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

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360 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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215 views

How do I compute the angle between a pixel on an irregular curve and a circle colliding with it?

I'm building a custom physics engine to accompany a level-editor. This image shows how the level-editor outputs levels: Now, some explanation is in order. The curve is defined by the red points. ...
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560 views

Why does my RigidBody collision fail depending on which entity is moving?

I am working on a UDK project and have a collision problem. I have a Crate which is a kActor with RigidBody physics and my player who is a Pawn. When my player moves and collides with the crate, the ...
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90 views

What is the most effective way to create a set of collision points for an aribitrary mesh?

In my project I am working on automatically deforming an arbitrary mesh with respect to another arbitrary mesh, within the context of user generated content, similar to this deformer being developed ...
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19 views

How do I find the intersection point from the Expanding Polytope Algorithm?

I've successfully implemented a 2D version of the GJK and EPA algorithms which gives me correct collision information, including collision normal and penetration depth. What it doesn't give me ...
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43 views

Using Box2D in LibGDX, is there a reason a fixture set to be a sensor would only -sometimes- detect a collision?

I am working on a 2D game in LibGDX. Currently, I am testing interactions between a player's weapon and enemies - in particular, a sword and an enemy monster. The player has a hurtbox and the sword ...
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54 views

Collision Detection Between 3 or More Objects

Say I have a 2D grid of particles, and I wanted to find out if any of them were colliding. In my head I have come up with a system where you check every possible location for each particle in that ...
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36 views

Is there a way to rotate an Ellipse in libGDX for collision detection purposes?

I'm trying to avoid having multiple overlapping Circles for a UFO-shaped sprite. Two Ellipse objects will perfectly cover the shape of my UFO, but I want to tilt/rotate the UFO when flying left and ...
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416 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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53 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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145 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 ...
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115 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 ...
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148 views

LibGdx Triangle Collision

I'm back with another question. I'm trying to get a collision between an actor and a sprite. With the actor, which only moves upwards and downwards, I've got no problem since it's shape is a ...
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59 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 ...
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0answers
50 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 ...
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168 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 ...
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60 views

Setting up 3d Collision for Primitive shapes

Im having some trouble understanding how to set up collision detection between my first person camera and my primitive shapes which are made using the vertex buffer. Do i give my camera a boundingBox ...
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85 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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109 views

Collision Avoidance/Steering around moving obstacles

I've done a decent amount of research and I've read up on pathfinding algorithms and such, but I can't seem to find anything to do with the mentioned behaviors when moving around obstacles that also ...
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127 views

Speeding up point-in-polygon for Python

In researching collision detection methods for non-Rect-like objects I came across point-in-polygon -- specifically, the even-odd rule. The one presently on Wikipedia claims it is written in Python, ...
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389 views

How to identify whether the boundingvolume intersects with walls or floor when it doesnt return normals?

My game in jMonkey is the kind that use will have to place objects in a scene (which consist of walls and slabs and floor). All my models are centered at origin. When the user click a point I use ray ...
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241 views

beginContact triggered more than once on some objects

Short version: It looks like beginContact is detecting continuous collisions. I'd like to avoid that. Long version : I use Box2Dweb to write a 2D platformer. It's my first game using this lib, and, ...
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162 views

Aiming with a crosshair with a lot of polygons/triangles

I'm working on a 3d kindof game where I'll eventually be able to modify the shapes present in the environment by pulling their faces with a crosshair. The thing is that I don't know how to achieve ...
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166 views

scale rotating boundingbox

I want to use basic rectangular collision detection. I have a rotating sprite and a method that calculates the bounding box every time in the Update() method. I simply check for intersection between ...
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226 views

How can I implement collision for a “pseudo-3D” game?

I'm looking for high level implementation details, not specifics. I've worked with bounding boxes before in some 2D games, but I'm currently tackling a "2D + depth" (2.5D?) style game along the lines ...
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266 views

Sketchy results from ray-plane intersection code

I've set up a demo with simple first-person controls using C++ and OpenGL, and it seems to work reasonably well. My goal is this: when the player looks at a plane and clicks the left mouse button, ...
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331 views

iOS cocos2d - sprite gets stuck in collision detection

I'm developing a top down game in cocos2d and I have collision code that checks collisions between enemies and the player so that they don't go through each other. The code seems to work but the ...
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1k views

Why do restitution values less than one still cause infinite bouncing in Box2D?

I'm currently trying to implement basketball bouncing into my game using Box2d (jBox2d technically), but I'm a bit confused about restitution. While trying to create the ball in the testbed first, ...
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236 views

Detect Sprites, they are in Shape or Not which random draw in Cocos2d

I have searched a lot on web and found some of help ful links as exact my question. Link 1 Link 2 But still i am not success to achieve this, i have done some of code lines, as like draw line by ...
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50 views

Getting collisions with equal values in Sweep and Prune

When sorting an (incremental and persistent) SAP, you generally move extremas left until you run into a smaller/equal extrema, gathering collisions along the way. However, that results in the ...
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970 views

Unity3D: collider performances on mobile iOS devices

I'm experimenting with Unity3D and colliders. Unfortunately I still don't have Unity Pro version and I can't use the profiler. Consider the following situation: mobile devices (ios, iphone 3GS). an ...
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627 views

What is the best way to implement collision detection using Bullet physics engine and a track generated from a curve?

I am developing a small racing gam, the track is generated from a curve. As said above, the track is generated, but not infinite. The track of one level could fit with no problem in memory and will ...
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209 views

Updating physics for animated models

For a new game we have do set up a scene with a minimum of 30 bone animated models.(shooter) The problem is that the update process for the animated models takes too long. Thats what I do: Each ...
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168 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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435 views

3d collision detection on non flat surface

i am developing a game which needs an accurate collision detection algorithm, when a object travels down a slope which isn't flat. To be more precise i need to simulate a skier who travels down a ...
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13 views

JBullet - Two RigidBodies will not collide

I am adding two ships into my collision world. (The green dots are the collision shape (an ObjectArrayList) that I am passing to the ConvexHullShape) However they don't seem to collide. In fact, ...
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42 views

2D Collisions side detection

I've been working on a 2D collision system for my games and came up with something. I need the collisions to check against any sized rectangles. I understand how to check for overlapping rectangles ...
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32 views

(LibGDX/JAVA) How can I get a rectangle to rotate with this pendulum so I can start detecting collisions?

One of the objects in my game is a pendulum that swings in a semi-circle. This is done by having an update() method like this: public void update() { angleAcceleration = +1.81 / length * ...
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38 views

Unity material is missing after compilation

I have a piece of code that signals the player that a projectile has hit its target. Everything works fine during the playmode, however after I compile it, it acts as if there was a missing material. ...
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37 views

Creating a custom collider shape in unity, and performance concerns

I want to create a custom chaped collider in unity to create point-defense triggers for objects. I have a spherical collider that triggers for attacking objects that enter it already. However I want ...
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43 views

My “puck” model object falls right through the “table” model in jmonkeyengine

So I am trying to learn Jmonkey, I have understood everything so far, and I thought i understood how to make objects solid, so things cant go through each other. When i created my Collision shapes, I ...
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32 views

Collision Detection acting weird

I started learning programming in java. and I've decided to make a simple game but, got a problem in collision detection. The problem here is that the collision detection is sometimes not working. ...
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0answers
47 views

resolving per pixel collision issue

In space invader, I'm doing bullet to barrier intersection using rect to rect, then I'm testing the first bullet's impact pixel, if it's green I blast a circle, if it's black, it continues travelling. ...
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22 views

Colliding wiith a smooth line of blocks

I'm having a strange problem. I'm creating a 2D platformer, and creating the gameplay map by reading a csv file and placing prefabs of the appropriate type on map. One part of the map is a simple ...
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0answers
43 views

Does unused 2D colliders in Unity affects performance? Is an Edge Collider more performance friendly than BoxCollider2D?

I am using a lot of gameobjects for my platformer that uses BoxCollider2D component to make the scene floor. But only an a selected set of gameobjects actually have some interaction with the player, ...
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0answers
36 views

Sprite collision Rectangles LibGDX

I have a big problem with my sprite top collision. Here ismy constructor public CoolGuy(){ full = new Rectangle(0, 0, 50, 98); bottom = new Rectangle(0, 0, 50, 15); top = new Rectangle(0, ...
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51 views

How can I handle ball interaction with lanes in a pinball game?

In a pinball game, how can I handle collision or constraints on the ball for convincing movement on those highway rails/tracks? I assume using physics and a mesh collider would not work, even when ...
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31 views

Check if object is at position, then move player as close to object without colliding, or re-direct player?

Basically what the title says, I'm using the mouse position to move the player around the screen, and the issue I'm having is that if there is, let's say, a boulder where I'm trying to run, how would ...
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0answers
19 views

Play soundeffect only once?

I am creating a game in XNA and when there is a collision between two objects a siren will sound. I have pixle-colliding between the objects and if several pixles collide the sound plays several times ...
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0answers
62 views

Java Collision detection

Hello have a game where you look for key cards. Which allow you to open certain doors. for example if u have a red key card you can open a red door. The problem is that when I don't have red key ...