Scale to real world size?

[antithing]

Is there a way to scale the finished mesh by a real-world object?

For example, in photoscan, we scan assets with a ruler / object of know size, and then use that to set the scale of the mesh.

Is this feature available in AliceVision/meshroom?

It would just need to be 👍
Select two 3d points.
Give a known size.
Scale the mesh.

[nmenu]

definitly a must have !
Ideally, inroduce GCPs to get the model in the right position, orientation, scale, etc and provide a report on the transformation. (the quality of the transformations (errors on each of the GCPs) used. )

In addition a great option is to let people add check points, the check points unlike control points do not participe in the model transformation, but you can see afterward what difference you have on those points. This gives a great ideal of the quality of your end results.
You guys are really doing a great job.

Please let me know if I can help on the documentation of the project, it will be my pleasure.
Kind Regards, Nicolas

[natowi]

@nmenu You are welcome to help with the Meshroom documentation (Meshroom #186)

[kauevestena]

Hello, I really want to help on this topic, i'm a student on Geodesy and Cartography, i have some knowledge...

so, how can I help?

[TrevorNewsome]

Is this something that is being considered? This would bring a fantastic improvement for modelling from aerial drone imagery which is what I use it for.

[natowi]

@TrevorNewsome Yes, as you can see from #154 and #67.
As a first step, #351 adds 2 methods for coordinate system transformation from #154 via SfMtransform.

[JulianGrayMunich]

I add support for this request. Nicolas described perfectly. Need a 3D least squares 7 parameter transformation on premarked GCP - my use is to create a 3D backdrop from drone or other imagery for use in deformation monitoring.visualisation.

[trenchant7]

is the function available yet to get measurements from the extracted mesh or calibration stages

[SpatialProf]

+1

I'd really like to see the ability to use [Ground] Control Points. Control points in arbitrary, Cartesian coordinates would be a great start. Control point with geographic (Lat/Long) and UTM (m) coordinates would be a great second step. Finally, GCP with a variety of projections used around the world would be brilliant.

It would also be great to use camera ephemeris (6-DOF) embedded in EXIF as a start (i.e. first approximations of exterior orientation for photo stations, or "camera poses" as they're sometimes known). The next step would be the ability to import 6DOF ephemeris as ASCII in a wide variety of coordinates/projections, as with GCP.

If any of this has already been done please point me in the right direction!

Many thanks.

[natowi]

At the moment only scaling based on CCTAG is implemented #695 but not yet available in the release.
(The resources of the main Meshroom devs are limited, so that´s all for now)

@SpatialProf are you interested in contributing the features you mentioned?

[SpatialProf]

My coding skills are rusty in the extreme! However, I'd be happy to provide advice from a geodesy perspective, if there is some means of doing so?

[natowi]

@SpatialProf you are welcome to add your ideas to the discussion here alicevision/Meshroom#705 You could also write up a draft here https://github.com/alicevision/meshroom/wiki/Good-first-contributions#gcp-support-

At the moment we do not have any selection tools in the gui (->Meshroom). Instead of the reference points provided by cctag, points provided by the gui could be used to scale a model.

[natowi]

https://github.com/alicevision/meshroom/wiki/CCTAG-scaling

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[rossoe]

+1 working in GIS field most of the time, this would be an extremely useful feature. Having done similar work in Agisoft products where it automatically georeferences the meshes based on geo data already stored within drone images, it's then ready for import into GIS applications. It would be a huge win if Meshroom could do something similar.

[natowi]

alicevision/Meshroom#1539 and #1069