Relight outputs to generate 3D Wireframes?

[Aaron Graham]

Has anyone tried to generate wireframe models from the Relight data at all? I saw one topographical output consistently appearing and it made me wonder if this was something that already exists or could be adapted.

[cdschroer]

From a single camera point of view (which is what we have with RTI data sets) we can't properly create a 3D surface.  We can create a normal map and other maps - from that 1 camera point of view and a series of known lighting positions.  While there are approaches to do this, (create 3D from RTI data, or from the produced normal maps) an error accumulates when the normals are turned into a mesh.  There are many technical papers about this going back over a decade.  Sometimes this is referred to as the "potato chip" effect, because the mesh is warped, like a potato chip, from the accumulated error.

If you need a mesh - we recommend using photogrammetry.  You can shoot RTI and photogrammetry of the same area, and register the RTI to the photogrammetry data. There are some advantages to that, though there are not currently tools that we know of that can take full advantage of such integrated data sets.  

There's a recorded talk about combining RTi and photogrammetry from the Symposium we co-hosted at the Met back in 2017.  It's Mark Mudges talk on Day 1 in the afternoon

https://www.metmuseum.org/about-the-met/conservation-and-scientific-research/projects/rti-symposium/day-1-pm -  All the talks are listed for each session, and what time they start within the video.  This one starts at 1:11:50

 

All the recordings from the 2 day event can be found here:

https://www.metmuseum.org/about-the-met/conservation-and-scientific-research/projects/rti-symposium

 

Carla

[Aaron Graham]

Thank you for this guidance and the resources!