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Getting your head around 3D scanning technology is difficult. It's loaded with lingo and it's not a simple thing to grasp for anyone, even people with extensive training in 3D graphics. This short article hopes to provide a short pictoral summary of how to scan real object to a usable 3D model minus all the gory details.
1) Setup and calibrate your 3D scanner and work environment.
To start you'll need to setup your 3D scanner. Whether it's FlexScan3D or another scanner you'll need to setup your scanner in a clean work area for the scanner and the object. Problems fixed further upstream is way easier to fix than downstream in another program. Correct camera setup is the #1 difference maker between a good scan or bad scan. Make sure the exposure settings are good and the focus is correct. This applies to any 3D scanner, if your source data is no good, there's nothing any amount of software or technology can do to help you.
2) Prepare the object to scanned
Prepare the object to scanned, this often involves coating unscannable surfaces such as glass, chrome, and very dark areas. In our example below, we use white masking tape to coat the really dark areas.
3) 3D Scan the object
The step better known as the beginning of the end, the scanning step is often the least painful step. Your the end result is a point cloud. With FlexScan3D you also get a high resolution texture as well. You will need to scan multiple sides of the object to get full coverage. There will be areas that can't be scanned. (The inside of a tea pot for example)
4) Point cloud Cleanup
The resource center provides links to various programs that perform this task. The point clouds should be brought in to a 3D scan processing program and any outlying points deleted, and noise deleted or smoothed over. It's rare to get a perfect 3D scan with zero defects. Some scan processing software only triangulates well with consistantly placed points, so you may need to pre-filter your point data to get it in to a format it likes. FlexScan3D outputs both raw points, and filtered points.
5) Mesh Trianguation (Optional)
Triangulate the various point clounds You may want to trianguate after the scan alignment, depending on the software package and your particular use case. There are pro's and cons to each method depending on how you plan to use your scan data.
6) Scan Registration / Alignment
With multiple scans you'll need to register or align the scans together to be merged. Use one of the fine 3D scan processing packages available, or a free one like Scanalyze. In the picture below we've aligned the scan point clouds. With multiple scans, the scans are in a similar spot in 3D space. The scans need to be moved to where they would natually be in the real world. 3D Scanners use a variety of methods to aid in this process but none of them are fool proof, so we have to do some sort of manual alignment no matter what.
7) Scan Merging and triangulation
Once all the scan segments are aligned, merge the scans and trianguate them in to the final mesh
8) Mesh Cleanup
At this stage, generally the mesh may have holes, bumps or simply excess data that you don't want. Clean this up in your favorate Scan processing or geometry cleanup package via various scan clean up tools. Depending on the size of your mesh this can be a very labor intensive process. Coming in with clean scan data will make this step nice and quick, if the data is noisy it can often be better to just rescan the data with better settings.
9) Scan Texturing (Optional)
You may not need a texture, in that case, skip this step. If you need one bring your final mesh back in to FlexScan3D and use using the auto texture option to apply the texture on to the mesh. It's automatic. WIth multiple scans use our 3DSMax plugin to project the UV co-ordinates on to the scan. This will allow you to apply multiple textures on to a single mesh, and then merge the textures in to a single texture.
10) Scan Data Conversion
Convert the highpolygon mesh surface to other formats for use in industry standard applications such as low polygon representation(obj) , NURBS or a (STL) solid model. Your scan processing software package will can help you do this, check the resource center to see the available options. In our case we brought the model in to 3DSMax, decimated it to less than 2K polygons, used the high resolution model as a normal map and made a short video of it. How do you do all that? We're out of steps and that's an article for another day.
