PHOTOGRAMMETRIC METHOD TO 3 D SCAN INSECTS Erika

PHOTOGRAMMETRIC METHOD TO 3 D SCAN INSECTS Erika Bowen | Dr. J. B. Sharma and Forrest Ables | University of North Georgia Materials Abstract After discussing the problem of scanning small fauna in the UNG 3 D printing lab with Dr. J. B. Sharma, we collectively set out to conduct a research project to determine the quality and accuracy in replicating insects using a cellphone camera and Agisoft: a photogrammetry-based software. A photogrammetry guide to mount the phone controlling lateral and forward overlap was built with woodworking and the Boss Laser. With this guide, 3 insects were scanned, analyzed, and measured within Meshmixer, 3 D modeling software, and compared to the originals for accessing the accuracy of the generated 3 D model. According to my findings, this method of insect model creation produced a more elaborate model than previous attempts made by the university lab. Existing problems are solvable with an upgrade in the photogrammetric guide’s technology. Theory • Photogrammetry art of overlapping photos to determine distances between points in order to create a 3 D model • Agisoftware uses Structure from Motion (SFM) to perform perspective geometry calculations • Perspective geometry the use of basic geometric properties of triangles to determine lengths Works Cited Concepts of Aerial Photography. (2016, September 01). Natural Resources Canada. Retrieved December 3, 2018, from https: //www. nrcan. gc. ca/earth-sciences/geomatics/satellite-imagery-air-photos/about-aerial-photography/9687 Dietrich, J. (2015, June 24). Agisoft Photoscan Crash Course (updated for version 1. 1. 6). Advanced Geographic Research. Retrieved December 3, 2018, from http: //adv-geo-research. blogspot. com/2015/06/photoscan-crash-course-v 1 -1. html Drone 2 Map for Arc. GIS Help. (n. d. ). Esri. Retrieved December 13, 2018, from http: //doc. arcgis. com/en/drone 2 map/process-andshare/vertical-reference. htm How Does Photogrammetry Work? (2018). Adam Technology. Retrieved December 3, 2018, from https: //www. adamtech. com. au/Blog/? p=102 Johannes L. Schonberger & Jan-Michael Frahm (2016). Structure-From-Motion Revisited [PDF file]. Chapel Hill, University of North Carolina. Retrieved December 3, 2018, from https: //demuc. de/papers/schoenberger 2016 sfm. pdf Johnson, Brittany [Brittany Johnson]. (2017, March 22). Agisoft Photoscan Workflow Tutorial [Video File]. Retrieved December 3, 2018, from https: //www. youtube. com/watch? v=Uny 9 n. Tr 22 go Juan (n. d. ). Agisoft Photo. Scan User Manual. SCRIBD. Retrieved from https: //www. scribd. com/document/302213721/Agisoft. Photo. Scan-User-Manual Knecht, Colin [Wood. Work. Web]. (2017, Sept 29). Make a Table Saw Circle Cutting Jig [Video File]. You. Tube. Retrieved December 3, 2018, from https: //www. youtube. com/watch? v=6 TCFzo. RVo 1 k Principles of Photogrammetry [PDF file]. (1993, March 31). University of Arizona: UA Science Lunar & Planetary Laboratory. Retrieved December 3, 2018, from https: //www. lpl. arizona. edu/hamilton/sites/lpl. arizona. edu. hamilton/files/courses/ptys 551/Principles_of_Photogrammetry. pdf Samsung Galaxy S 6. (2018). GSM Arena. Retrieved December 3, 2018, from https: //www. gsmarena. com/samsung_galaxy_s 66849. php Simple Method To Find T. D. C. (2018, July 14). MH Sub I, LLC dba Internet Brands. Retrieved December 3, 2018, from http: //www. rcuniverse. com/forum/glow-engines-114/101679 -simple-method-find-t-d-c-top-dead-center-2. html#&gid=1&pid=4 Spherical Coordinates. (2018, December 3). The Mysearch Website. Retrieved December 3, 2018, from http: //www. mysearch. org. uk/website 1/html/226. Spherical. html Support: Tips & Tricks. (n. d. ). Agisoft. Retrieved December 13, 2018, from http: //www. agisoft. com/support/tips-tricks/ Tutorial for Beginners: 3 D Model Reconstruction with Agisoft Photo. Scan 1. 4 [PDF file]. (2018) Agisoft. 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Retrieved December 3, 2018, from http: //dpi. lv/ Results Photogrammetry Guide Materials (1) Lazy Susan 12” diameter (1) Bike Phone Holder (2) Aluminum Slip-on Rail Fitting for 1” (1) Aluminum Round Tube 1/8” wall thickness, 1” OD, 3’ long Plywood ¾” thick Screws Feet (optional) Black paint (optional) Sealant (optional) Sandpaper 3 D Printing Materials (1) Filament spool (1) Resin Tray Procedure Step 1 Use boss laser to engrave 12” diameter circular platform with degree increments and cut platform out of plywood Step 4 Step 2 Mount platform to 12” diameter lazy Susan with appropriate screws Step 5 Step 3 Cicada Measurements Between Eyes Right Front Leg Between Front Knees End of Right Wing to Right Eye End of Left Wing to Left Eye Wasp 1 Measurements Width of Right Wing Between Tips of Wings Antenna Left Middle Leg Stinger to Right Wing Original (mm) 15 mm 10 mm 51 mm Model (mm) 17. 5 mm 4. 6 mm 11. 1 mm 58. 7 mm Percent Error 51 mm Original (mm) 7 mm 28 mm 7 mm 6 mm 29 mm 57. 5 mm Model (mm) 6. 1 mm 18. 5 mm 7. 4 mm 4. 6 mm 29 mm 12. 7% Percent Error 12. 9% 33. 9% 5. 7% 23. 3% 31. 4% Wasp 2 Measurements Width of Right Wing Between Front Leg Right Front Leg Left Front Leg Between Eyes Original (mm) 5 mm 13 mm 5 mm 5 mm Model (mm) 3. 5 mm 8. 8 mm 3. 5 mm 3. 7 mm 4. 3 mm Percent Error 30. 0% 32. 3% 30% 25% 14% 16. 7% 8. 0% 11. 0% 15. 1% Bend pipe into 14” ¾” diameter semicircle using a tubing roller (inner diameter measurement) Step 6 Conclusion Use hack saw to cut off 4” 5/12” (or the extra straight length of the pole left from rolling) so that the semicircle sits in rail-fitting with the same consistent innerradius 0 f 7” ¾” from platform across the entire semicircle. Step 7 Cut 12” x 18” plywood square out, mount lazy susan and platform, and mount rail fittings and arc to platform. Arc mounted off center to account for the phone camera being off center. Step 8 Screw on feet to bottom of the base and clean up for presentation purposes • • Put pictures into Agisoft and send through Batch Process. Clean up model in Meshmixer and 3 D print model. • Grid issue solved with sticky note and should be engrave next time Higher camera resolution would decrease percent error and increase detail Insects suspended on pin produce better alignments and larger insects scan better Lenses and transparent wings are harder to read by program • • A fully automatic guide is preferable Platform had unnecessary amount of increments and needed a grid to help software • Step 9 • Begin taking pictures (reference image in math section) θ=30° and ϕ=0°. Take picture at θ at increments of 10° from 0°to 90°AND ϕ at increments of 10° from 0°to 360°. Guide was serviceable and user-friendly for time and budget afforded Program wants to see through to base and create phony divots but can be fixed in Meshmixer 3 D prints are great for display and presentation