This is the first article from a series of articles dedicated to efficient scanning and post-processing of huge objects. First of all, let's define what is a "huge" object.
According to our experience, our clients successfully 3D scan and process the following objects that may be defined as large or huge:
- Cars, vehicles, helicopters, planes, trucks, boats
- Statues and monuments
- Parts of buildings
- Industrial elements like turbines, pipes, etc
Photo from the scanning session of the huge statue of Napoleon (check the whole case study here).
1.1. Protection from the sun
Whenever you 3D scan outside, consider using any protection (tent, umbrella, etc) to avoid direct sunlight. Such sunlight may over-light the pattern which is projected on the object by the scanner and which is in charge of 3D reconstruction.
Scanning in the early morning or in the evening (and even at night) is also an option.
Photo from a newspaper, when Artec Partner (4CCCC) scanned a huge statue with Artec MHT.
Use a tablet or portable light laptop plus battery for your Artec scanner. You can use Artec battery without charging for up to 6 hours.
Advice from Artec Partner Shonan Design: always have a spare battery for your laptop. According to his experience, Artec 3D battery lasts much longer than a standard battery in the laptop.
1.3. Contrast and pattern
When you 3D scan in "Geometry + Texture" mode, Artec Studio saves special grey scale type of texture. This texture is used both for tracking in scanning mode and for registration algorithms in post-processing mode.
The general rule to keep in mind: if your huge object has large flat parts without any geometrical or texture features and you consider adding extra texture pattern on them, make sure your pattern is contrast to the background. For example, avoid using pale grey pattern over pale yellow background (projected into grey scale, such pattern and background won't be contrast to each other).
The picture below illustrates the conversion of pale yellow&green into grey scale made by Artec Studio:
Note: If you are interested how this grey scale texture is used for post-processing, check this article for more details.
Useful scanning settings in Artec Studio
2.1. Faster saving
- Since you are dealing with a huge object, SSD will be useful for fast save of all raw data in the project.
- To boost the saving process speed, consider using "Maximum compression" in Settings → Performance → Data-compression level. This option is available starting from Artec Studio 12.
2.2. Back copy scan data to disk
- Save existing project (or just an empty one) to unlock this option in section Scan → Advanced.
- As soon as you stop scanning with this option enabled, all scanned data is automatically saved on your hard-drive and unloaded from RAM.
2.3. Prefixes for scan names
- Consider setting prefixes in Scan → Advanced → Prefix prior to scanning process to assign names for all scans that you will capture.
- You will easily detect the parts of an object when you start the post-processing all these raw scans afterwards.
Example: if you are scanning the car, you can raw scans divided into groups like "Wheel", "Front panel", "Bottom part", etc.
3.1 Plan your trajectory
- Plan your trajectory ahead (front part - side - back part - another side)
- Keep in mind what areas you have scanned already to make sure that you have captured all parts of your object from all angles
3.2. Use these techniques
- When scanning large flat areas (with texture features), do not hold the scanner at one spot for a long time. Try not to scan simple areas too slow, to avoid capturing too many frames.
- Use Auto-alignment in the process of scanning (with the Pause button or with the help of "Auto-align new scans with those marked in Workspace" box) - this will save you time on post-processing alignment. For instance, you have 3 scans of 1000 raw frames each, rather than one 3000-frames scan. Also, smaller scans are easier to edit
- Check scans for holes (unscanned areas) after each scanning session and unload every 5000 frames to disk to save RAM.
- If the highest accuracy possible is your goal (besides 3D-capturing the object), then make sure that there is enough geometry and/or texture features in scanner field of view at every moment of scanning.
Reviewing scanned data
After you finish scanning the object, it's time to quickly review your data to check that you have captured everything and no extra scans are needed.
- Use the option "Open project (Unloaded scans)" to quickly open your project.
- Use option "Load key frames only” to quickly preview your raw scans.
- Mark duplicated data by renaming the scan.
Congratulations, you have just scanned a huge object! Also, we recommend checking post-processing tips and tricks for huge objects that are listed in this article.
Our team is here to help! If you have any questions or issues, please do not hesitate to contact us by emailing firstname.lastname@example.org or by clicking on "Submit a request" button at the bottom right side of the screen. We will always be happy to assist you and will get back to you as soon as we can.