The role of 3D graphics in NDT data processing

Visualisation in 3-D can significantly improve the interpretation and understanding of imaged NDT data sets, The advantages of using 3-D graphics to assist in the interpretation of ultrasonic data are discussed in the context of an advanced software environment for the reconstruction, visualisation and analysis of 3-D images within a component CAD model. The software combines the analysis features of established 2-D packages with facilities for real-time data rotation, interactive orthogonal/oblique slicing and 'true' image reconstruction, where scanning-surface shape and reflection from component boundaries are accounted for through interaction with the full 3-D model of the component. A number of novel facilities exploit the graphics capability of the system. These include the overlay of 3-D images with individual control of image transparency; a floating tooltip window for interrogation of data point coordinates and amplitude; image annotation tools, including 3-D distance measurement; and automated defect sizing based on '6 dB drop' and 'maximum amplitude' methods. A graphical user interface has also been designed for a well established flaw response model, which allows the user to easily specify the flaw size, shape, orientation and location; probe parameters and scan pattern on the component. The output is presented as a simulated ultrasound image.