As an essential parameter, accuracy attracts much more attention from people who are going to purchase 3D scanners. Usually, the accuracy information of a 3D scanner is introduced in the specification, but is the accuracy of the manufacturer labeled in accordance with that of the real one? Sometimes, we hear from customers that they can’t get a 3D model as good as the seller presents. So how can we test the accuracy by ourselves when getting a 3D scanner?
When a professional user tests a 3D scanner, accuracy and details indicators are their focuses. The accuracy refers to whether the dimension is accurate, and the details refer to whether the details meet the expectations. Today, we are going to concentrate on how to measure 3D scanner accuracy.
Typically, professionals in the 3D scanning arena use standard measurement tools such as a Ceramic Standard Ball, Ceramic Calibration Plate, Step Calibration Block, etc. These measurement tools have specific known attributes and dimensions, and accurate results can be obtained.
For example, we use a Ceramic Standard Ball to test the accuracy of the Revopoint POP 2 Scanner. How accurate is Revopoint POP 2 3D scanning? Here is the test process:
This video displays one of the standard measurement methods. From the test results, we can see that the two-ball center distance on the Calibration Report is 100.0397; scanned by the Revopoint POP 2 is 100.011898. The difference between the data from National Hi-tech Metrelegy Station and the Revopoint POP 2 is 0.027802, which means that the accuracy of the models scanned by the Revopoint POP 2 are much better than 0.05mm.
While if you don’t have the standard measurement tools (or the actual values are unknown) and want to know a 3D scanner’s accuracy level. A caliper suffices. You could use a caliper to measure the subject and compare it with the dimensions of the scanned 3D model. However, we have two suggestions:
1. When you measure the dimensions of an object with a caliper, you should use the average values after multiple measurements to avoid errors due to the manual operation of the tool.
2. When performing dimensional analysis on the scanned model data, it’s better to choose Fit Cylinder or Fit Plane rather than randomly selecting only two mesh points as your reference.
Here are some examples:
Check these pictures and guess which are accurate?
Yes, the first and second ones apply the proper measurement method, while the third is questionable. Why? If you choose two points randomly, you cannot make sure that the two selected points represent the accurate distance between those two features.
Therefore, if you want to test the accuracy of your 3D scanner, it’s recommended to use standard measurement tools. And if you don’t have these tools, a caliper can help you out, but remember to take multiple measurements and average them. When analyzing the model data, do NOT randomly grab two points of the mesh directly, for the result will probably be inaccurate.
Hope you can get the more high accuracy models by your 3D scanner!