Visualisation in 3-D can significantly improve the interpretation and under
standing of imaged NDT data sets. The advantages of using 3-D graphics to a
ssist 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 combi
nes the analysis features of established 2-D packages with facilities for r
eal-time data rotation, interactive orthogonal/oblique slicing and 'true' i
mage reconstruction, where scanning-surface shape and reflection from compo
nent boundaries are accounted for through interaction with the full 3-D mod
el of the component. A number of novel facilities exploit the graphics capa
bility of the system. These include the overlay of 3-D images with individu
al control of image transparency; a floating tooltip window for interrogati
on of data point co-ordinates and amplitude; image annotation tools, includ
ing 3-D distance measurement; and automated defect sizing based on '6dB dro
p' 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 pa
rameters and scan pattern on the component. The output is presented as a si
mulated ultrasound image.