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Questions tagged [octree]

An octree is a tree data structure in which each node has eight child nodes. A major application of octrees is in 3d graphics as they are the primary structure used for storing voxel (volumetric pixel) data.

Wikipedia: "An octree is a tree data structure in which each internal node has exactly eight children. Octrees are most often used to partition a three dimensional space by recursively subdividing it into eight octants. Octrees are the three-dimensional analog of quadtrees."

Relevant topics include voxels and color quantization.
For more information see http://en.wikipedia.org/wiki/Octree

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Separate objects in a point cloud

I am looking to Separate a point cloud into unconnected objects, I have tried using k-means algorithm, but it didn't do the whole job. I'm looking to improve the results shown in the picture i added. any thoughts or directions? My cloud, separated…
Asaf Tzur
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Repacking voxel data for efficient storage

I've got 3D voxel data, and I want to re-package it for memory efficiency and fast access. The data is generated in a regular octree, one integer value per cell. Unfortunately the data is not sparse, but the cells with the same value should be…
user1387
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Arguments length error when trying to test model using party package in R

I have divided my data set into two groups: transactions.Train (80% of the data) transactions.test (20% of the data) Then I built the decision tree using ctree method from party package as follow: transactions.Tree <- ctree(dt_formula,…
Shaher Jamal Eddin
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Octree - what cells does moving object affect?

I want to use an octree as an OGL scene representation and I have some moving object in there. I would also like to use this octree to accelerate the collision detection. Is there any good algorithm that gives you the path in octree (all cells/nodes…
Hitokage
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Multi-scale huge 3D volume rendering using WebGL

I'm rendering a huge 3D volume using WebGL and the ray casting algorithm is implemented in the shader(glsl). The volume is created from bio-image stacks. What I want to do is to keep zooming in and out smoothly when rendering this 3D volume. But the…
hby001
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Node depth from octree location code

In the Article Advanced Octrees 2: node representations it is stated: The AABB of the node can be stored explicitly as before, or it can be computed from the node’s tree depth stored implicitly inside the locational code. To derive the tree depth…
gnzlbg
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What is the name for a quadtree/octree like tree with an arbitrary number of child nodes?

So if a node has 2*2 subnodes it is called a quadtree (2*2=4). If a node has 2*2*2 subnodes it is called an octree (2*2*2=8). Therefore if you work in 2D it is often good to use a quadtree and in 3D it is good practise to use an octree. But are…
kke
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Morton code to store 3D float postitions

I'm trying to implement what's explained in this article: http://devblogs.nvidia.com/parallelforall/thinking-parallel-part-iii-tree-construction-gpu/ // Expands a 10-bit integer into 30 bits // by inserting 2 zeros after each bit. unsigned int…
misterD
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Lazy load an Octree from a file

I work on a 3D map renderer for iOS and Android using which is mainly written in C++. I use an Octree to load and store data from a file. So far all is fine, rendering small to medium maps of some square km is all cool and all works fluid. But now…
benjist
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Recursively build a list based on length and another list

I'm trying to make my own version of an octree, and have hit a problem if you try add points of different sizes, as going down a depth level will just overwrite everything, therefore removing any information on larger blocks. I thought the best way…
Peter
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Collision detection using fcl and ros wiki for octree and regular object

I have two objects. The first object is my robot which I want to represent it as a shpere and the second object is the obstacle that has unkonwn shape. I want to represent the shape of the obstacle with an octree. How can I use the api of the fcl to…
RSA
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Collision detection using FCL following the API of ROS wiki using shere and octree objects

I want to use FCL library for collision detection only. My first object is the robot where I want to specify it using a sphere shape and second the obstacles in the world using octree. I tried to follow the instruction in order to create this…
RSA
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Simple octree traversal: How to get the intersection points with AABB

This is my first question here on stackoverflow, so i hope i got all things right. For an java project i need to use an octree for raytracing. I already created an simple octree (without neighbour information or something) and sorted the triangles…
user3833989
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Most used colors in an Image in Java Programming

I'm finding difficult to get the colors used of an Bitmap image in Java. How to get the most used colors of an image in java programming with octree color quantization algorithm or any other better algorithm?
Vishanth
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Only upper right part of image rendered when using octree

I'm currently implementing the paper of Revelles, Urena and Lastra "An Efficient Parametric Algorithm for Octree Traversal". In Ray - Octree intersection algorithms someone implemented it and pasted his code. My implementation should be the same,…
alefhar
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