For some designers and engineers, 3D scanning physical objects to use as reference models can be the ultimate time-saver. Industrial Designer Eric Strebel is one such design professional—and as always, he has some insightful tips for fellow designers and engineers out there who want to kickstart their 3D scanning game—aka, photogrammetry.
Photogrammetry is a process in which a user takes photos of an object from different angles. Using these pictures, computer software calculates the form and size of an object and can recreate it as a 3D model. In his latest video, Strebel shows us how to prepare and scan a bottle using basic photogrammetry techniques:
First, the surfaces of the object need to be prepped for optimizing image capture—including removing surface imperfections and glare. To make the bottle non-reflective, Stebel first sprays the bottle with several colors of primer. He coats the bottle first in a grey primer, then switches back and forth between speckles of black and white primer to give it some texture. After spraying the bottle, he props it up on a makeshift stand using a hot glue gun.
Just as crucial for ensuring proper output is prepping the “capture space”. In Strebel’s case, he places the bottle and stand on his workshop table since it is flat and has good lighting. To make the images look better in post-production, he lays a sheet of white paper above the light as a diffuser while he takes photos of different angles of the bottle. For his camera settings, Stebel has the camera set to manual with the aperture as low as possible to blur out the background and so he can get good depth of field. He also has the ISO locked and the camera autofocused.
Once the photos are taken, he imports them into Agisoft Metashape—a stand-alone software product that performs automated photogrammetric processing of digital images to generate a 3D model—to generate the mesh of the bottle. The program determines the various angles where he took the photos and creates a transparent 3D image of the bottle. He cuts off the 3D model of the stand and surfaces the bottom of the bottle before exporting the finished data.
The bottle data can now be used in different CAD applications for different purposes. In theory, you can even 3D print the same bottle if you need to. While Agisoft Metashape carries a $179 pricetag for the Standard version, new users can try it for free for 30-days.
As always, you can find more of Eric Stebel’s videos on design and product making on his YouTube channel.