Collision detection is the determination of whether or not two or more entities make contact with each other during gameplay.

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how get collision callback of two specific objects using bullet physics?

I have got problem implementing collision callback into my project. I would like to have detection between two specific objects. I have got normall collision but I want one object to stop or change ...
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2D Collision: Check before or check after?

I'm using velocity to move my character, I just add/subtract 0.4f and then update the players position in the update loop. I was wondering, when would be the best place to check for collision? Do I ...
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Collision response for 2D racing game

The title is fairly self-explanatory. I have a 2D racing game that utilizes per-pixel collision detection (the track is essentially two bitmaps, one for the graphics, one for collision data). The ...
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299 views

Lerping character moving up and down slope tiles

So, when interpolating position against a standard 'horizontal' platform, everything works great. What happens is something like this..... (Question continues after graphic) Now, the question I ...
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Platformer Starter Kit - Collision Issues

I'm having trouble with my game that is based off the XNA Platformer starter kit. My game uses smaller tiles (16x16) then the original (32x40) which I'm thinking may be having an effect on collision ...
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735 views

Character jittering with this tile based collision code

I have been trying to get my collision code working for hours now but with every resource I have tried my character still jitters. First I tried using the platformer sample but my character still ...
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Line-Rectangle Collision Detection and Response

I've looked through Google and none of the solutions seem to pinpoint my idea. Ultimately, I want to create a level editor where I can draw lines and have them exported to a file for my engine to ...
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3answers
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Collision detection of convex shapes on voxel terrain

I have some standard convex shapes (cubes, capsules) on a voxel terrain. It is very easy to detect single vertex collisions. However, it becomes computationally expensive when many vertices are ...
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1answer
238 views

Wall-sliding Collision Response Only Works On One Axis (2D)

"sprite" is the player object, velocity is a Vec2 that tracks movement (is set to -1, 1, or 0 at any given time), each sprite in "sprites" is a wall of the same size as the player (everyone is a block ...
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452 views

How to detect if a ball will collide with another, and the normal vector of the collision?

So I have a 2D game involving balls (circles) colliding. I want to be able to detect if two balls will collide before it happens, and the normal vector of the collision if a collision is going to ...
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3answers
887 views

Using uniform grids for collision detection - Efficient way to keep track of what a cell contains

I was looking for an efficient way to implement collision detection in a 2D game. A way that won't result in an O(n^2) level of complexity. A lot of people recommend to use Uniform Grids for this ...
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260 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 ...
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When is a quadtree preferable over spatial hashing?

I'm making a 2d platformer with lots of objects at the same time. They're all AABB collision detected. I first tried a quadtree to decrease the number of of objects to check, tried a few different ...
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532 views

Collision Detection - Slide Around Sprite

I'm creating an RPG using XNA/C# and am trying to add some complicated collision detection code. I have the playable character 'Wizard' and when it collides with something, a method gets called in his ...
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2answers
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How do I detect multiple sprite collisions when there are >10 sprites?

I making a small program to animate the astar algorithm. If you look at the image, there are lots of yellow cars moving around. Those can collide at any moment, could be just one or all of them could ...
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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 ...
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1answer
733 views

Collision detection in libgdx

I am currently writing a little zelda like game and have a little bit of a problem with collision detection. It works but the the character stands to far away from the object. Here is my player ...
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2answers
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How to check for cube collisions?

I want a method, which takes two "ObjectBox" objects (A "ObjectBox" has .getX() .getY() .getZ() .getSizeX() .getSizeY() .getSizeZ() methods) as a parameter and return true if the two Boxes are ...
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2answers
338 views

Tools to generate convex collision geometry

Does anyone know tools to generate convex collision geometry from given 3D model? For example, UDK's Static Mesh Editor can do this; Valve instead recommends to use smoothing in 3D editor. Desired ...
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1answer
751 views

How does the SAT collision detection algorithm work

There are a lot of tutorials and sample code available showing how to implement the SAT collision detection algorithm. But can someone explain, without math or code, what are the general principls ...
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3answers
761 views

Collision Detection Problems

So I'm making a 2D tile based game but I can't quite get the collisions working properly. I've taken the code from the Platformer Sample and implemented it into my game as seen below. One problem I'm ...
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1answer
636 views

3D RTS pathfinding

I understand the A* algorithm, but I have some trouble doing it in 3D to suit the needs of my RTS Basically, in the game I'm making, there will be agents with different sizes of OBB collision boxes. ...
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1answer
164 views

Voxel terrain collision detection with AABBs

I'm working on implementing collision detection on voxel terrain (Like Minecraft) with AABBS. Right now, I have it so I can tell if a point is within a voxel or not, I do this by having a 2D byte ...
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AABB collision resolution issues

I'm trying to make a character collide with some tiled terrain. I have an issue with the collision resolution, and after days of shooting in the dark ant not finding any relevant help online, I'm no ...
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Storing rigid body collision shapes in local or world coordinates

I'm writing the beginnings of a lightweight 2d rigid body engine (in javascript, as a hobby project), and i'm debating whether to store collision shapes in local or in (updated as needed) world ...
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1answer
859 views

Box2D: Efficient method to create b2Chainshapes for a tile-based map?

I'm working on a platforming game with tile based levels. I store the collision model for my tileset in an array. This is how the collision model for a 4x4 tilesheet would look like (I can't post ...
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166 views

How can I make it so that my player object doesn't penetrate world collision when I'm holding down movement keys in that direction?

Right now I have a player object and an obstacle, both with bounding box rectangles around them. The issue is that when my player runs into this obstacle, as long as I'm holding down the movement key, ...
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968 views

How to detect screen boundary using AndEngine GLES1?

I am using the AnalogOnScreenControl to move my sprite around the screen. I would like to restrict the sprite so it can not move outside the screen boundaries. I have tried putting a line at the ...
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1answer
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Java 2D Tile Collision

I have been working on a way to do collision detection forever, and just can't figure it out. Here's my simple 2D array: for (int x = 0; x < 16; x++) { for (int y = 0; y < 16; y++) { ...
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452 views

How can we match polygon data structure with a background image

I am referring to this fireball game. The ball will collide with background, which is in polygon form. I was wondering, how I can match my polygon data structure with the background image. Say, I ...
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How to detect which edges of a rectange touch when they collide in iOS

I'm creating a basic "game" in iOS 4.1. The premise is simple, there is a green rectangle ("disk") that moves/bounces around the screen, and red rectangle ("bump") that is stationary. The user can ...
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1answer
441 views

JBullet - Detecting when 2 objects collide?

How can I detect when 2 collision objects collide with JBullet? Currently, all body types are going to be of type RigidBody. I have quite literally been trying to find the answer of this for over 2 ...
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Platformer raycast collision detection

I'm using Unity to create a 2D platformer. For collision detection, I'm using raycasting to detect any possible collisions with specific collision layers, and adjusting the desired delta x & y ...
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implementing collision detection and handling for tiled 2D world with smooth wall sliding

Im using SFML 2.1 for graphics and my game structure follows SFML book quite closely (SceneGraph implementation etc) My world consists mostly of characters (around 1-400, moving around) and tiles ...
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1answer
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How can I determine which direction a 2D collision is occurring from?

The problem is as follows: Think 2D Zelda (Links Awakening, A Link to the Past) style movement where you can run into walls from any of the four cardinal directions, or basically up, down, left, and ...
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How do I calculate collision response between a sphere and a plane?

I'm trying to create a simple 3D game and need to constrain the player within the limits of the game world. When the player hits the sides of the world I want the player's ship to bounce off slightly. ...
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Polygon editor to draw collision data over image

I need an editor to plot a polygon over the texture for of a ship in my game. It would look like this.. Where the red is the collision outline and the image is the texture. I want to store the ...
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Collision Filtering in Box2D

I have four bodies in my Box2D World. Each are polygon shape, with some physics parameters. Now when the game start, I need one of the bodies from the World (BodyA) to not be allowed to collide with ...
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Collision with tile corners/seams in 2D platformer

There seems to be a lot of somewhat related questions answered already, but none I read answered my exact problem. I have a 2D platformer whose world is made entirely out of tiles that are in a ...
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Effects of collisons: broken glass, damaged cars, how are they created?

My question is related in particular to achieving the effects of collision in game engine, how is this done? I have searched a bit, read from the internet and went through a few tutorials, and saw ...
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I need help with 2D collision response (of stacking rotating polygons, with friction and gravity, for a game)

Hi I am looking for suggestions on how to write a collision response for game programming purpose (so not a scientific simulation). I am dealing with 2D polygons that are rotating, and I want them to ...
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Closest point on an ellipsoid

I need to know how to get the closest point on the surface of an ellipsoid to another point. I had an idea, but apparently i was wrong, and oversimplfying. What i did was squash the ellipsoid and ...
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Why do we use physics engines for collision testing or raycasting?

There is a thing I don't understand about game engines: why it is so common to use physics engines to do raycasting or collision testing? Say that you have a 3D scene loaded in your scene manager ...
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Create bullet physics rigid body along the vertices of a blender model

I am working on my first 3D game, for iphone, and I am using Blender to create models, Cocos3D game engine and Bullet for physics simulation. I am trying to learn the use of physics engine. What I ...
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Circle-Rectangle collision resolution

I have a non axis aligned rectangle, like a car, in my game. I have to check and resolve the collision between the rectangle and circle, which is stationary. I have found lots of ways to determine ...
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2answers
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Collision Detection problems in Voxel Engine (XNA)

I am creating a minecraft like terrain engine in XNA and have had some collision problems for quite some time. I have checked and changed my code based on other peoples collision code and I still have ...
2
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1answer
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Attach to a GameObject after collision? [duplicate]

How can I make a GameObject attach (or "stick") to another GameObject after collision? The problem: I want the GameObject to attach after collision even if it changes scale. What I have tried: ...
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Collision detection between axis-aligned bounding box and bitmap (pixel perfect) terrain

Working on a Worms-type game, I have my objects in bounding boxes and they sit on the pixel terrain. Currently I am able to successfully do the collision detection for objects when they enter the ...
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How do I detect a line collison in LIBGDX?

I am drawing a continuous line using Pixmap. I want to check for a collision / intersection of my line with the already drawn line.
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When would a mesh collider be better than primitive colliders

I have been reading through the Unity Manual and have come across some interesting information about mesh colliders and primitive colliders. It got me wondering if using many primitive colliders would ...