3D footbridge modeling issues

[Ali_J]

Hello everyone,

I use 3DF Zephyr Lite and I want to create a 3D model of a metallic footbridge. We have several photos of each side of the stairs, railings, and deck. However, when we extracted a textured 3D model from the software, it was incomplete and there were disturbances in the model due to lighting and backgrounds in all the photos of the footbridge. My colleague suggested removing the background from the 2000 photos of the railings. Is removing the backgrounds the solution? Can you tell me what quality of photos is necessary for a large structure like a footbridge? I also attach the 3D model I found in the software, as well as some photos of the railings.

[cam3d]

Hi Ali_J This kind of subject is difficult for photogrammetry capture/processing, and for best results will need to use a different technology such as LiDAR.

Reasons it's difficult:

- Metallics and any other reflective surface materials will be viewed differently from different angles, meaning less consistency between images.
- Homogenous surfaces with very little surface detail mean Zephyr has fewer keypoints to latch on to.
- Repeating patterns can cause false positives with matching.

Image quality for successful capture would need to be near perfect, low ISO, fast shutter, wide DOF - Shoot on a still, cloudy, bright day. LiDAR is a much better option in my opinion, or a combination of both so that you get the benefit of mesh from lidar and texture from photogrammetry - Note: This kind of dual processing requires the full version of Zephyr.

[Ali_J]

Hello,
I am currently working on a large bridge. We have three dense point cloud models of the bridge, photographed with three different cameras and from different angles.
These models are not complete, for example, they are missing parts like the guardrails or the stairs. With the "Workspace Merge" feature, we can align these point clouds to create a complete 3D model. We need to purchase the full version of Zephyr for one month?

[cam3d]

Ali_J Yes you can purchase 3DF Zephyr for 30 days to use that function: https://www.3dflow.net/purchase-3df-zephyr-monthly/