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

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2answers
474 views

Collisions not working as intended

I'm making a game, it's a terraria-like game, with 20x20 blocks, and you can place and remove those blocks. Now, I am trying to write collisions, but it isn't working as I want, the collision ...
-5
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2answers
457 views

two balls stick together in a pool game? [closed]

when multiple collisions occur between balls..sometimes they stick together..mostly in cases of either of the balls having high velocity..can somebody explain pls
55
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9answers
5k views

How to avoid circular dependencies between Player and World?

I'm working on a 2D game where you can move up, down, left and right. I have essentially two game logic objects: Player: Has a position relative to the world World: Draws the map and the player So ...
33
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6answers
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 ...
12
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1answer
5k views

How can I define a complex collision area on top of a tile map?

As many people recommended, I am using Tiled map editor to create a map for my game and it's great particularly because libgdx framework also provides with API for maps from Tiled. I understand I can ...
17
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7answers
3k views

How do I make A* agents avoid other agents?

I'm implementing a multi agent A* algorithm on a tile map. Agents move only in the X and Y axes. I avoid collisions between them by checking where the others are when calculating paths. It works fine ...
6
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2answers
2k views

Triangle-triangle continuous collision detection

I am making a 3D game engine and I use continuous collision detection. I am using Sphere-Trees to cull primitive collision checks to a minimum. However, I'd like to perform continuous ...
16
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5answers
9k views

Collision Resolution

I know quite well how to check for collisions, but I don't know how to handle the collision in a good way. Simplified, if two objects collide I use some calculations to change the velocity direction. ...
9
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3answers
5k views

Collision detection with curves

I'm working on a 2D game in which I would like to do collision detection between a moving circle and some kind of static curves (maybe Bezier curves). Currently my game features only straight lines ...
9
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2answers
3k views

Collision detection and response in an Entity System

More fun with an ES... Currently, I have a few systems: Renderer (Renderable attribute, Transform attribute) Motion (Movable attribute, Transform attribute, Renderable attribute [for bounding ...
17
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2answers
5k views

How do I test if a circle and concave polygon intersect?

I have a polygon (sometimes convex, but often concave), and a bunch of circles with different radii. How can I find out if a circle is intersecting/overlapping with the polygon? I could split my ...
13
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5answers
2k views

Optimizing collision engine bottleneck

If this is your first time on this question, I suggest reading the pre-update part below first, then this part. Here's a synthesis of the problem, though: Basically, I have a collision detection ...
10
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2answers
469 views

Falling Blocks and complex shapes

I currently have a simple Tetris-like game and have come across a problem I cannot solve. Unlike Tetris where there is a single falling shape, I have multiple, potentially interlocking shapes that ...
10
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2answers
2k views

Continuous Physics Engine's Collision Detection Techniques

I'm working on a purely continuous physics engine, and I need to choose algorithms for broad and narrow phase collision detection. "Purely continuous" means I never do intersection tests, but instead ...
12
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1answer
11k views

a simple 2D rectangle collision algorithm that also determines which sides that the rectangles collide?

I initially tried out implementing rectangular intersection, which works well. However, when I have to apply the physics system, such as velocity, acceleration, and directional vectors, I would have ...
7
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1answer
981 views

Creating custom collision map for 2D

I have a 2D level that I have built in my map editor, and I was wondering the best way to create a collision map for it. I have a collision map layer in my map editor, which saves each node (for ...
6
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3answers
7k views

2D Side Scrolling game and “walk over ground” collision detection

The question is not hard, I'm writing a game engine for 2D side scrolling games, however I'm thinking to my 2D side scrolling game and I always come up with the problem of "how should I do collision ...
12
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3answers
5k views

2D game collision response: SAT & minimum displacement along a given axis?

I'm trying to implement a collision system in a 2D game I'm making. The separating axis theorem (as described by metanet's collision tutorial) seems like an efficient and robust way of handling ...
10
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2answers
655 views

Boat passing under a bridge in a 2D tile based RTS

I'm writing a 2D tile based RTS. And I want to add a 'pseudo 3D' feature to it - bridges over the rivers. I havent't start any coding yet, just trying to think how it fits the collision detection ...
8
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4answers
663 views

How do I efficiently check if a point is inside a rotated rectangle?

Part for the sake of optimization, part for learning purposes, I will dare to ask: How can I most efficiently check whether a 2D point P is inside a 2D rotated rectangle XYZW, using C# or C++? ...
6
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2answers
1k views

Correct order of operations in a platformer game loop

I've run into an issue with my Mega Man engine, and the structure of my game loop is making it very difficult to fix. With Rush Jet, or any falling platform, Mega Man needs to stay attached to the ...
2
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3answers
1k views

Coarse Collision Detection in highly dynamic environment

I'm currently working a 3D space game with A LOT of dynamic objects that are all moving (there is pretty much no static environment). I have the collision detection and resolution working just fine, ...
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5answers
2k views

Collision detection logic

Edit 2 In the following picture sprite1 (the red square) is hitting the platform from the left, so: sprite1_rightEdge>platformSprite leftEdge would be true, so I can simply reposition ...
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1answer
2k views

Java/Android pixel perfect hit detection

I am making a game for android which I need hit detection between two objects. The first bitmap I have is a flying superhero, and the second bitmap is anything that he collides with. The superhero ...
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4answers
22k views

Ignore collisions with some objects in certain contexts

I'm making a racing game with cars in Unity. The car has a boost/nitro powerup. While boosting, I wouldn't want to be deviated when colliding with zombies, but I do want to be deviated when colliding ...
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2answers
579 views

Extrapolation breaks collision detection

Before applying extrapolation to my sprite's movement, my collision worked perfectly. However, after applying extrapolation to my sprite's movement (to smooth things out), the collision no longer ...
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2answers
3k views

Algorithm to fit shapes to 2D grid?

Let's say you have an n-by-m grid. Some squares are occupied, some are not. You want to know where in the grid you can fit arbitrary shapes such as to not hit an occupied square. The shapes would ...
2
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1answer
3k 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
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1answer
2k views

How do you implement 2D collision detection?

I would like to know the best or most efficient way to test for 2D collision. I am currently using AABBs, but the problem with this, is that your objects will be hitting things when they shouldn't. ...
2
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2answers
1k views

Projectiles in tile mapped turn-based tactics game?

I am planning to make a Laser Squad clone and I think I have most of the aspects covered. But the major headache is the projectiles shot/thrown. The easy way would be to figure out the probability of ...
11
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2answers
204 views

Combining Many Small Colliders into Larger Ones

I am creating a game using a tile-map made of many thousands of grid squares. At the moment, each square has a square collider on it for checking collisions. However, with many thousands of tiny ...
10
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1answer
1k views

Are there well-known algorithms for fitting a polygon to an arbitrary shape?

I'm using the Chipmunk physics engine to make the levels for a 2D C game. I'd like to be able to fit a polygon to an arbitrary shape to serve as the collision mask. Given a black and white collision ...
9
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5answers
2k views

How to determine which cells in a grid intersect with a given triangle?

I'm currently writing a 2D AI simulation, but I'm not completely certain how to check whether the position of an agent is within the field of view of another. Currently, my world partitioning is ...
8
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2answers
411 views

Platform jumping problems with AABB collisions

See the diagram first: When my AABB physics engine resolves an intersection, it does so by finding the axis where the penetration is smaller, then "push out" the entity on that axis. Considering ...
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2answers
2k views

Identifying quad patterns in a two-dimensional array

In the tech demo I'm trying to make, tetrominoe-style blocks will be placed by the player, at which point the game checks to see if they've made a quad with any existing shapes on the board (a 2D ...
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3answers
648 views

How to handle collisions without ugly conditionals and type checking?

(I asked a similar question, but this one is far more specific). How can I handle collisions without having to do a lot of type checking and if statements? People here suggested that when spotting a ...
4
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5answers
680 views

Collision detection performance problem

Using python and pygame I've built a collision detection system according to the instructions in this YouTube tutorial. This is updated 40 times per second and controls movement and collision ...
4
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2answers
2k views

Sliding collision response

I have been reading plenty of tutorials about sliding collision responses yet I am not able to implement it properly in my project. What I want to do is make a puck slide along the rounded corner ...
4
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1answer
2k views

How can I convert a 2D bitmap (Used for terrain) to a 2D polygon mesh for collision?

So I'm making an artillery type game, sort of similar to Worms with all the usual stuff like destructible terrain etc... and while I could use per-pixel collision that doesn't give me collision ...
4
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1answer
1k views

Are there any good engines for isometric collision detection and platforming?

I've decided to resurrect an old game idea I had years ago. I currently have zero experience with programming, but I'm going to begin studying either C#, Python or both in the near future. The issue ...
4
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4answers
955 views

How to avoid collision detection to enter infinite loop in this case?

I am writing a collision detection system which uses the logic mentioned by Trevor here But I have anticipated a problem which I have shown as a diagram How do we handle this problem?
3
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3answers
3k views

Game physics / 2D Collision detection AS3

I know there are some methods you can use like hittestPoint and so on, but I want to see where my movieclip colliedes with another another movieclip. Any other methods I can use? by any chance does ...
3
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3answers
263 views

Physics System ignores collision in some rare cases

I've been developing a simple physics engine for my game. since the game physics is very simple I've decided to increase accuracy a little bit. Instead of formal integration methods like fourier or ...
3
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2answers
2k views

3D Ball Physics Theory: collision response on ground and against walls?

I'm really struggling to get a strong grasp on how I should be handling collision response in a game engine I'm building around a 3D ball physics concept. Think Monkey Ball as an example of the type ...
2
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1answer
10k views

How do I make a game tick method?

I've seen in some other simple 2D games that a "tick" method is used to sync game logic and graphics rendering. My main reason for using this is due to my collision detection malfunctioning, since ...
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1answer
474 views

Detailed Modern Opengl Tutorial? [duplicate]

I am asking for a specific modern opengl tutorial. I need a tutorial that does not skip to explain any lines of code. It should also include different independent objects moving/rotating (most ...
11
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2answers
572 views

How do I make good guy attacks only hit bad guys and vice versa?

My game has many different type of good guys and many different type of bad guys. They will all be firing projectiles at each other but I don't want any accidental collateral damage to occur for ...
10
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4answers
2k views

Collision rectangle response

I'm having difficulties getting a moveable rectangle to collide with more than one rectangle. I'm using SFML and it has a handy function called intersects which takes 2 rectangles and returns the ...
7
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4answers
4k views

How do I find the intersection of two lines

I have a bounding box on my character, its position in the previous frame an the current frame. The bounding box is axis aligned. My character is running around inside a cave, I have a list of ...
7
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3answers
727 views

Your recommendation for path construction from a single background image?

So I currently have my background as a single PNG and some obstacles (like blocks as part of that PNG). In order to create a path, I currently store pixels above a unique green color (my hill) and use ...