A process of adjusting game objects position after collision.

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5
votes
3answers
767 views

When two moving objects collide, which one sends the message, and which one recieves it?

I am writing a platform game using an entity-component system. Entity-World collisions are robust and work very well, and I'm now working on collisions between entities. Just to be clear, in my code ...
0
votes
1answer
309 views

Having to check collisions twice per game tic

I have vertically moving elevators (3 solid tiles wide) and static solid tiles. Each are separate entities and therefore have their own respective collision routines (to check for, and resolve, ...
7
votes
3answers
672 views

Reusable top-down collision class

I've recently picked up monogame and am working on a simple top down game to get me started and learn the basics. I've got the movement and the rotation to follow the mouse sorted out but I'm stuck ...
6
votes
1answer
277 views

Collision Detection problems for vertically moving platforms

Background My game is a static screen (ie, no scrolling) 2d platformer and my CD routine is split into 2 - after vertical movements, (ie, gravity etc) I check for collisions, and if they are ...
0
votes
1answer
190 views

Resolving a collision between point and moving line

I am designing a 2d physics engine that uses Verlet integration for moving points (velocities mentioned below can be derived), constraints to represent moving line segments, and continuous collision ...
0
votes
1answer
836 views

gamemaker getting a ball to bounce 90 degrees off of a 45 angle

I am trying to get a circle to bounce off a 45 degree diamond shap using Gamemaker Studio. I would like the ball to bounce in straight lines so my directions would be 0, 90, 180, or 270 degrees, ...
0
votes
1answer
1k views

Separate axis theorem applied to AABB misunderstood

I'm trying to implement a collision system for a 2D platformer using the SAT algorithm. For what i need, my implementation only handles AABB's, i followed the instructions given here. It works, there ...
1
vote
1answer
2k views

How do I detect and handle collisions using a tile property with Slick2D?

I am trying to set up collision detection in Slick2D based on a tilemap. I currently have two layers on the maps I'm using, a background layer, and a collision layer. The collision layer has a tile ...
3
votes
1answer
378 views

Sensor based vs. AABB based collision

I'm trying to write a simple collision system, which will probably be primarily used for 2D platformers, and I've been planning out an AABB system for a few weeks now, which will work seamlessly with ...
3
votes
1answer
260 views

2D collision resolution: works on each axis individually, but not with both combined

My collision detection method is solid and detects box to box collision every time. Then comes the resolve part which I'm struggling with quite a bit. It works perfectly when I'm manipulating the ...
0
votes
0answers
656 views

Alternative to unity's character controller

I wonder what you guy would do for a cheap replacement of character controller in unity. I try a bunch of implementation and they don't work at all, what I'm doing wrong? I'm trying to make a game ...
0
votes
1answer
176 views

Collision Resolution: Objects “swap” places

I am working on making my own simple collision resolution class so I can learn a bit about how it works, while also improving my entity-component model framework. For those of you unfamiliar with a ...
3
votes
1answer
151 views

How do you get the collision plane when using AABBs? [duplicate]

My collision detection initially seemed to work well enough, but my answer to this question shows that I have went with SAT testing now instead. My goal was to find the plane at which to slide the ...
0
votes
1answer
171 views

Simple Bounding Box Multiple Collision problem

I'm making my first game, and in it I use a moving ball to hit static blocks (kinda like breakout). Basically, I loop through all of the static blocks on the screen each frame, update the position ...
2
votes
3answers
199 views

Determining which edge a collision occurred on in a platformer

First of all, this will be Open Source, and you will be mentioned for the help. We've been programming a Super Mario Remake for the iPhone with Cocos2d for school. It looks pretty great, and we ...
28
votes
6answers
2k 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 ...
3
votes
1answer
214 views

Is it possible to get the colliding sides using the separating axis theorem?

The title says it all, is it even possible to get the colliding sides? I'm checking for collisions between two OABBs, which works fine using SAT. Now I want to set the moving object's velocity to the ...
3
votes
2answers
278 views

When to detect and respond to collisions?

I've usually implemented collision detection like this in the past: Move entity Check if it collides with anything Resolve the collision by moving it back That's also the approach employed by most ...
1
vote
1answer
228 views

How to deal with pushing objects out of collision in a physics engine

I'm developing a 3D physics engine (I know, I should use one of the many good existing physics libraries, however my collision detection is optimised for objects with highly ordered highly complex ...
-1
votes
1answer
425 views

How was traditional 2D collision detection/resolution being done? [closed]

Just out of pure curiosity, I'm wondering how classic 2D games of the 80s/90s (The Legend of Zelda, Super Mario, Warcraft, ...) approached collision detection/resolution. For some reason I can't ...
4
votes
3answers
236 views

XNA Collision is quircky/wobbly, how to improve?

I am sorry if this was already answered but I couldn't find the answer. So I am doing a tile based platformer and when I was making collision I had quiet a struggle I looked here and googled for ...
0
votes
1answer
308 views

Differences between Overlap and Intersection testing?

I have heard of techniques such as overlap testing and intersection testing for collision detection and collision resolution. I looked up on the two techniques, but I don't see what differences they ...
-5
votes
2answers
103 views

Should I negate a variable or use absolute value? [closed]

this is how i was chaning ball postion if(...) //if ball goes to left of screen dx = -dx if(...) //if ball goes right of screen dx = -dx; i found some people using math.abs to move ball ...
4
votes
1answer
348 views

Help me please to choose proper path-finding algorithm

I am new to game development and just want to ask for advice. I need to know which path-finding algoritm will be suitable for my scenario: Units - any shape. But in most cases rectangles of ...
3
votes
1answer
209 views

How can I easily model semi-realistically human movement and collision in a 2D game?

I am writing a sports simulation game in which the simulated players will interact physically with each other (i.e. tackle, push, bump...) as well as do individual actions such as changing direction ...
1
vote
2answers
775 views

Resolving 2D Collision with Rectangles

For about a week I've been trying to grasp the basics of collision, but I've been driven to the point of wanting to just give up on everything when it comes to collision. I just don't understand it. ...
-2
votes
1answer
85 views

collision between two objects

to test collision i am using intersect function. if(this.getBounds_ball().intersects(this.getBounds_rect())) { but the problem is i dont know how to test where the ball is collision from. i was ...
0
votes
1answer
77 views

collision test between ball and rect [closed]

need help with collision between ball and rect. i dont know how to test if ball hit the rec from top, bottom, right or left. x = ball x y = ball y radius = ball width and height rx = rect x ry = rect ...
-1
votes
1answer
222 views

Pixel perfect collisions for platforms

i'm trying to do a pixel perfect collision but i don't know how to handle collisions when there is a jump . Here i have one image of a sample map: But maybe I've done a bad supposing all pixel like ...
-1
votes
2answers
245 views

Tile Based Collision Checking In Java?

I have my map stored in 2 arrays: Tiles : Tile names TileTypes : SOLID or BASIC I want to be able to walk through BASIC Tiles (Like ground tiles). But not the SOLID Tiles (Like wall tiles). I ...
4
votes
1answer
121 views

Collision Response: game character vs. density function

Introduction I am working on my own "novelty" game-engine project, where the world is represented by a continuous density function. It has only one interface, a function that returns the density at a ...
2
votes
1answer
237 views

Collision Resolution: How to avoid Interpenetration/Tunneling Caused by Prior Collision Handling? [duplicate]

My game processes world collisions followed by entity collisions. The problem here is that entities can break through walls the next frame when world checks are run again as a result of the prior ...
2
votes
1answer
250 views

Get intersected volume of two planes in 3D

I'm working on AABB - AABB collision response and I'm having trouble figuring one part out. My situation is as follows (see image). I have a player AABB (blue) and an object which collides (brown). ...
1
vote
1answer
666 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 ...
1
vote
1answer
637 views

2D tile-based collisions: using different methods by tile?

I'm trying to write a collision handling method that handles each of the 9 potentially colliding tiles (the player's and the 8 around him) differently according to a "CollisionType" value attached to ...
0
votes
1answer
280 views

Collision in PyGame for spinning rectangular object.touching circles

I'm creating a variation of Pong. One of the differences is that I use a rectangular structure as the object which is being bounced around, and I use circles as paddles. So far, all the collision ...
2
votes
1answer
579 views

How to calculate collision normal between two AxisAlignedBox's?

I'm writing a physics simulation in Ogre3D and I'm trying to figure out how to calculate the collision normal between two Ogre::AxisAlignedBox's. I am checking for collisions using the "intersects" ...
12
votes
3answers
2k views

Resolving a collision with forces

In my 2D physics engine, I can detect AABB vs AABB collisions, and resolve them by finding the shortest penetration vector and adding it to the AABB's position. Doing this "pushes" the first AABB ...
1
vote
1answer
238 views

Slide effect in voxel collisions

I'm making a voxel engine, and I'm trying to figure out the right way to make efficient collisions with a slide response (making the player slide against the wall). Currently my collisions are pretty ...
6
votes
3answers
357 views

Calculating impulse propagation through a rigid body after a collision

I'm working on a game. I need to work out what the impulse is at different points on a body as a result of a collision. For example, in the following diagram, if there is a collision that results in ...
1
vote
2answers
506 views

Find the Contact Normal of Rectangle Collision

It seems a lot of people have asked similar questions on this site, and every time it seems like a whole bunch of answers that don't work are given. Basically, I have two rectangles (AABBs) that ...
3
votes
1answer
421 views

Meaning of offset in pygame Mask.overlap methods

I have a situation in which two rectangles collide, and I have to detect how much did they collide so so I can redraw the objects in a way that they are only touching each others edges. It's a ...
1
vote
1answer
171 views

Confusing with an articles wording on Clamping a Vector2

I have been reading an article on Collision Detection and how to resolve it. http://www.wildbunny.co.uk/blog/2011/04/20/collision-detection-for-dummies/ In the section describing an AABB vs Circle, ...
0
votes
0answers
332 views

Separating axis theorem implementation flaky minimum translation vector based on triangle orientation

I've implemented some collision detection using separating axis theorem. Works fine for axis-aligned rectangles and two out of four possible right triangle orientations. For some reason when the ...
4
votes
2answers
804 views

XNA 4.0 / C# Collision Response

Okay, this is really starting to annoy me. First of all, detecting collisions is nice and easy. I have a list of tiles, and a player. The player and each tile have their own rectangles. (The tiles ...
0
votes
2answers
166 views

Why does this collision detection & resolution code only work for one side?

I am having a bit of trouble with my collision detection. It only works correctly for the right side, meaning, if I enter the tile from any other side, it brings me to the right side. Here is my ...
4
votes
1answer
297 views

How to handle collision resolution in a top-down car game?

I have a top-down car game which takes place in an arena. The game is very very light on physics, so I'm not actually using a physics engine. The cars' movement is mostly managed by a struct I called ...
4
votes
2answers
167 views

Why is my collision resolution failing on the corners?

I'm tearing my hair out trying to work out how to handle my collision resolution at the corners of the rectangles that I'm colliding with. The code that I'm working with is: class Player(object): ...
-1
votes
2answers
260 views

My 2D collision code does not work as expected. How do I fix it?

I have a simple 2D game with a tile-based map. I am new to game development, I followed the LazyFoo tutorials on SDL. The tiles are in a bmp file, but each tile inside it corresponds to an internal ...
0
votes
0answers
165 views

Simulating smooth movement along a line after calculating a collision containing a restitution of zero in 2D

[for tl;dr see after listing] //...Code to determine shapes types involved in collision here... //...Rectangle-Line collision detected. ...