3D Scanning for museums Kirk Martinez University of Southampton

Overview Why? Techniques available Laser image-based Summary

Motivation 2d representations don’t capture 3D objects well Any 2-D view can be generated from a single 3-D model. 3D studies can be done models can be compared/searched

Examples of scanners Cyberware Digibotics3dscanners Mensi Polhemus

Structured light scanning example from CNR Italy

Michelangelo project by Stanford used Cyberware

Arius 3D laser based – developed by CNR Canada RGB lasers give colour

Issues Some objects can be very large e.g. building Objects can be very complex e.g. lots of holes Lighting conditions often very important File formats and browsers Cost

Image-based 3D reconstruction techniques Image sequences of rotating objects Two approaches used: –Silhouette-based only approach: CANON software –Silhouette and multi-stereo technique:GET-ENST approach For less complex objects with textured surface Required: –good quality image sequences (precise turntable, good lighting, photographic know-how) –good silhouette segmentation

Turntable approach ENST scanner

V&A dual-cameras saves camera setup faster

3D laser acquisition & reconstruction Using MINOLTA Vi 900 laser scanner (ARCHIDATA) Using reconstruction software –Rapidform® (C2RMF, Cherbourg) –Maya® (Quai Branly) User partners involved –White clay Gallo-Roman figurines and moulds: C2RMF - Bourbon-Lancy C2RMF - Moulins –Miscellaneous C2RMF - Cluny Cherbourg Quai Branly (external partner, negotiation for collaboration in progress)

Outdoor scanning example Coloseum in Rome with Minolta laser scanner

3D Laser: Cherbourg Cherbourg_laser 17Cherbourg_laser 13Cherbourg_laser 12 Cherbourg_laser 03Cherbourg_laser 18Cherbourg_laser 14

Image-based 3D reconstruction: VAM 33 objects: statuettes, ceramic French vases

GET-ENST silhouette and multi-stereo technique

3D Image-based 3D Image acquisition Camera calibration 3D Reconstruction Texture map creation

57639 sommets, triangles Results

sommets triangles sommets triangles Scanner laser 3D Minolta Methode proposée Results compared with laser

47159 vertices, triangles Results

bigHeadbuddhadragon masquetwins african3 Image-based 3D reconstruction: GET-ENST Examples

Summary Cost / quality / time trade-offs Techniques vary in: mesh quality texturing quality some scanners are better suited to some materials smaller 3D models are simple to put on Web