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Bounding box dimensions and octree calculation

Posted: Tue Jan 16, 2024 10:05 am
by Michael123
Hello,

I have a question regarding the calculation of bounding box dimensions and the resulting octree levels.

- In my understanding, the bounding box dimensions represent the maximum values of either the x, y, or z coordinate distance of a point cloud. Is that correct?

-As mentioned on the CC Wiki, octree cells are formed by dividing cubes into 8 equivalent sub-cubes from an initial box. By default, octree subdivision is initiated from the square bounding box of a cloud. Does that mean that, by default, the octree distance can be manually calculated as the maximum dimensions of a cloud (x, y, or z) divided by 2 to the power of the octree level? For example, if the distance between the xmin and xmax values equals 10 m and is the biggest dimension of a certain PC, does that mean that the octree distance of octree level 1 equals 10/(2^1)=5 m?

I didn't find any explanation on that. I did some testing by manually calculating the octree distance and came pretty close to the calculation results of CC, but it was not the exact same value.

Best regards,
Michael

Re: Bounding box dimensions and octree calculation

Posted: Tue Jan 16, 2024 5:19 pm
by HeadLess
I think you answered all of your question.

bounding box correct

number of box = 2^octreeLevel, and each box has the same size. so if you know the bbbeforehand you can calculate the resulting octree box size.