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

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248 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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1answer
287 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 ...
3
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2answers
541 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 ...
3
votes
1answer
507 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 ...
2
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3answers
770 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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2answers
357 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
644 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. ...
2
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1answer
783 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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1answer
793 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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1answer
164 views

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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1answer
181 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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3answers
3k views

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
454 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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1answer
977 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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0answers
162 views

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
451 views

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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1answer
3k views

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 ...
0
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1answer
2k views

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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3answers
1k views

Collision detection optimization for a top down shooter

I'm relatively new to game development and have been trying to learn how collision detection is coded. I mostly work with Actionscript 3, but I'm learning C++ on the side. I've been wondering how "...
0
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1answer
479 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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1answer
294 views

Roguelike 2D Collision Detection

I'm just a normal guy trying to do some basic collision detection but I suck at it. I either get stuck in a wall or I go in reverse in the wrong direction trying to update the player position to a non ...
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3answers
3k views

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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2answers
2k views

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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1answer
1k views

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 ...
4
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1answer
1k views

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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2answers
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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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1answer
2k views

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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2answers
2k views

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 ...
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3answers
4k views

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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4answers
5k views

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 ...
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1answer
1k views

2D platformer multiple rectangle collision cause jitter

I posted this question two weeks ago: 2D platformer corner collision and I implemented NoobsArePeople2's solution. Problem is, when player intersects two rectangles that are inside each other, he ...
2
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1answer
153 views

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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2answers
396 views

Tile map collision is not working properly

I am having problems setting collision between my sprite and the tiles. I have only done the code for colision for moving upwards but some places on the map it moves up and some places it doesn't. ...
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2answers
628 views

Collision detection - make sure the player touches the object exactly

I know this is really something I should be able to figure out on my own, but a solution is evading me. Okay, here are a few relevant parts of my code. bool Game::Col(int x1,int y1,int w1,int h1, ...
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3answers
4k views

Unity, changing gravity game & stopping character when he hit a wall

i am currently working on a 2d puzzle game in the unity engine. One of the aspect of this game is the possibility to rotate the level of 90°. It also rotate the gravity. The main character is not ...
2
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2answers
140 views

Rendering after interpolating, renders inside/outside other objects

So, we're working out our interpolated render-coordinates during our render call and it's doing a fantastic job of smoothing everything out. All is great and collision detection is working to a ...
2
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1answer
296 views

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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2answers
636 views

Fast 2D collision detection in an unbounded space

I'm trying to do collision detection on a large number of entities of greatly varying size in an unbounded space. The entities are circles, so it's relatively easy to check if two are colliding. ...
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votes
2answers
990 views

Tile based map and collision; getting stuck

I'm trying to make my character move around a tile map with collisions. Everything works fine except for one thing. I show you a picture with the problem: http://i.stack.imgur.com/ZWI7x.jpg That is, ...
2
votes
1answer
809 views

Checking Collisions In 2D Platformer With Tiles

My team and I are developing a 2D platformer with C++/SDL/OpenGL, and we already defined a collision system, but we have a problem checking collisions with the tilemap. The tiles of the tilemap are ...
2
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4answers
5k views

How do I detect pixel-level collision using andEngine?

I'm developing a game for Android using andEngine, and I need to detect collisions only when two objects visually collide (not in blank space of the image). In J2ME, I'm able to do that using ...
2
votes
1answer
1k views

Collision Detection for a 2D RPG

First of all, I have done some research on this topic before asking, and I'm asking this question as a mean to get some opinions on this topic, so I don't make a decision only on my own, but taking ...
2
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3answers
3k views

2d Collision detecton axis aligned boxes

I have recently run into some trouble with my collision detection. My game is composed of a map made out of axis aligned squares. The player has an x and y velocity, and I want to know how I can find ...
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1answer
2k views

How can I cancel a contact in a b2ContactListener?

To know when contacts happen we can derive from b2ContactListener and implement our own solution which is great. I'm wondering is there anyway we can cancel a contact, that is to say when we hit begin ...
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1answer
1k views

Triangle-Triangle Intersection Code

Does anyone have experience implementing this triangle-triangle intersection code that I found online? I don't understand it. I made a post on Stack Overflow about this and got the advice that: ...
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vote
1answer
553 views

How do I get the axes for SAT collision detection

In SAT collision detection how do I calculate the axes for projection?
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vote
0answers
185 views

Farseer Physics EndContact events don't fire for all registered delegates

Here's my situation: I have several objects that contain a body and a fixture. They are set to sensor = true; atmosphere = BodyFactory.CreateCircle(world, atmosphereRadius / Level.METER_IN_PIXELS, ...
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2answers
655 views

Randomly spawning bitmaps on cnvas

I need some ideas in order to finish algorithm. I'm randomly placing objects (bitmaps) on canvas without overlapping. Time needed to finish it is my problem. When I need to spawn for example 80% of ...
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2answers
114 views

How can I detect a perfect passageway for collision detection?

The problem is when I move diagonal it moves fractions of units and therefore my coordinates might be a fraction of a unit say (40,400) might be actually (40.12,400.40) but another problem is my pink ...
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1answer
257 views

How can I know in which direction 2 balls will go in billiard game?

When a ball is struck, how can we know in which direction both balls will go when ball is struck? I know the angle at which the ball strikes the other ball matters, but how can we calculate that angle?...