Buildings


#1

Hi All,
In the process of exploring ODM, I am trying to compare orthophotos of ODM and another paid software.
I found that ODM shows the buildings with their side views too and that is making them wavy and distorted.

Earlier I tried with --fast-orthophoto but the waviness increased. So, I removed it and started experimenting with different variables and their combinations. Below are the pics of ODM and other software -

ODM:

Other:

I am using “docker run -it rm …” and passed following arguments:
–orthophoto-resolution 10.0
–resize-to 1350
–mesh-octree-depth 4
–min-num-features 16000
–time
Others kept as default.

Could someone help me explain why this occurs and …can this be rectified only by identifying better combination of argument values or any other processes?

Thank you.


#2

Hi @garlac,

I think the discussion Roof Utilities Distortion is related.
You can try to increase --mesh-octree-depth value to 10, but it will not be as good as you would like. But please let us know if this parameter improved your orthophoto in urban areas.

Regards!


#3

Thank you @jgrocha.
I increased the --mesh-octree-depth to 12 and found that the tilt of the buildings and side views got corrected.
But the building roofs have become wavy.

Also, as suggested by @smathermather-cm in one of the discussion, on reducing the --mesh-octree-depth to 6 the roofs were getting straight but the tilt and side views have come back.
Please find below the screenshot with increased octree depth:

Screenshot%20from%202018-08-24%2011-06-16
The parameters used were:
mesh-solver-divide: 12, mesh-octree-depth: 12, min-num-features: 16000, resize-to: -1, texturing-skip-hole-filling: true, orthophoto-resolution: 80, mesh-size: 1000000, use-exif: true, pmvs-wsize: 8, texturing-data-term: area, crop: 0, opensfm-depthmap-resolution: 960, opensfm-depthmap-method: BRUTE_FORCE

I will further try using pmvs to build point cloud and see if it improves the orthophoto.


#4

Sadly, short the release of our new code, none of this will get any better. As soon as we have a timeline for release, we will announce it!


#5

Thank you @smathermather-cm. Will wait for the new release.

I am digging into the code and in the process found that ODM uses generated mesh( odm_textured_model_geo.obj) as input to odm_orthophoto process whereas Pix4D uses point cloud(PC) to generate orthophoto.
Not sure whether changing that improves the orthophoto…

Btw, excited to read this : https://smathermather.com/2018/07/12/upcoming-improvements-to-opendronemap-better-everything/

Thank you.


#6

Release is imminent! Should be on master in the next few days…