Fringe projection simulation software for 3D shape measurements

Profilometry with LCD or DLP beamers has become a common three-dimensional scanning technique[1]. Many attempts are made to enhance the accuracy of these measurement systems, by developing new algorithms or improving the existing ones. Comparing these algorithms to the existing methods requires building a validation setup. This validation setup has to be carefully calibrated to obtain realistic measurement data. Additionally the distortions of the different components need to be compensated. Building these setups often takes a lot of valuable research time while the goal of many research projects is to improve the mathematical fringe analysis tools without having to deal with practical problems of a test setup. This paper presents the ‘Fringe Projection Simulator’, a program which can simulate three commonly used fringe projection setups. All three setups contain a beamer and a camera with a diverging lens. The program is available for download free of charge at: http://www.fringesimulator.com. Introduction Three-dimensional measurements have become a common quality control technique in modern factories. Different measurement time requirements have lead to the development of different techniques such as laser line scanning, grid projection and Moiré profilometry. Within the group of fringe projection techniques a subdivision between spatial and temporal methods can be made. The software presented in this paper can simulate both methods, which allows you to compare their results. Validation of three-dimensional scanning techniques can be time consuming and strenuous because a small error in the setup can lead to large errors in the measurements. Various factors such as the distances between the components, the surface quality of the object and lens distortions can affect the results tremendously. Therefore, if the results do not meet the expectations, discerning the cause can be very difficult. This task would be made much easier by simulating the results first. Performing simulations the traditional mathematical way is possible if the objects are not too complex. Creating complex objects with mathematical software is time consuming. The ‘Fringe Projection Simulator’ however, is designed to support STL files. This enables the user to create a 3D model using any CAD program. 10th IMEKO TC14 Symposium on Laser Metrology for Precision Measurement and Inspection in Industry Braunschweig, GERMANY, 2011, September 12-14