Survey work play an important role in my workflow. Tensile Structure allows very small amount of error for steel frame fitting (2-3 cm). If the survey data is wrong, steel frame will not fit in, and the cost of re-work could be very expensive. I believe all designer and contractor have been aware of this.
My old school method of surveying is by using a total station. It is still most accurate method to get points in 3D space (Error < 3.0mm) But there is a draw back. I can only collect one point at a time, for large project I would need to collect 30 - 40 points just to make a 3D model. This is very exhausting. Sometime the line of sight is blocked, and I need to relocate the station, this will induce error and it will accumulate as the number of time that I move the station.
Tree branches are one of the hardest data to collect as you can only measure the center point of the stem, point by point and the diameter of the stem is unknow.
Curve wall will hinder line of sight force surveyor to re-locate the station and add error into the data.
This all changes when the LiDAR Scanner came along. It shoots out millions of laser points and collect all the data in a real time. Trees and even electrical wire are also captured. Not all scanners create equally, the one we use has smaller error, less than a centimeter and the point cloud quality is so crisp and clear without any noise or artifacts. The 3-story house above only take 6 minutes to scan, both indoor and outdoor (200 m2)
For larger area, we attach GPS receiver with RTK (Real Time Kinematics) to the scanner and this help coordinate correction and keep absolute error within 15mm (end to end measurement) even with a long-distance over 1000 meters.
Millions of points captured instead of 30 - 50 points from the ordinary method. We are now flooded with data. Point cloud is difficult to handle, it surely looks like a photograph with 3D view rotation, pan and zoom capability. The distance can be measured between points, but it is not easy in practice at least for most users.
To put this point cloud to a good use is by converting it into 3D CAD model. Architect and designer can then use this model to further develop their work or doing extension structural design and calculation. With quality point cloud, this can be done automatically without error or loosing detail.
The 3D CAD model can be transformed in many formats, Revit, Sketchup, AutoCAD, Blender, 3DsMax or universal 3D file such as OBJ, STL, IGES or SAT.
Furthermore, the 3D model can also be converted into plan, projection, and section drawings automatically, this ca be useful for designer, contractor and building permit because 2D drawings are best suit for dimensioning. The 2D drawing can be export into AutoCAD file format.
Above is an example of 3D section views which is good for illustration and planning.
This is the first step in building renovation design. Accurate and complete data will save you time and money. If you are interested in this service. Please contact us for pricing and detail.