Timeline for Finding nd - m dimensional neighbors for a given node within a balanced hyperoctree
Current License: CC BY-SA 3.0
10 events
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| May 23, 2017 at 12:37 | history | edited | CommunityBot |
replaced http://stackoverflow.com/ with https://stackoverflow.com/
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| Apr 14, 2014 at 14:54 | comment | added | gnzlbg | let us continue this discussion in chat | |
| Apr 14, 2014 at 14:40 | comment | added | Yuval Filmus | @gnzlbg Regarding your "stencil", this looks like some kind of optimization, although you don't explain what you do in the "i" cases in which you need to go (at least) one level up. To start with, you can come up with some algorithm not having this kind of optimization, and later you can optimize by generalizing the current approach; a prerequisite, however, is that you understand how it works, which I suspect you don't. | |
| Apr 14, 2014 at 14:38 | comment | added | Yuval Filmus | @gnzlbg Regarding 1, if your octrees are sparse then when you go down you might discover that you have no node with a give index, that's all. Each node in an octree always has an index, just like the link describes. The only difference in the sparse case is that not all nodes at a given depth are actually there. | |
| Apr 14, 2014 at 14:31 | comment | added | gnzlbg | thanks for your feedback, I've tried to improve the question. Could you let me know if it is better now? | |
| Apr 14, 2014 at 13:49 | comment | added | Yuval Filmus | @gnzlbg You will have to provide more information on what exactly you're doing: what exactly is your data structure, and what works for low dimensions. This is impossible to glean from your question, unfortunately. | |
| Apr 14, 2014 at 11:25 | comment | added | gnzlbg | Regarding 1 (after reading the link): I use the octree to represent a topology (without any spatial information). So I have the parent/child edges for every node, but I don't have e.g. coordinates. I'm specifically looking for a way to find the set of neighbors of codimension m from the tree structure only (i.e. the bare minimum). | |
| Apr 14, 2014 at 11:14 | comment | added | gnzlbg | Regarding 2) Thanks for the link, I'm looking into it! (Please someone upvote him, I can't since my reputation is < 15...). | |
| Apr 14, 2014 at 11:13 | comment | added | gnzlbg | Regarding 1) I can only find a neighbor by adding $d_x$ to $x$ if I'm using some sort of hashing (spatial-/geohashing) to store my nodes right? I am not using it since that would require me to allocate memory for all possible nodes up-to a given level and in my case the octrees are very deep but very sparse, or did I understand this wrong? Is there a general way of find the neighbors by using tree traversals only? | |
| Apr 14, 2014 at 2:00 | history | answered | Yuval Filmus | CC BY-SA 3.0 |