# Tagged Questions

Axis-Aligned Bounding Box (see Bounding Box) - an extremely simplified representation of the size and position of a 2D or 3D graphical object, in the shape of a box.

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### Technique to find a mesh intersecting with a primitive solid without using colliders?

For what it's worth I'm using Unity3d, but I believe the problem is more general. There are hundreds if not thousands of meshes with hundreds of vertices each. There is one sphere that can be ...
140 views

### Could triangles be used for swept-AABB checks between positions?

I'm trying to understand swept-AABB collision detection. When checking for collisions between two positions of an object, I commonly see one of 3 strategies used: Rays: trace rays from parts of the ...
27 views

### Vector and aabb collision [duplicate]

Im having trouble with bullet collisions for a 3d game. I've seen many solutions but they either don't work for my case or are way to complicated. Can someone explain in a pretty simple way how to ...
128 views

### Frustum culling takes ages c++

I have two ways of doing frustum culling taken from different web sources. First one takes 200ms to check 10k AABBs, second around 50ms for the same box count. I read some forum answers, people say 0....
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### Resolving 2D AABB collision problem

I'm adapting the collision resolution code from learnopengl.com for my own engine and since this my first time doing this, I have a problem with how the player position is being modified by the ...
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### When to calculate AABB collisions

I was wondering if collisions are usually calculated the exact moment an object is moved or if it is calculated in the game loop. I haven't been able to find anything on this. Thanks
2k views

### Invalid AABB aabb

Invalid AABB aabb UnityEditorInternal.InternalEditorUtility:CalculateSelectionBounds(Boolean, Boolean) I've got this error ...
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### AABBs in lwjgl 2.9.3

I think I have succeeded in making an aabb out of 6 quads in opengGL but how would i get it to stay with its centre-point at the centre-point of all objects. I know it is easy for one object how would ...
3k views

### Collision between AABB and Circle

I'm programming collision systems for a 2D game engine. The idea is that different systems can interact with each other. So one of the cases would be check collisions between axis aligned bounding box ...
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### Is it possible to not include or erase AABB data from a procedurally generated mesh with Renderer?

I am procedurally generating many thousands of very simple meshes with very simple texture (the same for all meshes and instances) in Unity (5.3.4) with C#. Currently they take more than 100MB in ...
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### Swept AABB vs AABB Calculation Error

I'm having issues running simple AABB vs AABB collision detection. I'm able to successfully detect collisions without checking with velocity. But for some reason my code keeps prematurely firing ...
2k views

### Scale a game object to Bounds

I'm trying to scale a lot of dynamically created game objects in Unity3D to the bounds of a sphere collider, based on the size of their current mesh. Each object has a different scale and mesh size. ...
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### Swept AABB Collision and Response Problems

I am working on a simple 2D game, and I am having problems with collision detection and response. I am using code adapted from this article: http://www.gamedev.net/page/resources/_/technical/game-...
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### How do I deal with AABB sweep ghost collisions?

I've been trying to wrap my head around this for some time now. I wrote an implementation of AABB sweep collision detection. I though I understood the idea but it didn't work as expected. I rewrote ...
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### Resolving collisions with float precision errors

I'm facing a problem when I try to resolve the collision between two units using floats as positions of the units in my game. I am detecting the collisions using the SweptAABB algorithm and if there ...
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### How to make your own 2D AABB collision system in unity?

I can't use the built in unity 2d physics engine for my game, so I tried to make my own using the unity bounds.Intersects, that is working perfectly but my problem is that I don't know how to make the ...
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### Partial mesh culling by checking against the AABB-tree of objects vertices instead of only the AABB of the whole objects

First thing: this is more of a conceptual question than an implementation oriented one, but still tips about implementation will be very much welcome if you happen to have any (athough I have some ...
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### 2D AABB vs AABB side of collision and collision depth

I realize there have been a multitude of questions involving 2D AABB vs AABB collision, but the questions and responses always avoid the simple questions that make it difficult. To keep things ...
390 views

### Get intersected volume of two planes in 3D

I'm working on AABB - AABB collision response and I'm having trouble figuring one part out. My situation is as follows (see image). I have a player AABB (blue) and an object which collides (brown). ...
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### objects bouncing off of each other as collision response

At the moment, how I solve collision between 2 objects looks like this: (all the data of the objects is stored in float arrays, since its OpenCL) float impulseX = mass[id] * vel[id3 + 0]; float ...
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### AABB in OpenCL not working correctly

I have this really simple OpenCL kernel. The values get in correctly and get out correctly. So the error must be somewhere in the kernel. All the parameters are float arrays. pos rot vel and aPos aRot ...
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### Best collision algorithm for Axis Aligned Bouding Boxes [duplicate]

I have a number of quads (suppose like 20-40) and i want to quickly check the collisions between any of them. I would like to know if there's a quick algorithm to do that 60 times per second without ...
573 views

### AABB of a sphere's screen space projection

What is a nice, neat way to get the AABB of a sphere's projection onto the screen? This is to determine simplified geometry for lights in deferred shading.
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### Bullet btGImpactCollisionAlgorithm

I have a question about Bullet and in particular GImpact. When, the collisiontestpair(a, b) is called where GImpact pair check algo will be called on the btGImpactMeshShape, does it do a AABB tree ...
186 views

### Creating a Collision Detection system [duplicate]

I'm currently working on 3D project (C++) and I have now come to writing the collision detection systems. Basically my question is regarding how to architect it. All the collisions are either ...
63 views

### Positioning of AABB / Rectangles

I am wondering what is the best way to position rectangles, the ways I have thought of are: Have an x and y at upper left, then have a width and height Have an x and y at upper left, and an x and y ...
462 views

### How do I resolve a collision of a circle with two rectangle corners?

I'm writing a simple non-physical one-circle-to-many-rectangles collision detector/resolver. For collision detection, I'm using a very common algorithm, and it's working pretty well. For collision ...
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### How to resolse collision between moving and static AABB?

What I have is a map represented as list of Rectangles and player's rectangle. Also I have function to determine depth of the collision: Point TestAABBAABB(Rectangle a, Rectangle b) { ...
312 views

### How to resolve collision between a dynamic AABB and static AABB?

I wanted to ask, how do I resolve collision between 2 cubes - in my case I want to push a moving / dynamic cube (used for the player) out of another static cube (used for the floor or objects in the ...
507 views

### How do I avoid causing more collisions, when resolving multiple AABB collisions?

I have a lot of AABB bouncing on the screen. Doing collision/response between 2 AABB is fairly easy, but how do you handle this when you can be pulling AABB's apart but making them getting into ...
914 views

### How do I avoid 3D AABB collision response getting stuck at block edges?

I want the player to be able to slide along cubes, but without getting caught at the seam between 2 adjacent cubes. I've gotten it so that I can do x collision, with sliding, and y, and z, but I can'...
2k views

### How do I make a collision between AABBs slide?

I have a room with objects inside. Each object has it's own AABB. I know how to check for collisions between the objects with an AABB-AABB intersection. How do I calculate an appropriate collision ...
3k views

### Hexagon collision detection for fast moving objects?

A object has a position and a speed vector. Usually only the position is used to check if two objects collide, this is problematic for very fast moving objects as it can happen that the object moves ...
650 views

### AABB swept collision response with voxel world

I followed this tutorial: link and I was able to make it work with 3d voxel world collisions. But the problem I have is with collision response. I want to make player slide against the wall if he is ...
138 views

### Why Is My AABB Collision Detection Not Working

I am going to be making a 3D game and I need to be able to test for accurate collision. I was able to get bounding sphere collision working (too inaccurate to be used for the whole game), but AABB ...
312 views

### Slopes vs. Rectangles: Different Collision Points

My platformer has both rectangular tiles and right-triangle slopes with rectangular hitboxes. My sprites are also rectangular. Collision with only rectangular tiles works well. Even if there are ...
114 views

### Can't get the logic behind my AABB collision

This is my collision detection function in the maze game im working at. I never made a game before and I dont have that much programming experience. The question I keep asking me continously is why ...
320 views

### How do you prevent AABBs from passing through each other?

I know what an AABB is, but I don't know how you would check for collision with an object that is going really fast. If an object goes fast enough, it can skip over other bounding boxes without it ...
2k views

### 2D AABBs and resolving multiple collisions

Okay, so this is a problem I've been trying to figure out for quite some time. Mine is a 2D platformer game with a world made up of (usually) immobile tiles and mobile sprites, both of which use AABBs ...
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### Thick Ray interaction with AABB

I would like to intersect a thick ray (actually a cylinder) with an AABB. The current code to perform intersection with the ray is the following. template <class RealT> bool CAABB<RealT>:...
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### Degenerate AABB (axis aligned bounding box), does this always intersect?

I'm studying ray-AABB intersections and I'm asking myself: what would happen if one of the dimensions of the axis aligned bounding box was degenerated? For instance: AABB_min = {1,1,1} AABB_max = {...
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### AABB vs Rectangle

I'm trying to wrap my head around 2D physics and stumbled upon Axis Aligned Bounding Boxes, and I have a couple of questions regarding them. In all AABB structs I could find out there, people prefer ...
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### AABB SAT code detects collision wrongly [closed]

I've been having trouble getting my SAT code working using AABBs, and I've been trying to find a solution but, I'm scratching my head. For some reason, it detects collisions very wrongly, as shown by ...
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### AABB collision detection not detecting in some cases

I'm using simple AABBs in a tile based world, and for some reason the algorithm does not detect collisions when moving towards the left and then down. I actually upload a video to YouTube to ...
186 views

### How to calculate new velocities between resting objects (AABB) after accelerations?

lately I have been trying to create a 2D platformer engine in C++ with Direct2D. The problem I am currently having is getting objects that are resting against each other to interact correctly after ...
245 views

### Incorrect frustum culling with center/half-size AABB

I'm trying to implement an axis-aligned bounding box with center/half-size instead of min/max. And I have some problems when it comes to create a method to detect if the aabb is visible or not. I try ...
964 views

### AABB vs OBB Collision Resolution jitter on corners

I've implemented a collision library for a character who is an AABB and am resolving collisions between AABB vs AABB and AABB vs OBB. I wanted slopes for certain sections, so I've toyed around with ...
225 views

### Overlapping sibling problem in AABB tree

I'm trying to make a real-time GPU (CUDA) ray tracer, and for now I'm tracing single rays, but I've ran into a problem: the BVH. This [PDF]paper has been my inspiration for the theoretical part, and ...