3D modeling of plants with realsense : is it possible, is it good ?

[DFour]

Hello,

I would like to know if some people already use realsense cameras to make 3D modeling of plants ? The idea is to create a point cloud by rotating the plant, but we would need a good precision. What can we expect for a plant at a distance of one meter for depth precision ?

Thank you in advance.

[MartyG]

At a distance of 1 m, you should be able to get accurate depth readings, as the depth accuracy does not start drifting noticably until around 3 meters onward.

I recall a case in which tomatoes in a greenhouse were scanned. That is the only example I know of where depth-scans of plants have been taken.

https://forums.intel.com/s/question/0D50P0000490XlmSAE/depth-cloud-precision-intel-d415?language=en_US

You may get a higher quality scan if, instead of rotating the plant, you place multiple cameras in a circle around the plant, take a point cloud capture from each and then combine the multiple point clouds together into a single 360 degree model. If you place the cameras so their fields of vision overlap, you get better detail because there is redundancy in the data because of more than one camera observing the same area. The more cameras you have, the less blind-spots there are in the scanning process.

[DFour]

Hi MartyG,

Thank you for the informations. That looks very interesting.

What "depth accuracy" would you expect at one meter ?

Do you mean there are still software functions that take advantage of a hardware configuration consisting of multiple cameras ? I thought a rotating system with a very good angular accuracy and multiple captures, with small angles, let say every 5 degrees, should be better than only 4 ou 5 cameras.

[MartyG]

The best-case scenario for accuracy over distance is illustrated in Intel's excellent camera tuning guide. On the graph below, with represents 'RMS error' over distance, the lower curve is the D415 and the upper curve is the D435. Please left-click on the image to view it in full size.

https://realsense.intel.com/wp-content/uploads/sites/63/BKM-For-Tuning-D435-and-D415-Cameras-Webinar_Rev3.pdf?language=en_US

Rotating the plant with a single camera is certainly an alternative option to using multiple cameras. Below is a list of some 3D modeling packages that are compatible with the 400 Series cameras.

LIPS 3D

https://www.youtube.com/watch?v=N14Pi6z-MkE

Dot3D Scan

https://forums.intel.com/s/question/0D50P0000490YKlSAM/dotproduct-announces-dot3d-scan-support-for-realsense-400-series

RecFusion

https://www.recfusion.net/index.php/en/?utm_source=intelrealsense_website&utm_medium=callout&utm_campaign=partner_page