Mini chapter I. Washing the body / II. Fixation. Photo recording / III. Scan in 3D
Mini chapter I. Washing the body
The first thing after testing is that the boat goes into the wash. Its difference from the usual one is the use of stronger chemicals to wash away old deposits and dirt. We write down everything we see, especially carefully studying old problems - impacts, repairs. We are looking for cracks, chips, traces and manifestations of osmosis.
Washing should always occur if there is suspicion of dirt, traces of grease, etc. When dirt remains, or, moreover, traces of lubricant, not a single resin, not a single glue will be able to fulfill its function! Also, under the dirt, you may not notice important details: chips, cracks through which water penetrated and destroyed the body from the inside. You can do the work, but because of such details it will be useless: there will be no adhesion of the new layers of laminate to the old ones, the soil will not lie down, the embeds and amplifiers will not stick.
II. Fixation. Photo recording
Fix everything and a little more!
During the work process, we will need to find out some elements, details that were there initially - before starting work. And time cannot be turned back. For this reason, we always take photographs of general and larger components, junctions, and transitions of the body. Mechanisms, etc. Everything that we have touched or will touch + more photos of the appearance - general ones. They always come in handy. Photos take up less space than videos. Further search is faster and more efficient using photos than hours of video. Since photography is never three-dimensional - one “eye” - one lens, then it is advisable to take photographs of the same object (area) from different angles (sides).
In addition to images and the appearance of objects, it is useful to understand distances and scale. Adding a tape measure to a photo, or even better, a pair with an angle of 90 degrees between them, increases the chance of understanding the distance between objects. In a professional environment this is called measurement photography.
For this shooting, regardless of the camera or phone, there are rules that always lead to a good result:
- The shooting is done with a 50mm (80mm) lens/the shooting is done with a phone lens with X1 zoom, i.e. the lens is not telephoto or wide-angle.
- Photos must be clear. No blur. Let's understand shutter speed and lighting.
- Do not use high ISO values (working 100-500).
- Light. One of the main ones. In the dark, nothing is visible, especially the small details that we need.
- We do not use filters or photo processing. We are for naturalness.
- If the object is large and long, then we don’t shoot from one point - we walk parallel to the object and maintain approximately the same distance to it. If the object is isolated, then we shoot it from several angles.
About the rulers and their location.
A scale ruler is placed next to the object. It is placed in a free part of the space: either parallel to one of the sides of the frame, or parallel to the larger side of the object, symmetrically to the edges. When photographing flat objects, the ruler is placed in the same plane as the object; when shooting volumetric ones, it is installed either in the plane of location of characteristic parts, or in the plane with the maximum dimensions of the object: for cylindrical ones (bottles, cartridges, bullets, etc. =)) - at the level of the axis; for edged weapons - in the plane of the blade. A gap of 2-3 mm is left in the image between the scale ruler and the object being photographed. (excerpt from a textbook on criminology).
III. Scan in 3D
When solving most problems, the methods described above are very helpful. To more accurately measure and save the image in our workshop, we use the photogrammetric method, which in simple terms means using a 3D scanner. Thanks to which we can work in three-dimensional space at the computer and calmly design parts and assemblies, while at the table with a cup of tea and in a comfortable environment =). The scanner makes it possible to view the desired object from any angle and measure the distances between any points at any time =).
If you need to get a 3D model of a small object and don’t have a professional 3D scanner at hand, you can use the photogrammetric method of shooting using a smartphone camera. You will have to suffer, but you can get a 3D model, and it will not differ much in accuracy from a professional 3D scanner costing $20,000. The difference in accuracy is 0.3 mm. =) Find out more about the method on the Internet. (For example: photographing –> Meshroom app –> MeshLab –> Netfabb).