Camila Kleis Rodacki
Owner partner at WRodacki
There are numerous methods and equipment on the market that aim to capture reality, that is, to bring a structure from the real world to the digital world. We highlight the 3D laser scanning whose product is a cloud of points, which are nothing more than thousands of points dispersed in space, with XYZ coordinates, corresponding to the boundaries of the geometries. This point cloud can be transformed into a mesh or a 3D model.
There are important considerations when hiring, as in 3D laser scanning the range of possible configurations at the time of survey is enormous and directly affects the budget and the final product. For comparison purposes, in laser scanning with fixed equipment, a single scene can vary between 1 minute and 2 hours, depending on the resolution and quality settings selected by the operator. To define these settings, knowing the project and the customer's needs are essential so that the delivered product is not lacking in information or having too much of it. Compared with other methods on the market, the 3D laser scanning process is one whose point cloud can have a higher resolution – a greater number of points – which results in a higher level of detail and with high precision.
But how to hire a point cloud?
Understanding the ultimate goal and the use that will be made of the point cloud is the first step. Regardless of the area of operation, it is essential that the client has defined what information needs to be collected during the scan so that it can be made available later.
To help with this first step, here are some questions to be answered:
Do you need a spatial idea or architectural/mechanical details?
What level of accuracy is required: millimeters or centimeters?
What is the maximum distance between points in the point cloud? Think about the items to be captured and their dimensions. Helps pinpoint the expected level of detail.
Does the place to be surveyed have lighting, whether artificial or natural?
Do you need color information or is a grayscale point cloud sufficient?
How big are the elements to be captured? Are they large structures or small parts?
Do the objects to be lifted have a polished surface, shiny, too dark or too light?
With these answers, your supplier will know how to indicate the best solution. As a customer, it is important that you know some key items for hiring. Here are some tips:
The higher the resolution of the point cloud, that is, the closer the points are to each other, the greater the level of detail, but the more expensive the collection in the field and the larger the file size;
If the environment does not have light, whether natural or artificial, laser scans work perfectly, but the point cloud will be in grayscale;
The more location information you have, such as plans, photos, etc., the more effective your budget will be;
The number of rooms or rooms in the site has more impact on survey time than the total area;
Not all equipment has the option of providing a colored point cloud in the actual colors of the location. Therefore, it is important that you know if this is relevant to you at the time of hiring;
Point cloud files are generally heavy. But there is the possibility of reducing the cloud point density and, consequently, reducing the file size;
The final accuracy of the survey is determined by the accuracy of the equipment (local error) added to the error arising from the union of scenes, or recording of scenes (global error). Therefore, it is not enough to know how accurate the equipment is. This is just a beacon;
If data confidentiality is important to you, be aware of the confidentiality clauses in the contract. Some companies work with data sharing;
When comparing proposals, pay attention to the configurations of the equipment used, as well as the deliverables included in the proposal.
There is no perfect lifting setup, there is one that is best suited to your use. That's why this initial conversation between you and your supplier is important. Each equipment offers a multitude of configurations at the time of the survey that directly impact the budget. Only by knowing your needs and how you are going to use the final product will it be possible to achieve optimal cost-benefit ratio.