Creating 3D models of existing objects is easy with 3D scanners and photo-reconstruction software.
Popular and recommended:
- Trnio: An easy-to-use iOS app. Includes native Sketchfab and Facebook sharing.
- SmartMobileVision Scann3D: A free, easy-to-use, Android app. Includes native Sketchfab sharing
- Agisoft PhotoScan: High quality, commercial Windows and OS X desktop app. Includes native Sketchfab sharing.
- Autodesk ReCap 360: A free, Windows-based 30-day trial.