# 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.

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 ...
3k views

### Momentum and order of update problems in my physics engine

This question is a "follow-up" question from my previous one, regarding collision detection and resolution, which you can find here. If you don't want to read the previous question, here's a brief ...
886 views

### Collision detection problems using AABB's

I implemented a simple collision detection routine using AABB's between my main game sprite and various platforms (Please see code below). It works great, but I'm now introducing gravity to make my ...
1k views

### AABB of rotated sprite?

Say I have a sprite. Its AABB is easy to find since I know the width and height. Say I rotate it 45 degrees, I don't think the AABB would be big enough to cover it, so I need a new AABB. How can I ...
1k views

### Calculate an AABB for bone animated model

I have a model that has its initial bounding box calculated by finding the maximum and minimum on the x, y and z axes. Producing a correct result like so: The vertices are then stored in a VBO and ...
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 ...
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 ...
1k views

### AABB Sweeping, algorithm to solve “stacking box” problem

I'm currently working on a simple AABB collision system and after some fiddling the sweeping of a single box vs. another and the calculation of the response velocity needed to push them apart works ...
322 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

### AABB-AABB sliding collision response

I have many objects with AABBs and a player surrounded in an AABB. If I represent my player with a point everything works smooth with detection and wall sliding as a response (for example what wall ...
648 views

### Sensor based vs. AABB based collision

I'm trying to write a simple collision system, which will probably be primarily used for 2D platformers, and I've been planning out an AABB system for a few weeks now, which will work seamlessly with ...
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. ...
1k views

### Trouble with AABB collision response and physics

I have been racking my brain trying to figure out a problem I am having with physics and basic AABB collision response. I am fairly close as the physics are mostly right. Gravity feels good and ...
12k views

### Bounding box of a rotated rectangle (2d)

I can see this has been asked before in various ways. I am struggling to work it out though hence asking again. 2d sprite that moves and rotates. I'm looking to contain it in a bounding box as it ...
135 views

### 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 ...
1k views

### What has the most efficient intersection test against an AABB tree - OBB, Cylinder or Capsule?

I'm currently trying to find collisions in 3D between a tighter volume than an AABB and a tree of AABB volumes. I just need to know whether they are intersecting, no closest distance or collision ...
915 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

### Movement and Collision with AABB

I'm having a little difficulty figuring out the following scenarios. In scenario A, the moving entity has fallen to (and slightly into the floor). The current position represents the projected ...
575 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.
691 views

### How should I do AABB::contains?

Should an AABB "contain" a point when the point is: Exclusive: Only exactly inside the aabb Inclusive: Inside the aabb or exactly on the sides Almost: Inside the aabb or a little bit outside of 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 ...
313 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 ...
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). ...
647 views

### 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 ...
187 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 ...
143 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 ...
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 ...
173 views

### 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 ...
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 ...
463 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 ...
3k views

### collision resolve sphere-aabb and aabb-aabb [closed]

I am currently working on a basic physics engine which does not consider rotations. At the moment I work on collision resolving between aabbs and spheres. Unfortunately I have no idea what a collision ...
263 views

### 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 ...
2k views

### Invalid AABB aabb

Invalid AABB aabb UnityEditorInternal.InternalEditorUtility:CalculateSelectionBounds(Boolean, Boolean) I've got this error ...
97 views

### 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 ...
966 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 ...
1k views

### Find the Contact Normal of Rectangle Collision

It seems a lot of people have asked similar questions on this site, and every time it seems like a whole bunch of answers that don't work are given. Basically, I have two rectangles (AABBs) that ...
1k views

### AABB for a tile based world

I'm on my way with a tiled based game. I have correctly implemented scrolling, position handling etc. I have (before) had a simple collision system that is a really bad one, and now I'm going to ...
29 views

### 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 ...
129 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....
69 views

### 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-...
73 views

### 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 ...
63 views

### 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 ...
652 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 ...
173 views

### Apparent tunneling with issue bounding box collision detection

I'm working on a Break Out game remake and I'm getting a weird bounding box collision detection behavior. It seems like the ball is going under the paddle even if the hit is on top. Weird enough the ...
38 views

### 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 ...
35 views

### 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 ...
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 ...
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 ...