Photogrammetry can be used to create 3D models of buildings or objects. How? Overlapping images (at least 60% or more) are combined using photogrammetric software (Agisoft’s PhotoScan) to create point clouds which are then translated into a 3d mesh. The mesh is covered with a texture comprised of photographic images giving it color and detail. The mesh can be edited, patched and altered using another second party software such as Mesh Lab (allowing the user to make measurements and stitch the mesh) The method that we’re describing below is the working methodology for applications of photogrammetry that involve conservation. This approach use non- proprietary software and archival preservation formats.
What to avoid:
You can either use the Agisoft Lens software (an automatic lens calibration software, which uses LCD screen as a calibration target. It supports estimation of the full camera calibration matrix, including non-linear distortion coefficients). Your shooting approach differs based on your processing choices:
If you utilize Lens you’ll only need to take one image per angle. If you don’t use Lens you’ll need to take a 90, 180, and 270 shot per angle.
background of your photos. 2. Convert RAW files to .DNG’s to archive and then convert to .jpg for processing.
Place in a folder. Then begin the processing of your files in Agisoft. See here for details:http://okeeffeimagingproject.wordpress.com/2012/08/26/photoscan- processing/
F. Then press apply, click calibration and then close. G. Now, back to Photoscan in order to prepare your mesh.
A. If needed, mask images, by making a selection then [command+shift+a] to add more to it. Select parts of photos to mask out with rect. marquee or intelligent scissors. Command z to undo.
B. Align photos (high, disabled) takes several hours depending on images Point Cloud.
C. Workflow>Build Geometries (longest step) Use medium setting.
i. Setting: Object Type: Arbitrary
D. Workflow>Build Texture (fastest step). Then View>textured.
E. File>save then File>export mesh (make sure to save all files in same location-HD)
CLEAN the mesh :
1. Models can be finessed and edited Photoscan and then further finessed in Meshab. You’ll want to save your file as an .obj file for editing and repairing in Meshlab. Save your file as a .stl for 3d printing.
Real world applications?
You can use your generated mesh in several ways: