ucsd-compfab

Week 6.1 - 3d Scanning, and Photogrammetry

Agenda

• Artist of the Day
• Check in / get help on Small Object / Digital Double
• 3D Scanning
  • Intro
  • 3D Scanning Hands-On
• 3D Scans in Rhino
• Homework

Artist of the Day

Paul McCarthy

• White Snow
• Heigh-Ho, Heigh-Ho, I Mistrust Paul McCarthy’s Snow White Sculptures (But I’m Not Saying Don’t Go), The Stranger, Seattle, WA 2016.

3d Scanning

Intro

• Two main techniques: photogrammetry and LIDAR
  • Photogrammetry
  • LIDAR / 3d scanning (with laser)
    • Handheld scanner at Envision
• Examples of room scans (Twomey)
• Simple solution, phone/tablet apps.
  • Kiri, Polycam, Widar, etc. See Other scanning apps in References below.
  • Other approaches?
• Strengths and limitations of various approaches.

3d Scanning Hands-on

• Install Scaniverse https://scaniverse.com/
  • ten scanning tips for scaniverse
• Take turns with your neighbor scanning portraits.
• Use the tools in the app to crop the scan to an appropriate size/shape.
• Export to a file format and import into Rhinio.
  • Exports to Sketchfab, or to zip file.
  • Sketchfab https://sketchfab.com/

3D Scans in Rhino

Really just working with Meshes. Export from the scanning app as OBJ, PLY, or similar format.

Fixing Meshes

Mesh Repair Follow the detailed Scan, Cleanup, Remodel workflow described in the Rhino Whitepaper below ScanCleanupRemodel.pdf

Rhino Mesh Commands:

• MeshRepair contains many mesh repair tools in a single dialog.
• FillMeshHole attempts to fill all open holes in the mesh. To make it watertight.

Editing Meshes

• ReduceMesh simplifies the mesh. Reduces number of vertices and faces.
• Mesh Trim (Mesh -> Edit Tools -> Trim)
• Mesh Split (Mesh -> Edit Tools -> Split)
• Combine with other parts (solids, meshes, using extrude, boolean)

Homework

• HW Finish Exercise 6: Digital Double (DUE Thursday 11/7 End of Day) design and Fabricate
• HW Submit your Digital Sketchbook - Midterm Check In (DUE 11/12 end of day)

References

• Other Scanning Apps
  • Kiri Engine (iOS, Android and Web) three free exports per week
  • Polycam https://poly.cam - does both photogrammetry and LIDAR (iOS and Android)
  • Widar https://www.widar.io/ (iOS and Android) 5 scans per day
  • MagiScan https://magiscan.app/ (iOS and Android)
  • Scandy Pro https://www.scandy.co/apps/scandy-pro - can use the front facing LIDAR
  • Objy.app https://www.objy.app/ can use LIDAR (iOS only)
• Rhino Whitepaper on Scan, Cleanup, Remodel: ScanCleanupRemodel.pdf
  • ScanCleanupRemodel.zip
• Mesh Lab research grade mesh software. Implements many state of the art softwares.