scanning a pictish cross enquiry

[marbles]

Hello,

Brand new to the forum. My first question.

I have a Pictish carved stone to scan and make a 3d printed reproduction copy. It’s in a museum and is currently exhibited vertically on the wall. The slab is 540 x 320 x 40mm. I

I would normally do a photogrammetry capture but it’s in the busy part of the museum and I’m not allowed to use lighting or remove the carving to put on a turntable. I don’t have an image of the part but have attached a surrogate image of similar stone and carving detail (shallow fine lines). I have a Revopoint Range 1 and a Revopoint Mini 1. I am going to have to scan handheld using these.

My question is about capture and processing workflow for this project to try and get the most detail from the available tech I have.
Q:I wonder if anyone has advice about how to use the Revopoint Range and the Revopoint Mini in combination to get the best quality scan from this equipment?

My plan was do one complete capture with the Revopoint Range. Then do separate scans use the Revopoint Mini to capture details and merge together. However I have tried with some samples to merge scans from both scanners of one object but even using 4 markers in the merge function the results were somewhat unsatisfactory.

The Revopoint Mini 1 is fiendish in handheld mode but could be useful for some key details which I can cut out of the Range scan and insert. It will be challenging.


Q: I wondered if I should add markers? such as Blu Tac cones to help with alignment and registration issues (that’s if I’m allowed to stick Blue Tac to the artefact.

Any advice welcome.

[greenskynet]

for scanning such big and heavy object, there is no need to turntable, because if you use a turntable, the object must be completely fixes on the table, and fixing heavy objects on a rotary table is not practical, specially if your rotary table has more than one axis.

Revopoint is not the best choice if you want to capture the small details of the object.

usually stationary scanners, and SLS scanners yield more details on the scans.
Handheld scanner have lower resolution cameras for fast processing, so there is no expectation for high details on the scans by a handheld scanner.

if you can't prepare good lighting for photo capturing, then Photogrammetry is not the best option to this project.

if your object is texture-less (for example if most of its surface is flat), and you can't use markers, then you need a two step strategy for this scan:
1- first scan it with a big FOV, and try to capture its entire surface in one scan shot. we use this scan for a base for alignment.
2- scan it section by section, with a small FOV, to capture all details. then use the first scan as a reference for alignment of the small scans, based on their mesh geometry.

also if you can place witness object on your main object, it help for alignment. you can stick markers on the witness object and just place it on the main object, but no need to stick it to the object.

if you need very high detail scans, you may be interested in DIY SLS scanners too.
The DIY SLS Scanner allow you to scan objects in different FOV, and align scans automatically, and it is one of the best for capturing highest details on your scans.
These two stone scans were captured with my DIY SLS Scanner:

Also the following video is a sample for scanning an object, section by section, using my DIY SLS Scanner. The alignment was done automatically using markers.
https://www.youtube.com/watch?v=fm-WT8g8_k0