Jun 26, 2025
Workflow for Marking and Exporting Lithic Scar Orientations Using Geomagic Wrap and Rhino
- Zhi Ye1,
- Sam Lin2,
- Ben Marwick3
- 1Institute of Vertebrate Paleontology and Paleoanthropology;
- 2University of Wollongong;
- 3University of Washington
- Zhi Ye: This protocol manuscript was written by Zhi Ye;
- Sam Lin: This method was developed by Sam Lin, who provided the methodological framework for applying orientation analysis to the study of flake scar organization. He also contributed to the revision of this manuscript;
- Ben Marwick: This protocol manuscript was revised by Ben Marwick
Protocol Citation: Zhi Ye, Sam Lin, Ben Marwick 2025. Workflow for Marking and Exporting Lithic Scar Orientations Using Geomagic Wrap and Rhino. protocols.io https://dx.doi.org/10.17504/protocols.io.rm7vz1dj8lx1/v1
Manuscript citation:
Lin S C, Clarkson C, Julianto I M A, et al. A new method for quantifying flake scar organisation on cores using orientation statistics[J]. Journal of Archaeological Science, 2024, 167: 105998.
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: April 29, 2025
Last Modified: June 26, 2025
Protocol Integer ID: 190826
Keywords: Lithic technology, Quantitative methods, Three-dimensional analysis, Flake scar patterning, exporting lithic scar orientation, flake scar orientations from 3d scanned model, extracting flake scar orientation, objective analysis of scar orientation, scar vector annotation, scar vector coordinate, scar orientation, scar vector, standardization of scar vector, set of scar vector coordinate, flake scars on core, flake scar, rhino understanding, archaeological lithic assemblage, 3d scanned model, orientation analysis, geomagic wrap, ready for orientation analysis, spatial alignment, using geomagic wrap, rhino understanding the organization, rhino, vector coordinate data, export of vector coordinate data
Abstract
Understanding the organization of flake scars on core is crucial for interpreting core reduction strategies. Here, we present a protocol for recording and extracting flake scar orientations from 3D scanned models of cores. Using Geomagic Wrap and Rhino 8, the method involves scar vector annotation, generation of a best-fit plane, spatial alignment and standardization of scar vectors, and the export of vector coordinate data. The resulting set of scar vector coordinates is ready for orientation analysis in R. Developed by Sam Lin et al., this protocol enables reproducible and objective analysis of scar orientations across archaeological lithic assemblages.
Guidelines
To ensure clarity and consistency throughout the protocol, the following typographical conventions are used:
(1) Software features and tools are written in bold, e.g. Feature;
(2) <Keyboard keys> are enclosed in <angle brackets>, e.g. <Del> or <Ctrl>;
(3) Software operations and workflows are indicated using arrow notation, e.g. Features > Plane > Best Fit;
(4) Commands typed into the keyboard or command line are written in [square brackets], e.g. [what].
Troubleshooting
Acquire 3D Scan of cores
Digitize the core using a 3D laser scanner
Use a structured-light or laser scanner (e.g., Artec Spider, etc.)
Post-process the raw scan
Use the scanner’s native software (e.g., Artec Studio, etc.) or compatible 3D processing tools
In Artec Studio, the post-process usually includes:
- Erasing Tool-to remove unnecessary geometry
- Global Registration-to align all scan frames into a coherent point cloud
- Fusion-to merge the frames into a single mesh
- Optional: Small Object Filter or Outlier Removal and Hole Filling
Export the 3D model
Save the final mesh as an STL (.stl) or OBJ (.obj) file
Mark Scar Orientations in Geomagic Wrap
Open the model in Geomagic Wrap
Open Geomagic Wrap
Select: File > Open, and load your .stl file
- Set units as needed (e.g., centimeters)
- Optional: Run Mesh Doctor to repair the mesh
After loading your .stl file, the interface will appear as shown below. For demonstration purposes, we used a standardized core model (Lin et al.,2024) here
Snapshot of configured workscape, with labelled positions of the basic tools and functions which will be needed in the following steps
Annotate line features on the core
Select: Features > Line > 2 Points
Snapshot of step 5.1
Click on the model to mark: flake scar origin and flake scar termination
- For incomplete scars lacking identifiable origins, terminations, or both, first determine the flaking axis. Then, mark the proximal-most and distal-most points along this axis
Snapshot of step 5.2-5.3
Click Apply to save the current line
Click Next to begin annotating the next flake scar
Snapshot of step 5.4
Repeat the steps: Mark points → Apply → Next, until all flake scar vectors are completed
Tips:
- Rotate: Hold scroll wheel and drag
- Zoom: Use scroll wheel
Click OK to save line features
Snapshot of step 5.6
Create best-fit plane
Select: Features > Plane > Best Fit
Snapshot of step 6.1
<Right-click> on the model and choose: Select All
- After selecting Select All, the model will turn red to indicate that it is fully selected
Snapshot of step 6.2
In the Graphic-Dialog, click Apply, then click OK
Snapshot of step 6.3
Export the annotated model
Select: File > Save As
Choose a location to save the work and set format to .igs
Snapshot of step 7.2
Align Line Features in Rhino
Import the model in Rhino
Open Rhino 8
Select: File > Open, and load your .igs file
- The Rhino interface displays four viewports. You can enlarge a preferred view (e.g., Perspective) and right-click to rotate the model
After loading your .igs file, the interface will appear as shown below
- Commands can be entered via buttons or directly in the Command dialog — the latter is often faster
- Enable Osnap (or type [Osnap] in the command line) to assist with precise point selection
Snapshot of configured workscape, with labelled positions of the basic tools and functions which will be needed in the following steps
Orient the model‘s best-fit plane using three points
Left-click and drag to select the line and plane features
- Selected items will appear yellow
- Be sure all features are selected
In the command line, type [Orient3Pt]→ press <Enter>
Snapshot of step 9.1-9.2
On the model’s best-fit plane, click three reference points: Reference Point 1, Point 2, Point 3
Snapshot of step 9.3
In the command line, input coordinates for the target plane (we aim to align with the XY plane):
type [0,0,0]→ press [Enter]
type [1,0,0]→ press [Enter]
type [0,1,0]→ press [Enter]
Snapshot of step 9.4
Move the longest line to X=0 and Y=0
In the command line, type [EvaluatePt]→ press <Enter>→click the starting point of the longest line:
The XYZ coordinates will appear. Copy the Z-coordinate
Snapshot of step 10.1
Type [Move]→ press <Enter>→click the starting point of the longest line
Snapshot of step 10.2-10.3
In the command line, type [0,0,Z-Coordinate of the starting point]→ press [Enter]
- This ensures that the best-fit plane remains aligned with XY plane
Export coordinate data
Select all the lines→In the command line, type [What]→ press <Enter>
Snapshot of step 11.1-11.2
In the pop-up dialog, File > Save As
Choose a location to save the coordinates as a .txt file
Snapshot of step 11.3
Now you are ready to analyse the coordinates in R
Protocol references
Lin S C, Clarkson C, Julianto I M A, et al. A new method for quantifying flake scar organisation on cores using orientation statistics[J]. Journal of Archaeological Science, 2024, 167: 105998.
Acknowledgements
I thank Ben Marwick for suggesting that this protocol be made publicly available, which helps researchers quickly acquire the skills needed to complete this type of work.
I also thank Sam Lin for his repeated and valuable feedback, which greatly improved the clarity and conciseness of the protocol.