Today technology allows just about anyone with a smartdevice to scan real world objects and turn them into 3D models but there’s still wide variability in the accuracy and usability of these models as far as integration into virtual scenes.
Photogrammetry and light detection and ranging (LiDAR) scanners are two methodologies for producing point cloud data sets from real world objects or spaces. These point clouds record points in space representative of the surfaces in a scanned area.
Photogrammetry stitches together multiple images to computationally estimate distances between the points that make up an object, assembling a point cloud to construct a 3D model.
Apps like polycam are commonly used on smartphones and tablets as they have the ability to perform photogrammetry using the camera. Distinct backgrounds and many photos from many angles are necessary to build a decent facsimile of the object.
Because the software is using 2D images to assess edge detection and distances it may have trouble distinguishing foreground from background or textures and can make mistakes.
Here is an example of why photogrammetry, while often more affordable and fast may not always produce the best quality models.
Often images of more angles of the objects, better lighting, or choosing a different computational software to build the assembly, can correct some of these challenges but overall these aren’t the best resources to bring an object into the virtual world.
A laser is a coherent beam of light- meaning all the photons have the same frequency and direction (the peaks of the light waves align in space and time).
Laser light scanning is a far more accurate means of detecting the distance between points on the surface of an objects because it uses the time it takes for light to bounce off a surface and reflect back to a sensor in order to more accurately assess distances. There are white light and blue light scanning devices where blue light are the most accurate available scanners on the market today. The Artec Space Spider is a blue light laser scanner at the maker commons available to students and staff through online appointment https://makercommons.psu.edu/technologies/3d-scanning/ .
Often real skulls are expensive fragile, and some have broken pieces or tiny parts that are difficult to resolve at this scale. The ability to scan these learning resources allows them to be reproduced with sturdier materials at low cost. For example- while a grizzly bear skull can cost over $1000
These qualities make them good candidates for scanning these objects to build explorable learning resources at true or altered scale!
In this example a grizzly bear and raccoon skull were borrowed from the Veterinary and Biomedical Sciences (VBS) department and scanned to build 3D models. In this format these skulls can be great tactile and explorable learning resources for courses like comparative anatomy.
Some students may have auditory or language processing challenges that make standard lecture and slide based teaching styles less accessible. For this reason many instructors have been moving toward options that allow for more hands on learning which increases engagement across multiple learning styles and helps to bridge these kinds of learning difficulties and disabilities. The ability to access information in more than one format allows for students to adapt their study in ways that suit them best.
Here are the results of the scans of the two skulls uploaded to Sketchfab for easier sharing and download.
These models can then be shared via link to be 3D printed, or exported to a virtual space that is accessible via smartphone, tablet, desktop or VR headset.
The models produced by these scans are highly detailed which can make them computational heavy for some kinds of applications. This issue can be resolved through reducing the polygons that make up the mesh in programs like meshlab.
https://support.shapeways.com/hc/en-us/articles/360022742294-Polygon-reduction-with-MeshLab
Pt II details the process of bringing these models into AR/VR and 3D print here: https://sites.psu.edu/ericakrieger/2023/02/14/scanning-pt-ii/