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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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Range search within specified radius in an Octree

I am interested in particle algorithms like the N-Body, and SPH. One of the important steps in these applications is, given a query point, to find the particles lying within a specified sphere of radius 'h'. Now I have heard that Octrees are good…
smilingbuddha
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CPU Ray Casting

I'm attempting ray casting an octree on the CPU (I know the GPU is better, but I'm unable to get that working at this time, I believe my octree texture is created incorrectly). I understand what needs to be done, and so far I cast a ray for each…
Benzino
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How to fill gaps between different level of detail in octree-marching cubes algorithm?

I'm trying to implement marching cubes on octrees. Here is a 2D drawing of what I am trying to figure out, it'll be easier to explain: Each node of the octree represent a square in the plane (or cube in space), and stores a value for the potential…
LucioleMaléfique
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Octree implementation

Possible Duplicate: Fast, templated, C++ Octree implementation Can anyone suggest some well-tuned implementations out there for the octree on the CPU or the GPU in C or C++? Also since Octrees can be represented with and without pointers, can…
smilingbuddha
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Bind Texture in Repeat Mode

I am trying to store an octree in a 3D texture in OpenGL for use on the GPU using Cg, from a chapter in GPU Gems 2 found here http://http.developer.nvidia.com/GPUGems2/gpugems2_chapter37.html. However the results I am getting are incorrect. I think…
Benzino
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Octree: Am I doing it wrong? Getting very slow insertion

I am writing an Octree based container from anywhere between 10 points to 1 billion points into memory.. Because of the amount of data being loaded, I need to be watchful of the memory consumption. Everything seems to be working properly and…
user1000247
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What data structure shall I use to process a polygon mesh in a "subdivisional" way?

Here is the problem: I have a geometric mesh which contains a number of polygons(triangle) to be processed parallelly, thus I need to an efficient method to obtain the polygon data in specific area, ie, given the bounding…
Wesley Ranger
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Traverse octree using Revelles algorithm in a dynamically uniform way GLSL

I am trying to traverse my octree in my compute shader in GLSL (v450) using the revelles algorithm with ray marching in real-time. I have managed to traverse it and I get an image but my fps is extremely low, around 0-5 fps. As the algorithms…
Tothema
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Fast volume representation, modification and polygonisation

I am looking for ideas for algorithms and data structures for representing volumetric objects. I am working on a sculpting system, like sculptrix or mudbox, and want to find a good implementation strategy. I currently have a very nice dynamic…
DaleyPaley
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Test if Cube is inside Sphere - Fastest Method

Is there a faster way to check if an axis aligned cube is inside a sphere than to test separately if the 8 corners are inside the Sphere? I'm walking through an Octree checking if its cube-leafs are intersecting or enclosed within a Sphere. I found…
BoshWash
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What is the difference between marching cube and octree?

Is octree a special case of marching cube ?? I mean does octree use same triangulated cubes of marching cube. I know that octree is a 3d form of quadtree. I just want to know whether I am in correct direction or not. After the tree have been…
solti
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Strategies for packing data into OpenGL 3D array

I am implementing a voxel raycaster in OpenGL 4.3.0. I have got a basic version going where I store a 256x256x256 voxel data set of float values in a 3D texture of the same dimensions. However, I want to make a LOD scheme using an octree. I have the…
Victor Sand
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Are sparse AABB trees made with pointers?

I'm using an octree of axis aligned bounding boxes to segment the space in my scene where I do a physics simulation.The problem is, the scene is very large(space) and I need to detect collision of large objects at large distances as well as small…
ulak blade
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What's the most storage efficient Octree structure for reconstruction?

I've coded a full octree implementation without too much optimization for 3D reconstruction, however, the tree structure contains too many pointers, and cannot support more than 256^3 voxels. Theoretically, for a non-tree structure if I used a…
tomriddle_1234
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implement volume rendering with object order empty space skipping

I learn some volume rendering techniques from the Advanced IlluminationTechniques forGPU-Based Volume Raycasting of scenegraph 2009 course note. I am interested in the object order empty space skipping, which rasterizing the bounding box into lots…
toolchainX
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