Tagged Questions

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

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2
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2answers
631 views

How to simulate wind in 2D

for a 2D scenario, I wanted to have a fan blow at an object and make it move with the "wind", how can I simulate the wind under these circumstances?
1
vote
2answers
241 views

How to resolve a collision at the border between two colliders?

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 ...
0
votes
1answer
88 views

How should I detect collisions with objects on a “timeline”?

I'd like to replicate this game's mechanic of the player smashing walls with a precise timing to a background rhythm. How should I check when each wall should be broken? Does the player animation use ...
1
vote
1answer
120 views

Collision between player and heightmap

Im programming a small project, an opengl height map. It is build of triangles, which points are fit to the right y position (read out of an image). The player is represanted by a cuboid. (p1, p2, ...
2
votes
2answers
153 views

Pathplanning A* Getting stuck in wall

I'm having a problem with my pathplanning. I can plan a path and make my character follow it, that's not a problem but then i plan a path around a wall it takes the shortest way as A* suggests, which ...
2
votes
4answers
85 views

Identifying groupings of objects

I have a cloud of objects, each with a 3D position, and I want to pick out tight groups of these objects. Specifically, I want to find all objects which form a grouping of radius r within a large ...
5
votes
1answer
155 views

Self colliding cloth physics

I've previously simulated cloth using Verlet integration but couldn't successfully get the cloth to collide with itself in an efficient way. The reason being is because I used a brute force algorithm ...
1
vote
1answer
173 views

Trigger for Melee-attack not working

I'm currently trying to add a melee-slash attack to my Sidescroller. For that I decided to to have an invisible box-colliders infront of my character. My idea is to activate it when the attack-key is ...
1
vote
1answer
84 views

Different bounding volumes for culling and collision detection

Should an object in a 3D-engine use different bounding volumes for collision-detection (broad-phase) and culling? Basically class renderBounds and class physBounds versus class boundingVolume? Each ...
2
votes
1answer
134 views

Is there a way to view all colliders in a unity project at runtime (after the game have been deployed)?

I'm have created a small Unity project but physics has weird behavior (bug). Unfortunately it only happens on some specific hardware (after build), not on development machine. I don't know what is ...
1
vote
3answers
118 views

Removing something on Collision?

I have my collision detection code working so how would I tell my HealthPickup to disappear when my Player collides with it? I haven't played around with it yet but I think I may have to somehow ...
0
votes
2answers
382 views

Java collision detection and player movement: tips

I have read a short guide for game develompent (java, without external libraries). I'm facing with collision detection and player (and bullets) movements. Now i put the code. Most of it is taken ...
0
votes
0answers
21 views

Resolving penetration by adding the penetration vector to the colliding entities

During collisions I find the penetration vector of the colliding entities (using SAT). Should I add it to the position of entityA, of entityB, or to both?
1
vote
1answer
70 views

Resolving penentration after collision using Separating Axis Thereom

I implemented collision detection in my game using SAT. The detection works, but I'm trying to use the algorithm to figure out the penetration vector of the two OBBs and push them apart (before doing ...
0
votes
1answer
48 views

How to resolve OBB collision penetration?

I would think this is a common issue, but I couldn't find an answer that helped me. Help would be appreciated. In my game I have rectangular objects. They have rotating bounding box, aka not AABB but ...
1
vote
0answers
51 views

How to Calculate K-Dops Faster

Ok so I have my general understanding of K-Dops for collision detection. I understand how to calculate them. I also understand the super slow way of recalculating them. Example: I have a simple ...
2
votes
2answers
195 views

XNA - Making 2D Hexagons Connect With Each Other

Hey so I'm working on a top-down 2D strategy game in XNA, and the tiles are hexagons. I can't have a grid because of the game mechanics, so everything has its own location, and every tile object is ...
17
votes
7answers
2k 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 ...
5
votes
2answers
325 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 ...
3
votes
1answer
206 views

How and when to choose which objects to run collision tests on?

This might be problem with plenty of good solutions, but it's all not very clear to me, so I though I could ask and probably get some good hints. I'm having trouble figuring out how to handle ...
0
votes
1answer
93 views

Collision detection recommendations [closed]

I am currently developing a prototype game for mobile devices in which the user will see several objects on the screen and will have to touch them one by one in the correct order to win. I guess it ...
0
votes
1answer
53 views

Collision detection in ruby

I'm making a simple pong game in ruby. I did the collision detection this way: def collides_with(player) ((@x + @image.width >= player.x) && (@x <= player.x + ...
-2
votes
2answers
111 views

How to avoid tons of `instanceof` in collision detection? [duplicate]

Consider a simple game with 4 kinds of entities: Robots, Dogs, Missiles, Walls. Here's a simple collision-detection mechanism in psuedocode: (I know, O(n^2). Irrelevant for this question). ...
0
votes
2answers
131 views

Updating entities in response to collisions - should this be in the collision-detection class or in the entity-updater class?

In a game I'm working on, there's a class responsible for collision detection. It's method detectCollisions(List<Entity> entities) is called from the main gameloop. The code to update the ...
0
votes
2answers
187 views

How can i get almost pixel perfect collision detection in a multiplayer game?

I'm currently working on a multiplayer game for iPhone. The problem i have, as with all multiplayer games, is that the other user will always see everything at a non-constant delay. The game I'm ...
0
votes
2answers
128 views

Without using a pre-built physics engine, how can I implement 3-D collision detection from scratch? [closed]

I want to tackle some basic 3-D collision detection and was wondering how engines handle this and give you a pretty interface and make it so easy ... I want to do it all myself, however. 2-D ...
3
votes
2answers
222 views

How should I choose quadtree depth?

I'm using a quadtree to prune collision detection pairs in a 2d world. How should I choose to what depth said quadtree is calculated? The world is made mostly of moving objects1, so the cost of ...
0
votes
0answers
27 views

Turning on collision crashes game

I am getting a null pointer excecption to both my sprite and level. I am working on my mob class, and when I try to move him and the move function is called, the game crashes after checking collision ...
2
votes
2answers
90 views

Is an extra collision-mesh for level-data worth the hassle?

What is the optimal approach for collision-detection with the environment in an 3D engine (with triangle mesh based geometry, no bsp)? A) Use the render mesh [+] no need for additional work for ...
2
votes
1answer
197 views

libgdx collision detection / bounding the object

i am trying to get collision detection so i am drawing a red rectangle to see if it is working, and when i do the code below in the update method. to check if it is going to work. the position is not ...
-1
votes
1answer
117 views

Adding a small slide when player releases left/right key

The aim is for the player object to slow down and stop instead of just stopping dead. The following codes works ok when the player is not jumping, but gets stuck in an object if the player is in the ...
1
vote
1answer
79 views

Point in Polygon, Ray Method: ending infinite line

Having a bit of trouble with point in polygon collision detection using the ray method i.e. http://en.wikipedia.org/wiki/Point_in_polygon My problem is I need to give an end to the infinite line ...
0
votes
2answers
141 views

2D Tile Collision free movement

I'm coding a 3D game for a project using OpenGL and I'm trying to do tile collision on a surface. The surface plane is split into a grid of 64x64 pixels and I can simply check if the (x,y) tile is ...
0
votes
3answers
310 views

How to optimize collision detection

I am developing a 2D Java Game with LibGDX. This is what it kinda looks like (simplified): The big black circle is the player, which you can move by tilting the smartphone. The red circles and blue ...
0
votes
1answer
56 views

From where does the game engines add location of an object?

I have started making my first game( a pong game )with ruby (Gosu). I'm trying to detect the collision of two images using their location by comparing the location of the object (a ball) to another ...
3
votes
3answers
968 views

Detect collision from a particular side

I'm making a platform sidescrolling game. All I want to do is to detect if my character is on the floor: function OnCollisionStay (col : Collision){ if(col.gameObject.tag == "Floor"){ ...
1
vote
0answers
43 views

Bullet Physics ConvexDecomposition?

I've looked at Bullet Physics ConvexComposition Demo and would like to implement that in my game but the code is so undescriptive and it's hard to understand what is going on. Would any of you people ...
0
votes
1answer
111 views

Using Bullet physics engine to find the moment of object contact before penetration

I would like to use Bullet Physics engine to simulate the objects in 3D world. One of the objects in the world will move using the position from 3D mouse control. I will call it "Mouse Object" and ...
0
votes
1answer
86 views

Load Meshes with Bullet Physics

I just started implementing some physics in my game with Bullet Physics and I was just wondering how would i use bullet physics to load in meshes. For my for DirectX I load in x files into a ...
0
votes
2answers
542 views

Libgdx detect when player is outside of screen

Im trying to learn libGDX (coming from XNA/MonoDevelop), and I'm making a super simple test game to get to know it better. I was wondering how to detect if the player sprite is outside of the screen ...
2
votes
2answers
173 views

Sprite Kit - containsPoint for SKPhysicsBody?

I have a ball bouncing around the screen. I can pick it up and drag it onto a "bucket". When my touches finish, I use the containsPoint function to check and see if I have dropped the ball onto the ...
-1
votes
1answer
148 views

simple collision detection with box2dweb

im beginner in box2dweb that version of box2d for javascript i wrote simple gravity system and i want to detect the collision between the box and the ground , when the falling box hit the ground ...
0
votes
1answer
73 views

Bounding Box Collision Glitching Problem (Pygame)

So far the "Bounding Box" method is the only one that I know. It's efficient enough to deal with simple games. Nevertheless, the game I'm developing is not that simple anymore and for that reason, ...
1
vote
2answers
135 views

How to solve the overlap between a rectangle and a circle that collide

I have two figures - a circle and a rectangle and i have a method that checks whether the two figures collide. How to prevent them from overlapping during collision?
1
vote
0answers
114 views

Collision detection 3d rectangles using SAT

This question builds on a previous post asked by griffinHeart nov 2012. See link below. How many and which axes to use for 3D OBB collision with SAT Refering to the explanation/answer by Ken. What ...
10
votes
2answers
364 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 ...
1
vote
0answers
31 views

Any tips on developing an RTS unit movement collision? [duplicate]

so I am developing an RTS and I am a little stuck at this. I am not talking about pathfinding algorithms like A*. The problem is moving units in bulk and their collision along the way. Can anyone give ...
1
vote
3answers
77 views

How do I find the intersection of a ray and a cylinder?

I'm looking for the algorithm to find the intersection (or lack of) between a ray and a cylinder. I have rotating coin like objects in my game world and need to check for a collision on that object. I ...
1
vote
2answers
225 views

Object goes straight through game object without colliding

The "shot" is supposed to collide with the left bumper and then be destroyed, but the shot goes right through it. Both objects have a box collider. The following is the code I am using: #pragma ...
0
votes
1answer
99 views

Collision intermittently fails when multiple bullets on screen

I'm building a very simple Java game where a player rectangle fires bullet rectangles at enemy rectangles. When a single bullet is on screen, it always correctly collides with enemies. When multiple ...