TITLE: ReViBE: protocol for Refit Visualisation of lithic reduction sequences using the Blender Engine
AUTHORS: Javier Sánchez-Martínez, Katia Calmet, Jorge Martínez-Moreno, Xavier Roda Gilabert

[DESCRIPTION]
Here, we introduce ReViBE, a step-by-step protocol for visualising lithic refits through the utilisation of imaging technologies, photogrammetry, 3D modelling and Blender animation software. Lithic refittings represent high-resolution temporal sequences that shed light in cognitive, organisational and taphonomic aspects of the archaeological record, and have remained integral for the archaeological science since its inception. Despite their popularity, little work has been focused on the representation of refittings, traditionally undertaken through photography and archaeological drawing. While the use of these recording tools are widespread in the discipline, their application in refittings has limitations, as they fail to capture the three-dimensional nature of lithic reduction.

Our ReViBE protocol addresses this issue through a step-by-step procedure that combines the creation of 3D models in refittings and their animation, allowing a more dynamic visualization of lithic reduction sequences in high definition. The protocol consists of three main phases in which we explain how to perform photogrammetry on the refitted artifacts, create three-dimensional models from the captured images (e.g., Photoscan/Metashape), and finally, generate animation by reconstructing the motion of each individual piece in a temporal sequence (e.g., Blender).

Furthermore, we suggest incorporating protocols employing 3D modelling to aid in the digital visualization of material culture, enhancing the accessibility and study of archaeological heritage.



Content:

Part 1 – Initial remarks and set up preparation
Part 2 – Obtention of 3D models using photogrammetry 
Part 3 – Converting images to 3D 
Part 4 – Creation of animation sequences using Blender
Supplementary video


 



[GUIDELINES]
Typographical emphasis used in the protocol:

References to materials and software used in italics, e.g. Helicon Focus
Software features in bold, e.g. Align Photos
Computational workflows linked by angle brackets (>), e.g. Workflow > Build Mesh
Keyboard buttons indicated by angle markers (< >), e.g. <Right-Click >

This protocol was developed using Helicon Remote© 4.4.4, Agisoft Photoscan© 1.5.2 and Blender© 3.6. Different versions of the software will present slightly differing interfaces, but the general workflow is still the same. 

The last section of the protocol contains a video with an extended overview of the whole process.

[STEPS]
SECTION: Part 1 - Initial remarks and set up preparation
1. Place the camera on a tripod (ideally with a zoom lens with a focal length between 35mm and 80mm). Do not use an autofocus lens.
SECTION: Part 1 - Initial remarks and set up preparation
4. With 3 light sources, create diffused lighting from both sides and above. Try to avoid large shadows on the background surface and on the piece.
SECTION: Part 1 - Initial remarks and set up preparation
5. Shoot with the camera connected to a laptop running Helicon Remote © or any other remote software.

 
SECTION: Part 1 - Initial remarks and set up preparation
2. Place the artefact in a light box or, if this is not available, on a plain coloured background.
SECTION: Part 1 - Initial remarks and set up preparation
3. Place the artefact on a turntable within the workspace.

 
SECTION: Part 1 - Initial remarks and set up preparation
3.2. Use a Photogrammetric scale marker to scale the images afterwards. Three free versions of the photogrammetric scale can be downloaded at this link  (Porter, Roussel & Soressi, 2016a; Porter, Roussel & Soressi, 2016b).

 
SECTION: Part 1 - Initial remarks and set up preparation
3.1. 
 

SECTION: Part 1 - Initial remarks and set up preparation
3.3. If the artefact will not stand due to its irregular shape, use an appropriate amount of modelling clay wrapped in plastic wrap to create a modifiable support surface. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
107. 
107. 
SECTION: Part 1 - Initial remarks and set up preparation
107. 
107. 
107. 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
6. Open Helicon Remote . 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
7. <Click> Toggle Live view for seeing what is on the frame.
SECTION: Part 2 - Obtention of 3D models using photogrammetry
8. Configure Helicon Remote Software

Set the camera on the Camera settings following the next parameters:

F- number between 2 and 1.3 
Aperture between 8 and 14
100 ISO  
SECTION: Part 2 - Obtention of 3D models using photogrammetry
9. <Click> on Take picture on the top toolbar. 

 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
10. Move the artefact 10 degrees on the turntable.
SECTION: Part 2 - Obtention of 3D models using photogrammetry
11. Take another picture.
SECTION: Part 2 - Obtention of 3D models using photogrammetry
12. Repeat steps   ,   ,   to capture all the 360º.
SECTION: Part 2 - Obtention of 3D models using photogrammetry
13. Change the position of the camera to a high-angle.

 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
14. Repeat steps   ,   ,   from this angle.
SECTION: Part 2 - Obtention of 3D models using photogrammetry
15. Return the camera to a frontal angle and turn the artefact upside down.

 
SECTION: Part 2 - Obtention of 3D models using photogrammetry
16. Repeat steps  ,   ,   with the artefact upside down.
SECTION: Part 2 - Obtention of 3D models using photogrammetry
17. Repeat steps    and    .
SECTION: Part 3 - Converting images to 3D
18. Opening and configuring the Agisoft Photoscan© Software

 

Legend:

1. Workspace, to organise.  
2. Markers to scale the artefact.
3. Scale bars to introduce the scale interval.
4. Model view, to see the development of the artefact.
5. Photo section where all the photos are separated. Masks can be applied in this area.
6. Freeform selection tool.
7. Markers.
8. Update, to apply the measurements to the scale bars.

 
In the left part of the screen, go to Workspace and tap <Right-click> on the mouse > Add Chunk.


 
SECTION: Part 3 - Converting images to 3D
19. Go to the pictures folder on your computer and drop all the photos with the artefact in a single position, with the front angle and the high angle.

 
SECTION: Part 3 - Converting images to 3D
20. Create a mask.

Go to the Photos section and open one. Use the magic wand to select the background. <Right-click> and select Add Selection. Do this for each photo.

 
SECTION: Part 3 - Converting images to 3D
21. Return to the model view.
SECTION: Part 3 - Converting images to 3D
22. Select Workflow on the toolbar and <Click> on Align photos.

 
SECTION: Part 3 - Converting images to 3D
23. In the pop-up window, select Accuracy > Medium and Pair preselection > Disabled.
SECTION: Part 3 - Converting images to 3D
24. Select Workflow on the toolbar again and <Click> on  Build dense cloud.
SECTION: Part 3 - Converting images to 3D
25. On the pop-up window select Quality > Medium.

 
SECTION: Part 3 - Converting images to 3D
26. Select Workflow > Build Mesh. 

SECTION: Part 3 - Converting images to 3D
27. In the following pop-up window leave the default parameters and <Click> the OK button.

 
SECTION: Part 3 - Converting images to 3D
28. Select Workflow > Build Texture.
SECTION: Part 3 - Converting images to 3D
29. In the following pop-up window leave the default parameters and<Click> the OK button.

 
SECTION: Part 3 - Converting images to 3D
30. Clean up the artefact, use the freeform selection tool and draw over the parts that do not belong to the artefact, and press <DELETE> on your keyboard.
SECTION: Part 3 - Converting images to 3D
31. Add Chunk 2 on the Workspace.
SECTION: Part 3 - Converting images to 3D
32. In the Photos panel, move all the photos that are left in the pictures folder with the artefact to the other position.
SECTION: Part 3 - Converting images to 3D
33. Repeat   ,  ,  ,  ,  , .

SECTION: Part 3 - Converting images to 3D
34. Open Chunk 1 and go to the Photos pane.
SECTION: Part 3 - Converting images to 3D
35. Open one of the photos from the high angle where the Photogrammetric scale marker is visible.
SECTION: Part 3 - Converting images to 3D
36. Using the marker tool, <Right-click> on one of the targets and select Create Marker.

 
SECTION: Part 3 - Converting images to 3D
37. Repeat    on each reference target in the image. 


<Right-click> on the target > place marker > choose the point that matches the one in the image above. 
SECTION: Part 3 - Converting images to 3D
38. Repeat    ,    in every high-angle photo.
SECTION: Part 3 - Converting images to 3D
39. On the Reference menu, go to the Makers section and select two points that are parallel to each  other, <Right-click> and select create scale bar.
SECTION: Part 3 - Converting images to 3D
40. On the scale bar, enter the distance between the targets according to the distance in real life.


 


 
SECTION: Part 3 - Converting images to 3D
41. <Click> the Update icon and return to the model.

 
SECTION: Part 3 - Converting images to 3D
42. Repeat  ,  ,  ,   on chunk 2.
SECTION: Part 3 - Converting images to 3D
43. Now go to Workflow  > Align Chunks.
SECTION: Part 3 - Converting images to 3D
44. In the pop-up window, select the two chunks and leave all the parameters as default.
SECTION: Part 3 - Converting images to 3D
45. Workflow > merge chunks.
SECTION: Part 3 - Converting images to 3D
46. In the pop-up window, select the two chunks and choose Merge models.

 
 
SECTION: Part 3 - Converting images to 3D
47. Export
 
File > Export      Model > Export OBJ/FBX/KMZ…> OK 



SECTION: Part 3 - Converting images to 3D
22.1. 
 

 
SECTION: Part 3 - Converting images to 3D
29.1. 
 

 
SECTION: Part 4- Creating animated sequences using Blender
48. Blender is a flexible tool with many possibilities that allows the creation of animation sequences using the 3D models previously obtained by photogrammetry. Here we explain the different steps that should be followed up to create core reduction animation sequences.


Open Blender >  Select the General option at the first menu.

 
Legend:

1. 3D cursor (for moving objects arround the workspace).
2. Rotate tool (to rotate the object).
3. 3D view of the workspace.
4. Timeline (display of the movements in time by keyframes).
5. Viewport shading (view of the object with the texture).
6. Toggle the camera view. 
7. Render Properties.
8. Output Properties.
9. Object Properties.
10. Scene collection (space with a list of all the objects).
11. Header (where the object mode options can be found).
SECTION: Part 4- Creating animated sequences using Blender
49. Delete the cube by default,  <Click> on the cube and press <DELETE>
SECTION: Part 4- Creating animated sequences using Blender
50. File > Import > Obj. and browse for the object in the computer folder.
SECTION: Part 4- Creating animated sequences using Blender
51. Place all the artefacts on the workspace.

<Click> on one of the artefacts.
SECTION: Part 4- Creating animated sequences using Blender
52. <Click> on the viewport shading to see the object with the texture.
SECTION: Part 4- Creating animated sequences using Blender
53. Go to object on the Header > Set Origin > Origin to centre of mass (surface).
SECTION: Part 4- Creating animated sequences using Blender
54. To move objects press  <G> on the keyboard and move the mouse to position the object. To change the position more precisely go to the object properties. <Right-click> to set.
SECTION: Part 4- Creating animated sequences using Blender
55. To rescale objects, <Click> on the object in the workspace, press<S> and move the mouse in the object properties.
SECTION: Part 4- Creating animated sequences using Blender
56. To rotate the object, select the rotate tool and move the mouse on the axis you want to rotate or in the object properties panel.
SECTION: Part 4- Creating animated sequences using Blender
57. Repeat steps   ,   .   .   for each object one by one.

 
SECTION: Part 4- Creating animated sequences using Blender
58. Make the set up

Go to the Header > Add and <Click> on Camera. 
SECTION: Part 4- Creating animated sequences using Blender
59. Select the camera by clicking above it and press <G> on the keyboard, move the mouse, and move the camera until you have the object in the frame.
SECTION: Part 4- Creating animated sequences using Blender
60. <Click> on Toggle the camera view and see what’s in the frame.
SECTION: Part 4- Creating animated sequences using Blender
61. Adjust the frame, press <G>, and move the mouse, until you have the objects in the frame.
SECTION: Part 4- Creating animated sequences using Blender
62. Go to the Header > Add > Light > Point.
SECTION: Part 4- Creating animated sequences using Blender
63. Place 3 lights and create a standard 3 point lighting, one light behind the object and two lights from the sides of the camera.

 
Legend:

1. Artefacts/objects.
2. Camera.
3. Light point.
SECTION: Part 4- Creating animated sequences using Blender
64. Animation

Select Auto Keying on the Timeline to capture a keyframe every time an object moves.

 
SECTION: Part 4- Creating animated sequences using Blender
68. Move the bar on  the timeline to the second the action starts. 
SECTION: Part 4- Creating animated sequences using Blender
66. <Click> and drag the object you want to move to the first position.
SECTION: Part 4- Creating animated sequences using Blender
65. Drag the bar on the timeline to the second you want the object's first action to end.
SECTION: Part 4- Creating animated sequences using Blender
67. Place the object where the object's action ends, then <Click> to fix it.

 
SECTION: Part 4- Creating animated sequences using Blender
69. To rotate the object, set it to the second in which the object has not changed its position, move the bar on the Timeline to the second in which the rotation will end.
SECTION: Part 4- Creating animated sequences using Blender
70. Drag the 3D cursor over the object you want to rotate.
SECTION: Part 4- Creating animated sequences using Blender
71. Use the Rotate tool and apply the rotation at the second the movement ends on the Timeline.

 
SECTION: Part 4- Creating animated sequences using Blender
72. Repeat steps  ,   ,   ,   for each object.
SECTION: Part 4- Creating animated sequences using Blender
73. Render

Delimit the timeline where it says Start/End. Leave a few seconds at the end of the animation.
SECTION: Part 4- Creating animated sequences using Blender
74. Go to the Rendering tab.
SECTION: Part 4- Creating animated sequences using Blender
75. Output properties > output > name of the animation and where it's saved (folder) > Format File > FFmpeg video  > Colour profile RGB > Encoding > container > MPEG-4 >  Video > H264 > Lossless > Good.
SECTION: Part 4- Creating animated sequences using Blender
76. Render Properties  > Scene > Render Engine and change it to Cycles.
SECTION: Part 4- Creating animated sequences using Blender
77. Render Properties > Film > Transparent.
SECTION: Part 4- Creating animated sequences using Blender
78. Go to the Render tab (not rendering) > render animation.

 
There are several export options for this software, depending on how you want to use it and how quickly you can reproduce it on your device. You can also capture still images for editing in other programs, such as Adobe Photoshop, or for uploading to a website.

 

SECTION: Part 4- Creating animated sequences using Blender
51.1. 
 

SECTION: Part 4- Creating animated sequences using Blender
63.1. You can add another light to backfill.
SECTION: Part 4- Creating animated sequences using Blender
72.1. 
 

SECTION: Part 4- Creating animated sequences using Blender
72.2. 
 

SECTION: Part 4- Creating animated sequences using Blender
72.3. 
 

SECTION: Supplementary video
79. The video included in this section shows a detailed step-by-step process following the procedure explained in this protocol. Sample materials to ensure reproducibility of the method are available from this link.