Spherical Projection

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Christian
Posts: 3
Joined: Tue May 26, 2015 7:18 am

Spherical Projection

Post by Christian »

Hi everyone,

For a university science project we research for workflows to get scanned data into 3d Models and from there get the panorama images onto that Models.

i´m looking for a solution to project spherical equirectangular panorama images to my 3d model that i created from the Pointcloud in Cloud Compare. I came up with this video: http://www.fxguide.com/fxguidetv/fxguid ... i-and-hdr/

Like the workflow described in the video i´ll be interested if there is a way to get this task done in cloud compare. I used cloud compare 90% of my work, its only this small task i missed in the software.

I´ve scanned with the Faro Focus 3D scanner and the same panorama images can be exported out of the delivered software, so my question is to find a workflow to get this task done into cloud compare.

I think it would be very interesting if there is a way to implement this technique (the Link above) into Cloud Compare. Usually I came up with .exr Format and used the Scanner Positions from Cloud Compare. That would be intresting if someone else has the same problem.

Would this be possible in Cloud Compare?
daniel
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Re: Spherical Projection

Post by daniel »

Hi,

In fact the general process of projecting a (standard) picture on a point cloud is already in the TODO list. However this is clearly not in the 'top' of the list (until someone accepts to take this task in charge ;). I'm not sure how much complicated projecting a fish-eye picture would be?

Note that it would be much easier if the picture is already 'calibrated' (i.e. coming from an E57 file for instance with the right sensor pose). What kind of data do you have?
Daniel, CloudCompare admin
Christian
Posts: 3
Joined: Tue May 26, 2015 7:18 am

Re: Spherical Projection

Post by Christian »

Hi daniel,

thanks for your answer, it´s good to here that this task is on the ToDo list. I came up with a tool called JRC Reconstructor, they´ve used this method.

http://www.gexcel.it/en/lidar-software- ... uctor-full

The Faro Focus 3D takes a coloured picture in this equirectengular format and you can save it out from the software Faro Scene. The pictures from the scanner are not that good, so we´ve taken pictures with a DSLR camera, to reproduce this technique. In the end we have a workflow to produce the same equirectangular images (360 degrees) in very high quality. Anyway, it would be nice to use this images instead of the scanner ones. With this technique you can texture a 360 degree 3D (interior) Model from every Scanner Position.

I think the same technology is used to colourise the pointclouds, so there might be a way to take this method to project it onto a mesh.

Another video with detailed Technique can be found here:

http://media.fxguide.com/fxguidetv/fxguidetv-ep178.mp4

The .exr Format is used to get all the exposure values and used to blend from the different projections. So you have the full controll over the brightness/darkness of the image. I think .tif or .jpeg is also an option.

I hope i explained it a bit further.

Christian
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