defined, manipulated, and modified to suit the user's needs. This software includes Autodesk Revit and/or Inventor, where the data can be turned into 3D solids and surfaces.
Correct registration allows for the most accurate measurements as well as the best drawings and models for your project. Registration also allows for the most accurate documentation of the as-built space with accuracy down to the millimeter.
This whole process is completed by trained CAD Technicians who help ensure adequate collection of data and efficient scanning methods.
How Point Clouds are imported into CAD or BIM.
There are many different point clouds file formats, each serving its own function. Some common point cloud file formats include PTS, XYZ, E57, LAS, and PLY.
.PTS is an open format for 3D point cloud data. This format can be used by anyone because open formats are maintained by standards organizations.
.XYZ is an archetypal American Standard Code for Information Interchange (ASCII) format. This means that it is compatible with many programs, but it has no unit standardizations. This can cause data transfers to be more difficult.
.PTX can only be used on organized clouds, not on unordered ones. This is a very common format for storing point clouds, usually from LiDAR scanners. This is also an ASCII format.
.E57 is a format that is vendor-neutral and compact. This format can store point clouds and metadata from 3D point cloud data, such as intensity and color.
.LAS is an open format designed for data obtained from LiDAR scanning. It can also accommodate other point cloud data records. It combines GPS data, laser pulse range information, and inertial measurement units (IMU) to create data that fits on the X, Y, and Z axes.
.PLY is known as a Polygon File Format. This file type stores data from 3D scanners and accommodates properties such as color, texture, and transparency. It can contain data from both the point cloud and the 3D mesh.
When you are choosing a file format, make sure that you choose one that can convert your point cloud into one that is compatible with your chosen CAD or BIM solution.
Why are Point Clouds necessary/awesome?
Even on a small project, using point clouds to collect data increases your efficiency and overall work experience. Surveying sites manually can stretch out a project's duration and require a bigger budget but point cloud scanning can help streamline the process.
Renovations or retrofits that must be done while an area is still in use add another layer of difficulty. With point clouds, this becomes much easier, allowing for limited or no downtime while measurements are collected. High-tech modeling software solutions and laser scanners ensure that every possible object is identified and distinguished from all the others.
Point Clouds also offer better efficiency, precision, and savings.
Efficiency
Point Clouds have multiple ways of creating increased efficiency for your projects. Manual measurements are made obsolete and once registered, manipulating these point clouds provides an enhanced preview of possible clashes or other interferences. This efficiency leads to starting and completing your work sooner. Data collection is also faster because of the large number of points that can be recorded at once.
Precision
Laser scanning delivers quick and accurate results. These scans transform a living landscape into a digitized 3D model. Ground-based LiDAR can produce results that are accurate within a millimeter-scale. These lasers can penetrate through dense vegetation for a more comprehensive site view sometimes than even seeing it in person. LiDAR also often incorporates other features such as GPS to ensure that each scan comes with the most accurate information possible.
Savings
Point Clouds can allow you to plan a more effective budget for your projects because of the greater precision involved in site mapping. This can help you avoid going over budget as you will have fewer chances of running into any costly mistakes or unexpected expenses. Laser scanning also saves you money by eliminating the need for manual surveying, which reduces the cost of hiring additional labor. Money will be saved with decreased or eliminated expenses and you will also earn more overall on projects. Increased accuracy levels can lead to more trust from clients in completing their assignments. This will help to boost your reputation and encourage more companies to do business with you.
Value of Point Clouds.
Point Clouds are used to provide a computerized view of your site's as-built conditions. Once the point clouds are registered by an experienced technician, they are imported into software to visualize the data. From this software, the data can be defined, manipulated, and modified to suit user's needs. Custom deliverables, such as 2D drawings and 3D models, can be provided at any level of detail and are used for analysis, design, construction, renovation, prefabrication, and facility modifications. New equipment such as ducts and pipes can be successfully routed and placed without interfering with existing equipment. Through this process, interferences and collisions can be avoided on a computer far before they can happen in the field. This in turn saves each client valuable downtime and money.
Point Clouds are also very useful in creating an as-built view for historic buildings and structures that don't have existing plans.
JBW offers Point Cloud Scanning to provide our client partners with increased efficiency, precision, and savings. Increased efficiency is delivered by saving hours of time that would normally be spent in the field or manipulating data. Precision is provided in the sense that ground-based LiDAR can produce results that are accurate within a millimeter-scale and incorporates features like GPS to ensure each data point comes with accurate information. Increased savings are seen because a more effective budget can be planned for your projects and you can avoid going over budget by providing fewer chances of running into any costly mistakes.