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

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Bounding Box not rotating based on draw rotation (Java)

In the process of developing a 2D game and am having some issues with translating coordinates on rotation. The object being rotated is a sword that is attached to the player. The player currently ...
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1answer
624 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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3answers
238 views

Is there algorithm for boxcasting or thickray casting?

I am not sure what the correct name is called but here is my problem: I have implemented a casting ray function that works as expected. However, because I am using a loose grid structure, (ie, objects ...
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2answers
152 views

How to avoid checking the same triangle twice in collision detection with spatial hashing

I'm implementing a spatial hashing system to speed up my collision detection, but I've run into a problem. Since a triangle can be hashed into multiple buckets, how do I ensure that I don't check the ...
2
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1answer
799 views

Getting child collider when collision occurs in compound object in unity3d?

I have a compound object. The parent of the compound object hierarchy has a script that is listening to the OnTrigerXXX callbacks of the children. When this compound object collides with other objects ...
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0answers
61 views

Manual response when 2 shapes made of rectangular volumes collide

I have 2 compound objects made of rectangular blocks. One of them (the one that is moving) has a script that listens to OnTrigger callbacks. What I need is to position the moving compound object on ...
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1answer
405 views

Triangular Mesh Collision/ Resolution

I've been trying some different approaches for collision detection and now I want to try to implement simple Mesh-Mesh collision detection for triangular meshes. I'm wondering if I'm on the right ...
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1answer
364 views

How to implement 2d collision detection that is immune to low framerate and fast movement? [duplicate]

I am trying to implement my own collision detection for a 2.5d voxel style platformer using Three.js. I have a problem with my implementation - if the framerate is too low or the character is moving ...
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2answers
341 views

Jelly ground collision

For fun I am trying to replicate the mechanics from The Floor is Jelly. So far I have successfully created "jelly islands/blocks" which are represented by an array of points and then drawn by using ...
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1answer
162 views

Collision detection algorithms with images (2-Dimensions)

Lately, I have been researching different Collision methods, how to deal with multiple collisions and different types of bounding shapes, circles, rectangles, polygons and ellipsoids. Some common ...
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1answer
422 views

Sweep and prune vs quad tree when all objects are dynamic (moving)

As I understand it there are 3 popular strategies for spatial partitioning: sweep and prune, quad/oct tree and uniform grid. Uniform grid is problematic for me because I have not set an upper limit on ...
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0answers
364 views

Should I use Box2D for collision-detection only (not simulating physics)? [closed]

I'm using Box2D only to check collisions and for no physical simulation. I create bodies (and shapes for them) and use my own code to move them, by setting their velocities and positions every frame. ...
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1answer
595 views

LibGDX Bounding Rectangles

I'm creating some rectangles surrounding my sprites for my player and bullet class to detect collisions with the overlaps method in Intersector class of LibGDX. I have a question: When I instantiate ...
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0answers
194 views

2D Distance Field as collision handler method

Pixeljunk Shooter has really cool fluid simulation. I found the dev's video explaining what they did. Here I understand that it is particle based simulation Smoothed Particle Hydrodynamic I can ...
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0answers
59 views

Load character instead of load level

I have some trouble finding out how I can load my character at the start of the level, instead of resetting the whole thing. The game mechanics are quite straight forward; don't touch the walls. If ...
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0answers
46 views

How do I apply Farseer Physics Engine Collision on my image? I tried it on my codes and it is not working

How do I apply Farseer Physics Engine Collision on my image? I tried it on my codes and it is not working. PoolGameSingle poolgame = new PoolGameSingle(); var cue = poolgame.CueStick; ...
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1answer
99 views

Set a component on root gameobject for working all the children

I have a enemy which has ragdoll. So it has a few child object and each child has own collider. I dont want to add script for every child for just OnCollisionEnter function. All of them will work ...
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1answer
902 views

How do I make a sprite collide with walls in pygame?

I've been trying to create a collision detection between the player (Blue), and the walls (Green), but the player can just move through the walls. I made it so that every collision is printed in the ...
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0answers
94 views

Collision detection in 3d

what is the simplest algorithm for collision detection that respects the following requirements: The collision is only between cubes that are always aligned with the axis of the world (not rotated). ...
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0answers
92 views

Drag and drop in Flare3d [closed]

Now iam working on drag and drop prototype in flare3d.I have a f3d object and have different boxes to place the parts of the f3d objects . when i drag the parts of f3d object towards the boxes,if ...
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4answers
4k 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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2answers
103 views

Issue implementing proper collision in XNA Game Studio 4.0

I am building a game in XNA 4.0, where a player moves about a 2 dimensional (vertical perspective) map consisting of blocks. My issue is creating proper collision between the payer and the blocks ...
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1answer
130 views

Why Is My AABB Collision Detection Not Working

I am going to be making a 3D game and I need to be able to test for accurate collision. I was able to get bounding sphere collision working (too inaccurate to be used for the whole game), but AABB ...
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1answer
517 views

How do I calculate the distance between a point and a rotated rectangle?

This question is similar to another one about axis-aligned rectangles. However, I specifically want to calculate this for rotated rectangles. I have a rectangle with a (cx, cy) for the center ...
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1answer
567 views

Why is OnCollisionEnter2D called when it's layer's collisions are being ignored?

I'm sure this is down to my lack of understanding of the unity physics system. I'm trying to implement a simple one-way platform for a 2d game and have got stuck on creating a reliable way to let the ...
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2answers
223 views

Find a position within one radius, but outside other radii

I have an Object A which will attempt to stay within a certain distance of another Object B. I would like Object A to also try to stay outside a certain distance of one or more other Objects R. The ...
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0answers
152 views

How do I detect collisions between a particle-based net and a ball?

I've implemented a net using Verlet integration and many points connected with constrains; like this demo, but in 3D. I want to implement collision detection between this net and a ball (like in a ...
2
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1answer
516 views

Collision detection between 2 irregular shapes

I need to implement a collision system for a vertical-shotter and the bullets can have any type of shape; i've implemented the shape class with an array of choords and an array of lines which have the ...
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2answers
289 views

How do I raycast to detect which hexagonal tile was clicked?

I want to detect the hexagonal tile a unit is on upon clicking on the unit. I was thinking of using a ray cast I can't get it to work. I'm trying to get the raycast to shoot from the bottom of the ...
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1answer
424 views

How do I implement melee hit boxes for a top-down game?

For a 3D top-down game, how should I handle collision in melee combat? My game has no targeting system, so I can't use a simple distance check between attacker and target. What I am thinking is have ...
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0answers
35 views

How can I have an RPG character redirect / glance off stationary objects and keep going? [duplicate]

I am attempting to create an effect in a game that is identical to the effect I've shown in the attached gifs. Essentially, the character, when they are running or walking and hit an object that is ...
2
votes
2answers
100 views

How to preserve topology for penetration correction?

I have a sorted list of blocks - some may overlap some may not. Each block has an ideal starting position and may be constrained to one axis. There are no velocity or acceleration or other forces ...
2
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1answer
427 views

Minkowski Portal Refinement collision detection algorithm

Preface: While I was learning the basics of collision detection, I read in various places that the SAT and GJK algorithms don't natively return contact points. So I decided to research the MPR ...
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1answer
193 views

2D physics collision/gravity problem?

I'm using Love2D and my own physics engine to create a 2D platformer. Y collision works fine, but X collision... well, it's a bit buggy. When I move off of a small platform I've created, I fall but it ...
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0answers
330 views

A problem with collision when a sprite changes size (Phaser framework) [closed]

I have a sprite in my game that changes size at certain points in the game. It changes size via the sprite.body.setSize method. Unfortunately, it seems that the sprite is unaffected by objects that it ...
3
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2answers
4k views

Detecting mouse clicks in Unity UI Beta

I want my game script to detect mouse clicks everywhere on my screen, except one corner where I have a pair of buttons to control the sound and will be handled separately. To help identify this ...
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1answer
130 views

Collision detection across multiple components

I have been reading this article: http://gameprogrammingpatterns.com/component.html which describes how a game object should be constructed out of components. It also encourages the decoupling of ...
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1answer
404 views

Animation-based Collision Boxes

Background I'm currently working on a top-down 2D game, roughly similar to something like Zelda for the SNES. Certain game entities such as the player or a typical enemy will consist of multiple ...
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2answers
1k views

Implementing one-way platforms in Chipmunk

I am making game in cocos2d-x, but it's the first time I am using a physics engine i.e. Chipmunk. (It's built-in to cocos2d-x.) I want to make a one-way platform: When my character jumps into a ...
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1answer
231 views

Unity Guitext object always triggering a collision - 2D

I have a guitext object which I can drag. I have attached a 2d rigid body. I have also attached the collider with the following code: void setCollider() { Rect box = ...
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0answers
110 views

Very strange trigger behavior in Unity2D (4.5)

I am developing 2d platformer and I've faced with a very strange triggers behaviour in Unity. I have made the enemy that can throw objects into main player. So I have made two empty GameObjects with ...
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1answer
65 views

Trying to implement bounding box collision

I've been trying to do collision detection using the Intersects() function with two rectangles. I've got a player and multiple enemy's. When the player intersects with an enemy a bool var is set to ...
0
votes
1answer
258 views

SHMUP: who's in charge of collision detection? [duplicate]

Simple design question here: In a Shoot'Em Up, where you often have to deal with hundreds of bullets / missiles / weird flying stuff, who's in charge of detecting collisions? The weapon or the ship? ...
3
votes
3answers
270 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 ...
2
votes
1answer
93 views

Pair collision detection on quadtree

I'm planning to use a quadtree for optimizing collision detection. But this quadtree can handle only one type of objects (so I used a base class for my objects). If I use double dispatch after two ...
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vote
0answers
128 views

Collision detection implementation suggestions

I'm working on a simple 2D game involving a rotating octagonal ring where a sphere sprite moves up/down avoiding objects as the ring rotates faster and faster. I'm having a difficult time with the ...
2
votes
2answers
127 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 ...
0
votes
1answer
100 views

Crafty - How to get the id of the collision element?

As the topic says, I want to know how to get the ID of an active colliding entity. My Player Entity is called with Crafty.e("Player") Please notice, that I do not want the ID of my Player Entity. ...
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2answers
456 views

How to do collision detection on marching cubes terrain?

I'm writing the physics part of my game engine. The world uses the marching cubes algorithm on a 3d perlin noise to make the terrain. How do I do collision detection on the resulting mesh? I can't ...
4
votes
2answers
2k views

Getting a pixel of Sprite at the cursor position in Unity

Summary: I've been trying to figure out a way to use simple box colliders as a nice and efficient "first pass" collider. For the "second pass", I want to check that the area clicked has an alpha value ...