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How can I generate the surface of a lake in PIX4D?

Hi everyone!
I have a surface with a lake whose water is really homogenous, so PIX4D can’t find enough points to generate the point cloud and the triangle mesh of the water.
Does anyone knows how to modify the images to generate some points for the program?Or another suitable solution?

It’s really important for me!
Thank you very much!

Hello Emilio!

I think it is not possible to generate points on a water surfaces. And if you think about it, this makes sense. Water surfaces are so homogeneous that it is not possible to find characteristic points, much more to match them. I guess a big percentage of the images should be covered by land, that has characteristic points.
If all images are calibrated then the orthomosaic will not have wholes. Still, the point cloud will not have points on the water.

Sorry, but I think that photogrammetry may be not the solution for you to map the surface of a lake. But you can map the borders of the lake!

Thank you Luciano for your response. Obviously I don’t want just to map the surface of a lake, but some lakes have been formed next to quarries (for example) and clients wants that the surface of the lake appears in the videos generated from the point cloud or in the 3D model.
So I have generated the borders of the lake but I would need all the surface.

Hi Emilio!
I think that if all images are calibrated the mesh should be generated for all the area, even the lake. I guess there should be less triangles in the lake as there are not points, but the color should be taken from the original images. The mesh is a continuous output, anyway. But, the point cloud should be empty over the lake.
Anyway, if you want the lake surface to appear in the video, you can use the mesh.

A question for PIX4D support. Is there any plans for the soft to “guess” where there is water and treat it accordingly? When it comes to the mesh, it becomes a big pain to clean up wild 3D mesh flactuations around docks, boats and shores. I erase all the mess and then substitute it with a “hand made” flat surface (in SketchUp). If the Pix4dsoftware could guess atleast flat bodies of water and force them to be flat, that will be a dramatic improvement!

Hi all,

As Luciano correctly mentioned, photogrametric software can not deal with water. Water is homogeneous and it´s hard to find common points on the images. In addition to this, water moves. Photogrammetry can not deal with moving points/objects.

As alreday mentioned, the best solution is to use the orthomosaic and/or the 3D Textured Mesh as they will have no holes.

@Dennis: You can erase the noise of the point cloud using our editing tools: https://support.pix4d.com/hc/en-us/articles/202560499

The deleted points will not be taken into account for the Mesh generation.

I have added your idea about the surface to our Suggestion list. Our Product Development Team will consider it for future version of the software.

Best regards,

What if…I don’t want the surface of the lake, but I need the boundary of the lake or the river.

Could Pix4Dmapper auto-fetch the boundary of the river, and export these polylines?

I am afraid this would not be possible. If the water surface was reconstructed then the best workaround would be to use a GIS tool to extract the polyline.

Cheers,

Ina