3 ms·

> the object was on a rotating platform Isn't a static-object-rotating-camera basically a requirement for photogrammetry?

Mashimo 2y ago
Why would that make a difference?
- SequoiaHope 2y ago
  Photogrammetry generally assumes a fully static scene. If there are static parts of the scene which the camera can see and also rotating parts, the algorithm may struggle to properly match features between images.
  - Mashimo 2y ago
    i think it's common to have dots on the rotating disk where the object is placed on.
    - SequoiaHope 2y ago
      Sure, but if the background has a lot of features it will still confuse the algorithm unless it has some special settings for ignoring the background.
- deleted 2y ago
  [deleted]
- addandsubtract 2y ago
  The OC mentioned "static lighting". If they meant static, while the platform was spinning, then the lighting would be inconsistent, because the object would change lighting with each photo. You would have to fix the lighting to the platform to spin with the object, while taking the pictures to get consistent lighting.
  - geuis 2y ago
    I think you just nailed why I have been having a hard time with my photo set. It's the lighting. Well crap, because I don't have access to the statue or studio again. Thanks for the tip.
    - ryandamm 2y ago
      You could try generating per-view depth maps, going to a point cloud and meshing from there. (I suspect splats may reduce your accuracy as an intermediate.) I’m not aware of a fully-baked workflow for that — though it may exist. The first step has gotten really good: the recent single-shot AI models for depth are pretty visually impressive (I don’t know about metric accuracy). The ones I’m aware of are DUST3R and the newer MAST3R: https://github.com/naver/dust3r https://github.com/naver/dust3r https://github.com/naver/mast3r https://github.com/naver/mast3r Good luck!
jdietrich 2y ago
No. For small objects, it is typical to use a turntable to rotate the object; there are a number of commercial and DIY turntables with an automated motion system that can trigger the shutter after a specified degree of rotation.

Mashimo 2y ago

Why would that make a difference?

SequoiaHope 2y ago
Photogrammetry generally assumes a fully static scene. If there are static parts of the scene which the camera can see and also rotating parts, the algorithm may struggle to properly match features between images.
- Mashimo 2y ago
  i think it's common to have dots on the rotating disk where the object is placed on.
  - SequoiaHope 2y ago
    Sure, but if the background has a lot of features it will still confuse the algorithm unless it has some special settings for ignoring the background.
deleted 2y ago
[deleted]
addandsubtract 2y ago
The OC mentioned "static lighting". If they meant static, while the platform was spinning, then the lighting would be inconsistent, because the object would change lighting with each photo. You would have to fix the lighting to the platform to spin with the object, while taking the pictures to get consistent lighting.
- geuis 2y ago
  I think you just nailed why I have been having a hard time with my photo set. It's the lighting. Well crap, because I don't have access to the statue or studio again. Thanks for the tip.
  - ryandamm 2y ago
    You could try generating per-view depth maps, going to a point cloud and meshing from there. (I suspect splats may reduce your accuracy as an intermediate.) I’m not aware of a fully-baked workflow for that — though it may exist. The first step has gotten really good: the recent single-shot AI models for depth are pretty visually impressive (I don’t know about metric accuracy). The ones I’m aware of are DUST3R and the newer MAST3R: https://github.com/naver/dust3r https://github.com/naver/dust3r https://github.com/naver/mast3r https://github.com/naver/mast3r Good luck!

jdietrich 2y ago

No. For small objects, it is typical to use a turntable to rotate the object; there are a number of commercial and DIY turntables with an automated motion system that can trigger the shutter after a specified degree of rotation.