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1
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0answers
24 views

How to move octree data correctly from parent to child?

This is my first question, so apologies if it is a repeat, I have had a look at the other questions and I still can't seem to find an answer to this. So I am making a recursive octree in OpenGL. So ...
-1
votes
1answer
107 views

Should I use octree or quadtree for my spacial data structures? [closed]

I would like to know the advantages and disadvantages of using octree or quadtree for spacial data structures? In a 3d gaming setting would you ever need more than 4 children nodes? Does it take ...
0
votes
0answers
81 views

Binary Space Partitioning of 3d Triangle Mesh (for finding nearest points)

I'm writing a Binary Space Partitioning (BSP) tree for the purpose of optimizing finding the nearest point on the surface of a 3d triangle mesh with respect to another point. I'm currently following a ...
0
votes
1answer
67 views

How can I split up a large model into an octree codewise?

For collision detection, I am attempting to split up a large model into an octree. If we take this black thing thing to be the ship (104,000 vertices): Then I would like to split up the faces I ...
0
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0answers
85 views

Actual use of sparse voxel octrees in a game engine

Looking for different ways to speed up my simple voxel system reducing the number of voxels and generated triangles, I stumbled upon these sparse voxel octrees. Now, I read a lot about it: how do they ...
0
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2answers
221 views

Implicit Functions and extracting an isosurface

I recently discovered a paper on Dual Marching Cubes which produces a much reduced poly count to other methods like Dual Contouring and Marching Cubes, however a recurring theme when reading these ...
0
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0answers
23 views

Function for building an isosurface (a sphere cut by planes)

I want to build an octree over a quarter of a sphere (for debugging and testing). The octree generator relies on the AIsosurface interface to compute the density and normal at any given point in ...
2
votes
1answer
502 views

Marching cubes over an octree dual - how?

In Dual Marching Cubes the dual of an octree is tessellated via the standard marching cubes method. But the classical marching cubes algorithm operates only on cubes with eight vertices (it uses signs ...
3
votes
1answer
192 views

Determine wheter an octree node needs to be continue

For collision detection (moving vs. non-moving) in my current project, I decided to implement an octree approach after the preselection. The only collision detection I'm currently using is a ...
3
votes
1answer
360 views

Dynamic Quad/Oct Trees

I've recently discovered the power of Quadtrees and Octrees and their role in culling/LOD applications, however I've been pondering on the implementations for a Dynamic Quad/Oct Tree. Such tree would ...
8
votes
1answer
1k views

How to efficiently render a large terrain mesh?

Recently I've been stuck on a problem thinking about the best way to generate a terrain into my game. In another projects I normally used heightmaps, so all the core-work was based on the engine used, ...
1
vote
1answer
92 views

How to create more vertexes from within a shader in OpenGL?

when rendering voxels in octrees, the only information necessary is the current octree-level, -position and colour/texture. But one has to send eight vertices to the rendering pipeline in order to ...
0
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0answers
106 views

Overlap detection, nearest neighbors

I'm trying to get something similar to the Nearest Neightbor Problem, except I only want neighbors with radius overlapping a radius, and all of them. I'll explain my problem before explaining what I ...
3
votes
2answers
2k views

When would you use an octree in a voxel Engine?

I've been reading about Octrees, and I understand how they work (or at least I think I do). However, I can't figure out why you would use octrees instead of a simple multidimensional array. In my ...
2
votes
0answers
450 views

C++ FPS game collision detection with partitioning system or physics engine? [closed]

I'm working on a small FPS game (as a hobby and for learning purposes, nothing else) built with C++ in OpenGL (from scratch). Documenting online on the kind of strategy someone would approach with ...
1
vote
2answers
2k views

Octrees as data structure

In my cube world, I want to use octrees to represent my chunks of 20x20x20 cubes for frustum and occlusion culling. I understand how octrees work, I just dont know if I'm going about this the right ...
2
votes
1answer
189 views

About Octrees Usage

I'm studying about Octrees since I've read they're used to organize my elements in space, but I couldn't find any practical example so I'm kinda lost as to their use. From what I could understand, ...
2
votes
4answers
816 views

create terrain with some vertical cliffs, natural arcades, caves using octree

I am about to start creating the first terrain. I would like to create a terrain with vertical cliffs, natural arcades and caves. For instance in one point the terrain might look like this. I want ...
0
votes
3answers
1k views

How to draw only visible tiles?

I have a big map with isometric tiles(3d camera), how can i draw only visible tiles ? Whats the best way to do that ? space partitionning (octrees etc...)?
1
vote
1answer
752 views

Octrees and Vertex Buffer Objects

As many others I want to code a game with a voxel based terrain. The data is represented by voxels which are rendered using triangles. I head of two different approaches and want to combine them. ...
6
votes
1answer
1k views

Octree implementation for fustrum culling

I'm learning modern (>=3.1) OpenGL by coding a 3D turn based strategy game, using C++. The maps are composed of 100x90 3D hexagon tiles that range from 50 to 600 tris (20 different types) + any ...
4
votes
3answers
2k views

Scene graphs and spatial partitioning structures: What do you really need?

I've been fiddling with 2D games for awhile and I'm trying to go into 3D game development. I thought I should get my basics right first. From what I read scene graphs hold your game objects/entities ...
1
vote
1answer
446 views

Octree subdivision problem

Im creating octree manually and want function for effectively divide all nodes and their subnodes - For example - I press button and subnodes divided - press again - all subnodes divided again. Must ...
2
votes
1answer
2k views

Would someone please explain Octree Collisions to me?

I've been reading everything I can find on the subject and I feel like the pieces are just about to fall into place, but I just can't quite get it. I'm making a space game, where collisions will ...
2
votes
1answer
345 views

Frustum culling with an octree: one AABB per bone or one AABB per object?

I've constructed an octree for use in frustum culling. The question is, should I insert an AABB for each bone of each object, or just the one AABB for the object?
7
votes
1answer
615 views

Octree division

I have an octree, with a high poly rabbit inside it, and a 12 polygon platform. The deal is this. You're shooting a ray at the rabbit. He of course dodges (or you miss). The yellow beam is your ...
2
votes
2answers
1k views

Sparse Voxel Octrees which parts on GPU or CPU?

I'm currently doing research into building my own voxel engine and found a lot of articles mentioning SVOs as the best mechanism. I just wanted to know that I understood the algorithm correctly, ...
5
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1answer
456 views

Handling polygons in multiple nodes of an Octree

I'm building a 3d software renderer for grins to learn the math and rendering concepts. I've implemented the basic drawing of polygons with some basic optimizations like back face culling and frustum ...
3
votes
2answers
112 views

Rays starting in an octree node

I just fixed a bug where rays starting and ending in an octree node were not detected as octree node hits (because the ray doesn't hit the sides). I'm changing the code to check if a ray starts in ...
4
votes
1answer
745 views

Raycasting problem

I have a problem with my raycasting. I have 8 cubes, that define the first level of an octree (Eg. they create bigger cube). I need to raycast them and "render" each cube. If I have only one cube, ...
2
votes
1answer
280 views

Octree contains tris, shapes, models or both?

Right now, each node of my octree contains a list<Triangle*> (pointers to mesh triangles). So basically an octree query returns poly soup. Sometimes I want to query the octree for entire ...
0
votes
2answers
173 views

Volume that encompasses the whole scene?

I'm thinking that the straight-forward way would be to just iterate through the objects and just find the maximum and minimum coordinates on each axis, but this seems a little bit unoptimal. Is there ...
2
votes
1answer
404 views

How to efficiently organise all object in a large space

I've just about started with a project I've had in mind for ages. I don't quite know how to start such big projects (bigger than Pong, anyway), so I thought I would get started by making a basic ...
4
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1answer
1k views

Are Loose Octrees Too Loose?

I've been reading Real-Time Collision Detection and for loose octrees it recommends expanding each node's AABB length by a factor of 2, making its expanded volume 8 times as large. I am surprised ...
8
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4answers
3k views

What library for octrees or kd-trees? [closed]

Are there any robust performant libraries for indexing objects? Objects would have bounds themselves, rather than being represented by points; and an object could therefore be in more than one ...
7
votes
3answers
2k views

Optimizing Octree Rendering

Say I have an octree and at a certain level I store VBOs in that octree. I know the dimensions of of the nodes that own the vbo so I can do basic frustum culling. That works nicely because everything ...
13
votes
2answers
4k views

What's the state of the art in Space Partitioning for games? [closed]

I know about BSP trees, Octrees and Portal that where used for a long time. But modern games still use this systems or they are using new things? If it's possible with pros and cons, considering ...