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Dark and Reflective Surfaces Leaving Holes

I’m new to Pix4Dmapper and the biggest issue I’m having is reflective surfaces, like windows, and dark surfaces, like asphalt and shadowy areas, leave big holes in the point cloud.

Is there a way to change the settings to increase the generated output on surfaces like these.
I’m not sure where to begin and can’t seem to find any how-to’s on the subject.

Thanks

Hi @ctwbim, I know what you mean, it is challenging to reconstruct areas like that as the same area/feature is captured differently on each image due to reflections.

If possible, try to adjust the flight plan and increase the overlap and decrease the flight height. We did some tests and saw, with senseFly Aeria X camera, the reconstruction of asphalt was optimal when using the 75/75% overlap and GSD between 2 cm and 2.5 cm.
It also helps to fly on a cloudy day.

As for the processing options. If you would simply like to generate more points, then you consider increasing the Point Cloud Densification option Minimum number of matches to 2. But keep in mind that this can generate a lot of noise.

If you want to make sure that the holes are not visible in the mesh and DSM, then you can consider adding surfaces. They can be treated as constraints and will will the holes in the mesh and the DSM.

I hope this helps!

Thanks for your suggestions.

We had done most of these with a 90% overlap with the same results. The parking stripes would show up but not he asphalt between. Adding a surface isn’t viable since we’re trying to capture the topography in a point cloud for further processing in other softwares.

I was hoping there was a setting like on our terrestrial laser scanner known as “dark point filtering” where you can set the luminance threshold to exclude. I was hoping there was something similar in the Mapper software.

I guess we’ll stick to flying on cloudy days for now.

Thanks again!

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