mikepianka
commented
2 years ago This is an interesting idea I have also thought about. Have you found a complete example that starts with a point cloud and arbitrary point of view XYZ, and then derives an equirectangular 360x180 image from it? Your two links cover parts of the problem but it might be helpful to see a working implementation and then be able to work backwards from there to adapt it to what's available in potree.
My other thought is that this sounds pretty processor intensive, so I wonder what the performance would be like doing it all in the browser? I'm sure it could be possible with some web workers though. Is your idea to give the user the ability to essentially take a 360 screenshot of any area they want? If you had some predefined positions you could possibly preprocess those and then add them to your potree viewer to save some work in the browser.
Definitely interested to hear what you find!
akharroubi
maramusag
Has anyone been able to dynamically generate a 360 panorama image from the potree point cloud, for a given XYZ position, where our points also have color information.?
I am thinking there are a few possible ways
1: We have lovely equations with Spherical Projection, that would be fast and much preferred. As in the PCL C++ library(no thanks) such as https://towardsdatascience.com/spherical-projection-for-point-clouds-56a2fc258e6c or in Python with Open3D , such as https://blog.ekbana.com/planar-and-spherical-projections-of-a-point-cloud-d796db76563e
But these have the problem of the point cloud format they need as input. I could use the original las file, and convert to the formats such as PCL / PCD, possible, but in potree memory on client would be better
2: from every point on the outer bounding box (or bounding sphere) of the point cloud , do a ray trace to your XYZ point, if you intersect any point on the way then use it, overwriting any previous point on your ray you have intersected. As for resolution of the image, we would average points within a range
3: very similar to above, have a Sphere volume, which potree has. We can clip a sphere volume, (potree hightlights everything inside). What we want is every point on the surface of this sphere, and start from the full point cloud bounding sphere, and contract the sphere until we are zero size sphere at out XYZ. Again ignoring any points that intersect and allow average for resolution Is there a way to get every point on the surface of the Sphere volume?