Abstract: A method of additive layer manufacture includes the steps of successively depositing layers of fusible powder material in overlying relationship and introducing energy, such as by an electron beam, into each deposited layer to selectively melt material in the layer so as to fuse the melted material together and to already fused material of a layer thereunder in order to produce a three-dimensional solid article in successive cross-sectional layers. In order to monitor layer quality, structured light defining a fringe pattern is projected onto each deposited layer before and/or after melting of material in that layer and the fringe pattern on each layer is imaged from a perspective different from that of the projection so as to reveal disturbance of the pattern by topographical features of the layer.

Abstract: A method of additive layer manufacture includes the steps of successively depositing layers of fusible powder material in overlying relationship and introducing energy, such as by an electron beam, into each deposited layer to selectively melt material in the layer so as to fuse the melted material together and to already fused material of a layer thereunder in order to produce a three dimensional solid article in successive cross-sectional layers. In order to monitor layer quality, structured light defining a fringe pattern is projected onto each deposited layer before and/or after melting of material in that layer and the fringe pattern on each layer is imaged from a perspective different from that of the projection so as to reveal disturbance of the pattern by topographical features of the layer.

Abstract: A method of identifying characteristics of a target, marking object comprising the steps of: providing a subject, marked article having a surface having markings caused by a marking surface of the target, marking object; obtaining a 3D dataset corresponding to a 3D virtual model of the surface of the subject, marked article by means of a sensor; extracting from dataset by means of a surface segmentation analysis data indicative of a class of the target, marking object and storing said data in the database; extracting from the dataset by means of a surface wavelet filtering operation data corresponding to one or more individual characteristics of the target, marking object and storing said data in the database.