Search Results

Search found 10978 results on 440 pages for 'collision testing'.

Page 3/440 | < Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >

• Collision Resolution

  - by ultifinitus

  Hey all, I'm making a simple side-scrolling game, and I would appreciate some input! My collision detection system is a simple bounding box detection, so it's really easy to implement. However my collision resolution is ridiculous! Currently I have a little formula like this: if (colliding(firstObject,secondObject)) firstObject.resolve_collision(yAxisOffset); if (colliding(firstObject,secondObject)) firstObject.resolve_collision(xAxisOffset); where yAxisOffset is only set if the first object's previous y position was outside the second object's collision frame, respectively xAxisOffset as well. Now this is working great, in general. However there is a single problem. When I have a stack of objects and I push the first object against that stack, the first object get's "stuck," on the stack. What's I think is happening is the object's collision system checks and resolves for collisions based on creation time, so If I check one axis, then the other, the object will "sink" object directly along the checking axis. This sinking action causes the collision detection routine to think there's a gap between our position and the other object's position, and when I finally check the object that I've already sunk into, my object's position is resolved to it's original position... All this is great, and I'm sure if I bang my head against a wall long enough i'll come up with a working algorithm, but I'd rather not =). So what in the heck do you think I should do? How could I change my collision resolution system to fix this? Here's the program (temporary link, not sure how long it'll last) (notes: arrow keys to navigate, click to drop block, x to jump) I'd appreciate any help you can offer!

  Read the article

• Faster 2D Collision detection

  - by eShredder

  Recently I've been working on a fast-paced 2d shooter and I came across a mighty problem. Collision detection. Sure, it is working, but it is very slow. My goal is: Have lots of enemies on screen and have them to not touch each other. All of the enemies are chasing the player entity. Most of them have the same speed so sooner or later they all end up taking the same space while chasing the player. This really drops the fun factor since, for the player, it looks like you are being chased by one enemy only. To prevent them to take the same space I added a collision detection (a very basic 2D detection, the only method I know of) which is. Enemy class update method Loop through all enemies (continue; if the loop points at this object) If enemy object intersects with this object Push enemy object away from this enemy object This works fine. As long as I only have <200 enemy entities that is. When I get closer to 300-350 enemy entities my frame rate begins to drop heavily. First I thought it was bad rendering so I removed their draw call. This did not help at all so of course I realised it was the update method. The only heavy part in their update method is this each-enemy-loops-through-every-enemy part. When I get closer to 300 enemies the game does a 90000 (300x300) step itteration. My my~ I'm sure there must be another way to aproach this collision detection. Though I have no idea how. The pages I find is about how to actually do the collision between two objects or how to check collision between an object and a tile. I already know those two things. tl;dr? How do I aproach collision detection between LOTS of entities? Quick edit: If it is to any help, I'm using C# XNA.

  Read the article

• What are the disadvantages of automated testing?

  - by jkohlhepp

  There are a number of questions on this site that give plenty of information about the benefits that can be gained from automated testing. But I didn't see anything that represented the other side of the coin: what are the disadvantages? Everything in life is a tradeoff and there are no silver bullets, so surely there must be some valid reasons not to do automated testing. What are they? Here's a few that I've come up with: Requires more initial developer time for a given feature Requires a higher skill level of team members Increase tooling needs (test runners, frameworks, etc.) Complex analysis required when a failed test in encountered - is this test obsolete due to my change or is it telling me I made a mistake? Edit I should say that I am a huge proponent of automated testing, and I'm not looking to be convinced to do it. I'm looking to understand what the disadvantages are so when I go to my company to make a case for it I don't look like I'm throwing around the next imaginary silver bullet. Also, I'm explicity not looking for someone to dispute my examples above. I am taking as true that there must be some disadvantages (everything has trade-offs) and I want to understand what those are.

  Read the article

• Should programmers itemize testing for projects? [on hold]

  - by Patton77

  I recently hired a programming team to do a port of my iPad app to the iPhone and Android platforms. Now, in a separate contract, I am asking them to implement a bunch of tips on how to play the app, similar like you would find in Candy Crush or Cut the Rope. They want to charge 12 hours @ $35/hr for the "Testing all of the Tips", telling me that normally it would take them more than 25 hours but that they will 'bear the difference'. I am not familiar with this level of itemization, but maybe it's a new practice? I am used to devs doing their own quality control, and then having a testing/acceptance period. They are using Cocos 2D-X, and they say that the tips going to multiple platforms makes all of the hours jack up. I feel like they might be overcharging, and it's difficult for me to know because it's kind of like with a mechanic. "It took us 5 hours to replace the radiator". How can you dispute that? It seems to me that most of you would charge for the work but NOT for hours that you are 'testing'. Am I missing something? Thanks for any help and advice you can give!

  Read the article

• Having to check collisions twice per game tic

  - by user22241

  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, collisions with the main character) I check my vertical collisions after characters vertical movements and then horizontal collisions after horizontal movements. The problem is that I want my platform to kill the player if it squashes him from the top, and also if he's on a moving platform (that is moving up) that squashes him into a solid block. Correct behaviour, player on solid blocks being squashed from above by decending elevator Here is what happens. Gravity pushes character into solid block, solid block collision routine corrects characters position and sits him on the solid block which pushes him into the moving elevator, elevator routine then checks for collision and kills player. This assumes I am checking solid blocks first, then elevator collisions. However, if it's the other way around, this happens.... Incorrect behaviour, player on accending elevator gets pushed into solid blocks above Player is on an elevator moving up, gravity pushes him into the elevator, solid block CD routine detects no collision, no action taken. Elevator CD routine detects character has been pushed into elevator by gravity, corrects this by moving character up and sitting him on the elevator and pushes him into the solid blocks above, however the solid block vertical routine has now already run for this tic, so the game continues and the next solid block collision that is encountered is the horizontal routine. This detects a collision and moves the character out of the collision to the left or right of the block which looks odd to say the least (character should get killed here). The only way I've managed to get this working correctly is by running the solid block CD, then the elevator CD, then the solid block CD again straight after. This is clearly wasteful but I can't figure out how else to do this. Any help would be appreciated.

  Read the article

• Java collision detection and player movement: tips

  - by Loris

  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 from the guide (should i link this guide?). I'm just trying to expand and complete it. This is the class that take care of updates movements and firing mechanism (and collision detection): public class ArenaController { private Arena arena; /** selected cell for movement */ private float targetX, targetY; /** true if droid is moving */ private boolean moving = false; /** true if droid is shooting to enemy */ private boolean shooting = false; private DroidController droidController; public ArenaController(Arena arena) { this.arena = arena; this.droidController = new DroidController(arena); } public void update(float delta) { Droid droid = arena.getDroid(); //droid movements if (moving) { droidController.moveDroid(delta, targetX, targetY); //check if arrived if (droid.getX() == targetX && droid.getY() == targetY) moving = false; } //firing mechanism if(shooting) { //stop shot if there aren't bullets if(arena.getBullets().isEmpty()) { shooting = false; } for(int i = 0; i < arena.getBullets().size(); i++) { //current bullet Bullet bullet = arena.getBullets().get(i); System.out.println(bullet.getBounds()); //angle calculation double angle = Math.atan2(bullet.getEnemyY() - bullet.getY(), bullet.getEnemyX() - bullet.getX()); //increments x and y bullet.setX((float) (bullet.getX() + (Math.cos(angle) * bullet.getSpeed() * delta))); bullet.setY((float) (bullet.getY() + (Math.sin(angle) * bullet.getSpeed() * delta))); //collision with obstacles for(int j = 0; j < arena.getObstacles().size(); j++) { Obstacle obs = arena.getObstacles().get(j); if(bullet.getBounds().intersects(obs.getBounds())) { System.out.println("Collision detect!"); arena.removeBullet(bullet); } } //collisions with enemies for(int j = 0; j < arena.getEnemies().size(); j++) { Enemy ene = arena.getEnemies().get(j); if(bullet.getBounds().intersects(ene.getBounds())) { System.out.println("Collision detect!"); arena.removeBullet(bullet); } } } } } public boolean onClick(int x, int y) { //click on empty cell if(arena.getGrid()[(int)(y / Arena.TILE)][(int)(x / Arena.TILE)] == null) { //coordinates targetX = x / Arena.TILE; targetY = y / Arena.TILE; //enables movement moving = true; return true; } //click on enemy: fire if(arena.getGrid()[(int)(y / Arena.TILE)][(int)(x / Arena.TILE)] instanceof Enemy) { //coordinates float enemyX = x / Arena.TILE; float enemyY = y / Arena.TILE; //new bullet Bullet bullet = new Bullet(); //start coordinates bullet.setX(arena.getDroid().getX()); bullet.setY(arena.getDroid().getY()); //end coordinates (enemie) bullet.setEnemyX(enemyX); bullet.setEnemyY(enemyY); //adds bullet to arena arena.addBullet(bullet); //enables shooting shooting = true; return true; } return false; } As you can see for collision detection i'm trying to use Rectangle object. Droid example: import java.awt.geom.Rectangle2D; public class Droid { private float x; private float y; private float speed = 20f; private float rotation = 0f; private float damage = 2f; public static final int DIAMETER = 32; private Rectangle2D rectangle; public Droid() { rectangle = new Rectangle2D.Float(x, y, DIAMETER, DIAMETER); } public float getX() { return x; } public void setX(float x) { this.x = x; //rectangle update rectangle.setRect(x, y, DIAMETER, DIAMETER); } public float getY() { return y; } public void setY(float y) { this.y = y; //rectangle update rectangle.setRect(x, y, DIAMETER, DIAMETER); } public float getSpeed() { return speed; } public void setSpeed(float speed) { this.speed = speed; } public float getRotation() { return rotation; } public void setRotation(float rotation) { this.rotation = rotation; } public float getDamage() { return damage; } public void setDamage(float damage) { this.damage = damage; } public Rectangle2D getRectangle() { return rectangle; } } For now, if i start the application and i try to shot to an enemy, is immediately detected a collision and the bullet is removed! Can you help me with this? If the bullet hit an enemy or an obstacle in his way, it must disappear. Ps: i know that the movements of the bullets should be managed in another class. This code is temporary. update I realized what happens, but not why. With those for loops (which checks collisions) the movements of the bullets are instantaneous instead of gradual. In addition to this, if i add the collision detection to the Droid, the method intersects returns true ALWAYS while the droid is moving! public void moveDroid(float delta, float x, float y) { Droid droid = arena.getDroid(); int bearing = 1; if (droid.getX() > x) { bearing = -1; } if (droid.getX() != x) { droid.setX(droid.getX() + bearing * droid.getSpeed() * delta); //obstacles collision detection for(Obstacle obs : arena.getObstacles()) { if(obs.getRectangle().intersects(droid.getRectangle())) { System.out.println("Collision detected"); //ALWAYS HERE } } //controlla se è arrivato if ((droid.getX() < x && bearing == -1) || (droid.getX() > x && bearing == 1)) droid.setX(x); } bearing = 1; if (droid.getY() > y) { bearing = -1; } if (droid.getY() != y) { droid.setY(droid.getY() + bearing * droid.getSpeed() * delta); if ((droid.getY() < y && bearing == -1) || (droid.getY() > y && bearing == 1)) droid.setY(y); } }

  Read the article

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

  - by farmdve

  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 number of the type of tile(color, or wall). The game is simple, but the code is a lot so I can only post snippets. // Player moved out of the map if((player.box.x < 0)) player.box.x += GetVelocity(player, 0); if((player.box.y < 0)) player.box.y += GetVelocity(player, 1); if((player.box.x > (LEVEL_WIDTH - DOT_WIDTH))) player.box.x -= GetVelocity(player, 0); if((player.box.y > (LEVEL_HEIGHT - DOT_HEIGHT))) player.box.y -= GetVelocity(player, 1); // Now that we are here, we check for collisions if(touches_wall(player.box)) { if(player.box.x < player.prev_x) { player.box.x += GetVelocity(player, 0); } if(player.box.x > player.prev_x) { player.box.x -= GetVelocity(player, 0); } if(player.box.y < player.prev_y) { player.box.y += GetVelocity(player, 1); } if(player.box.y > player.prev_y) { player.box.y -= GetVelocity(player, 1); } } player.prev_x = player.box.x; player.prev_y = player.box.y; Let me explain, player is a structure with the following contents typedef struct { Rectangle box; //Player position on a map(tile or whatever). int prev_x, prev_y; // Previous positions int key_press[3]; // Stores which key was pressed/released. Limited to three keys. E.g Left,right and perhaps jump if possible in 2D int velX, velY; // Velocity for X and Y coordinate. //Health int health; bool main_character; uint32_t jump_ticks; } Player; And Rectangle is just a typedef of SDL_Rect. GetVelocity is a function that according to the second argument, returns the velocity for the X or Y axis. This code I have basically works, however inside the if(touches_wall(player.box)) if statement, I have 4 more. These 4 if statements are responsible for detecting collision on all 4 sides(up,down,left,right). However, they also act as a block for any other movement. Example: I move down the object and collide with the wall, as I continue to move down and still collide with the wall, I wish to move left or right, which is indeed possible(not to mention in 3D games), but remember the 4 if statements? They are preventing me from moving anywhere. The original code on the LazyFoo Productions website has no problems, but it was written in C++, so I had to rewrite most of it to work, which is probably where the problem comes from. I also use a different method of moving, than the one in the examples. Of course, that was just an example. I wish to be able to move no matter at which wall I collide. Before this bit of code, I had another one that had more logic in there, but it was flawed.

  Read the article

• Unit testing in Django

  - by acjohnson55

  I'm really struggling to write effective unit tests for a large Django project. I have reasonably good test coverage, but I've come to realize that the tests I've been writing are definitely integration/acceptance tests, not unit tests at all, and I have critical portions of my application that are not being tested effectively. I want to fix this ASAP. Here's my problem. My schema is deeply relational, and heavily time-oriented, giving my model object high internal coupling and lots of state. Many of my model methods query based on time intervals, and I've got a lot of auto_now_add going on in timestamped fields. So take a method that looks like this for example: def summary(self, startTime=None, endTime=None): # ... logic to assign a proper start and end time # if none was provided, probably using datetime.now() objects = self.related_model_set.manager_method.filter(...) return sum(object.key_method(startTime, endTime) for object in objects) How does one approach testing something like this? Here's where I am so far. It occurs to me that the unit testing objective should be given some mocked behavior by key_method on its arguments, is summary correctly filtering/aggregating to produce a correct result? Mocking datetime.now() is straightforward enough, but how can I mock out the rest of the behavior? I could use fixtures, but I've heard pros and cons of using fixtures for building my data (poor maintainability being a con that hits home for me). I could also setup my data through the ORM, but that can be limiting, because then I have to create related objects as well. And the ORM doesn't let you mess with auto_now_add fields manually. Mocking the ORM is another option, but not only is it tricky to mock deeply nested ORM methods, but the logic in the ORM code gets mocked out of the test, and mocking seems to make the test really dependent on the internals and dependencies of the function-under-test. The toughest nuts to crack seem to be the functions like this, that sit on a few layers of models and lower-level functions and are very dependent on the time, even though these functions may not be super complicated. My overall problem is that no matter how I seem to slice it, my tests are looking way more complex than the functions they are testing.

  Read the article

• design pattern for unit testing? [duplicate]

  - by Maddy.Shik

  This question already has an answer here: Unit testing best practices for a unit testing newbie 4 answers I am beginner in developing test cases, and want to follow good patterns for developing test cases rather than following some person or company's specific ideas. Some people don't make test cases and just develop the way their senior have done in their projects. I am facing lot problems like object dependencies (when want to test method which persist A object i have to first persist B object since A is child of B). Please suggest some good books or sites preferably for learning design pattern for unit test cases. Or reference to some good source code or some discussion for Dos and Donts will do wonder. So that i can avoid doing mistakes be learning from experience of others.

  Read the article

• Collision library for bullet hell in Python

  - by darkfeline

  I am making a bullet hell game in Python and am looking for a suitable collision library, taking the following into consideration: The library should do 2D polygon collision. It should be very fast. As a bullet hell game, I expect to do collision checks between hundreds, likely thousands of objects every frame at a consistent 60fps. Good documentation Permissive license (like MIT, not GPL) I am also considering writing my own library in C/C++ and wrapping with python ctypes in the event that no such library exists, though I do not have experience with collision detection algorithms, so I am not sure if this would be more trouble than it's worth. Could someone provide some guidance on this matter?

  Read the article

• How can I improve this collision detection logic?

  - by Dan

  I’m trying to make an android game and I’m having a bit of trouble getting the collision detection to work. It works sometimes but my conditions aren’t specific enough and my program gets it wrong. How could I improve the following if conditions? public boolean checkColisionWithPlayer( Player player ) { // Top Left // Top Right // Bottom Right // Bottom Left // int[][] PP = { { player.x, player.y }, { player.x + player.width, player.y }, {player.x + player.height, player.y + player.width }, { player.x, player.y + player.height } }; // TOP LEFT - PLAYER // if( ( PP[0][0] > x && PP[0][0] < x + width ) && ( PP[0][1] > y && PP[0][1] < y + height ) && ( (x - player.x) < 0 ) ) { player.isColided = true; //player.isSpinning = false; // Collision On Right if( PP[0][0] > ( x + width/2 ) && ( PP[0][1] - y < ( x + width ) - PP[0][0] ) ) { Log.i("Colision", "Top Left - Right Side"); player.x = ( x + width ) + 1; player.Vh = player.phy.getVelsoityWallColision(player.Vh, player.Cr); } // Collision On Bottom else if( PP[0][1] > ( y + height/2 ) ) { Log.i("Colision", "Top Left - Bottom Side"); player.y = ( y + height ) + 1; if( player.Vv > 0 ) player.Vv = 0; } return true; } // TOP RIGHT - PLAYER // else if( ( PP[1][0] > x && PP[1][0] < x + width ) && ( PP[1][1] > y && PP[1][1] < y + height ) && ( (x - player.x) > 0 ) ) { player.isColided = true; //player.isSpinning = false; // Collision On Left if( PP[1][0] < ( x + width/2 ) && ( PP[1][0] - x < PP[1][1] - y ) ) { Log.i("Colision", "Top Right - Left Side"); player.x = ( x ) + 1; player.Vh = player.phy.getVelsoityWallColision(player.Vh, player.Cr); } // Collision On Bottom else if( PP[1][1] > ( y + height/2 ) ) { Log.i("Colision", "Top Right - Bottom Side"); player.y = ( y + height ) + 1; if( player.Vv > 0 ) player.Vv = 0; } return true; } // BOTTOM RIGHT - PLAYER // else if( ( PP[2][0] > x && PP[2][0] < x + width ) && ( PP[2][1] > y && PP[2][1] < y + height ) ) { player.isColided = true; //player.isSpinning = false; // Collision On Left if( PP[2][0] < ( x + width/2 ) && ( PP[2][0] - x < PP[2][1] - y ) ) { Log.i("Colision", "Bottom Right - Left Side"); player.x = ( x ) + 1; player.Vh = player.phy.getVelsoityWallColision(player.Vh, player.Cr); } // Collision On Top else if( PP[2][1] < ( y + height/2 ) ) { Log.i("Colision", "Bottom Right - Top Side"); player.y = y - player.height; player.Vv = player.phy.getVelsoityWallColision(player.Vv, player.Cr); //player.Vh = -1 * ( player.phy.getVelsoityWallColision(player.Vv, player.Cr) ); int rs = x - player.x; Log.i("RS", String.format("%d", rs)); if( rs > 0 ) { player.direction = -1; player.isSpinning = true; player.Vh = -0.5 * ( player.phy.getVelsoityWallColision(player.Vv, player.Cr) ); } if( rs < 0 ) { player.direction = 1; player.isSpinning = true; player.Vh = 0.5 * ( player.phy.getVelsoityWallColision(player.Vv, player.Cr) ); } player.rotateSpeed = 1 * rs; } return true; } // BOTTOM LEFT - PLAYER // else if( ( PP[3][0] > x && PP[3][0] < x + width ) && ( PP[3][1] > y && PP[3][1] < y + height ) )//&& ( (x - player.x) > 0 ) ) { player.isColided = true; //player.isSpinning = false; // Collision On Right if( PP[3][0] > ( x + width/2 ) && ( PP[3][1] - y < ( x + width ) - PP[3][0] ) ) { Log.i("Colision", "Bottom Left - Right Side"); player.x = ( x + width ) + 1; player.Vh = player.phy.getVelsoityWallColision(player.Vh, player.Cr); } // Collision On Top else if( PP[3][1] < ( y + height/2 ) ) { Log.i("Colision", "Bottom Left - Top Side"); player.y = y - player.height; player.Vv = player.phy.getVelsoityWallColision(player.Vv, player.Cr); //player.Vh = -1 * ( player.phy.getVelsoityWallColision(player.Vv, player.Cr) ); int rs = x - player.x; //Log.i("RS", String.format("%d", rs)); //player.direction = -1; //player.isSpinning = true; if( rs > 0 ) { player.direction = -1; player.isSpinning = true; player.Vh = -1 * ( player.phy.getVelsoityWallColision(player.Vv, player.Cr) ); } if( rs < 0 ) { player.direction = 1; player.isSpinning = true; player.Vh = 1 * ( player.phy.getVelsoityWallColision(player.Vv, player.Cr) ); } player.rotateSpeed = 1 * rs; } //try { Thread.sleep(1000, 0); } //catch (InterruptedException e) {} return true; } else { player.isColided = false; player.isSpinning = true; } return false; }

  Read the article

• checking for collision detection

  - by bill

  I am trying to create a game where you have a player and you can move right,left, and jump. kind of like mario but its not a side scroller. also i want to use 2d array to make a tile map. my big problem is that i dont understand how to check for collision. i spend about 2 week thinking about this and i came up with 2 solution but they both have problems. let say my map is: 0 = sky 1 = player 2 = ground 00000 10002 22022 Solution 1: move the '1'(player) and update the map less say player wants to move right, then x+=grid[x+1][y] this make the collision easy bc you can just check if if(grid[x][y+1] == 2){ //player is standing on top of ground } problem with this when u hit right key player will move (x*Titlewidth) to right. and as you can see the animation wont look smooth. Solution 2: move player and dont update map player_x += 2 this will make the animation more smoother bc i am just moving 2 pixels. problem1: i cant update map bc if player some times will be middle of int(2d array). but thats ok sinces its not a side scroller so updating the map is not a big deal. problem2: only way to check for collision is to use java intersection method. but then player have to be atleast 1 or 2 pixel in ground in order to check for collision. and as you can see that wont look good too. plz note this is my first collision game in java. so plz try to explain alot otherwise i wont understand it.

  Read the article

• Pixel Collision - Detecting corners

  - by Milkboat

  How would I go about detecting the corners of a texture when I use pixel collision detection? I read about corner collision with rectangles, but I am unsure how to adapt it to my situation. Right now my map is tile based and I do rectangular collision until the player is intersecting with a blocked tile, then I switch to pixel collision. The effect I would like to achieve is when the player hits the corner of an object to push him around the side so he doesn't just hit the edge and stop. Any ideas?

  Read the article

• 2D Rectangle Collision Response with Multiple Rectangles

  - by Justin Skiles

  Similar to: Collision rectangle response I have a level made up of tiles where the edges of the level are made up of collidable rectangles. The player's collision box is represented by a rectangle as well. The player can move in 8 directions. The player's velocity is equal in X and Y directions and constant. Each update, I am checking the player's collision against all tiles that are a certain distance away. When the player collides with a rectangle, I am finding the intersection depth and resolving along the most shallow axis followed by the other axis. This resolution happens for both axes simultaneously. See below for two examples of situations where I am having trouble. Moving up-left against the left wall In the scenario below, the player is colliding with two tiles. The tile intersection depth is equal on both axes for the top tile and more shallow in the X axis for the middle tile. Because the player is moving up the wall, the player should slide in an upward direction along the wall. This works properly as long as the rectangle with the more shallow depth is evaluated first. If the equal intersection depth rectangle is evaluated first, there is a chance the player becomes stuck. Moving up-left against the top wall Here is an identical scenario with the exception that the collision is with the top wall. The same problem occurs at the corners when intersection depth is equal for both axes. I guess my overall question is: How can I ensure that collision response occurs on tiles that have non-equal intersection depth before tiles that have equal intersection depth in order to get around the weirdness that occurs at these corners. Sean's answer in the linked question was good, but his solution required having different velocity components in a certain direction. My situation has equal velocities, so there's no good way to tell which direction to resolve at corners. I hope I have made my explanation clear.

  Read the article

• Collision within a poly

  - by G1i1ch

  For an html5 engine I'm making, for speed I'm using a path poly. I'm having trouble trying to find ways to get collision with the walls of the poly. To make it simple I just have a vector for the object and an array of vectors for the poly. I'm using Cartesian vectors and they're 2d. Say poly = [[550,0],[169,523],[-444,323],[-444,-323],[169,-523]], it's just a pentagon I generated. The object that will collide is object, object.pos is it's position and object.vel is it's velocity. They're both 2d vectors too. I've had some success to get it to find a collision, but it's just black box code I ripped from a c++ example. It's very obscure inside and all it does though is return true/false and doesn't return what vertices are collided or collision point, I'd really like to be able to understand this and make my own so I can have more meaningful collision. I'll tackle that later though. Again the question is just how does one find a collision to walls of a poly given you know the poly vertices and the object's position + velocity? If more info is needed please let me know. And if all anyone can do is point me to the right direction that's great.

  Read the article

• Circle-Line Collision Detection Problem

  - by jazzdawg

  I am currently developing a breakout clone and I have hit a roadblock in getting collision detection between a ball (circle) and a brick (convex polygon) working correctly. I am using a Circle-Line collision detection test where each line represents and edge on the convex polygon brick. For the majority of the time the Circle-Line test works properly and the points of collision are resolved correctly. Collision detection working correctly. However, occasionally my collision detection code returns false due to a negative discriminant when the ball is actually intersecting the brick. Collision detection failing. I am aware of the inefficiency with this method and I am using axis aligned bounding boxes to cut down on the number of bricks tested. My main concern is if there are any mathematical bugs in my code below. /* * from and to are points at the start and end of the convex polygons edge. * This function is called for every edge in the convex polygon until a * collision is detected. */ bool circleLineCollision(Vec2f from, Vec2f to) { Vec2f lFrom, lTo, lLine; Vec2f line, normal; Vec2f intersectPt1, intersectPt2; float a, b, c, disc, sqrt_disc, u, v, nn, vn; bool one = false, two = false; // set line vectors lFrom = from - ball.circle.centre; // localised lTo = to - ball.circle.centre; // localised lLine = lFrom - lTo; // localised line = from - to; // calculate a, b & c values a = lLine.dot(lLine); b = 2 * (lLine.dot(lFrom)); c = (lFrom.dot(lFrom)) - (ball.circle.radius * ball.circle.radius); // discriminant disc = (b * b) - (4 * a * c); if (disc < 0.0f) { // no intersections return false; } else if (disc == 0.0f) { // one intersection u = -b / (2 * a); intersectPt1 = from + (lLine.scale(u)); one = pointOnLine(intersectPt1, from, to); if (!one) return false; return true; } else { // two intersections sqrt_disc = sqrt(disc); u = (-b + sqrt_disc) / (2 * a); v = (-b - sqrt_disc) / (2 * a); intersectPt1 = from + (lLine.scale(u)); intersectPt2 = from + (lLine.scale(v)); one = pointOnLine(intersectPt1, from, to); two = pointOnLine(intersectPt2, from, to); if (!one && !two) return false; return true; } } bool pointOnLine(Vec2f p, Vec2f from, Vec2f to) { if (p.x >= min(from.x, to.x) && p.x <= max(from.x, to.x) && p.y >= min(from.y, to.y) && p.y <= max(from.y, to.y)) return true; return false; }

  Read the article

• Moving objects colliding when using unalligned collision avoidance (steering)

  - by James Bedford

  I'm having trouble with unaligned collision avoidance for what I think is a rare case. I have set two objects to move towards each other but with a slight offset, so one of the objects is moving slightly upwards, and one of the objects is moving slightly downwards. In my unaligned collision avoidance steering algorithm I'm finding the points on the object's forward line and the other object's forward line where these two lines are the closest. If these closest points are within a collision avoidance distance, and if the distance between them is smaller than the two radii of the two object's bounding spheres, then the objects should steer away in the appropriate direction. The problem is that for my case, the closest points on the lines are calculated to be really far away from the actual collision point. This is because the two forward lines for each object are moving away from each other as the objects pass. The problem is that because of this, no steering takes place, and the two objects partially collide. Does anyone have any suggestions as to how I can correctly calculate the point of collision? Perhaps by somehow taking into account the size of the two objects?

  Read the article

• Changing direction after collision

  - by Balint

  In the first tutorial for GameMaker (catch the clown), I want to set the direction of the clown after the collision with the wall. I want to do it by pressing the wall object with the mouse (before the collision, to set the angle parameter). For example by pressing only once the wall object it would change the clown's direction after collision by 45 degrees, twice by 90 degrees, and so on. How can I do that?

  Read the article

• Fixing a collision detection bug in Slick2D

  - by Jesse Prescott

  My game has a bug with collision detection. If you go against the wall and tap forward/back sometimes the game thinks the speed you travelled at is 0 and the game doesn't know how to get you out of the wall. My collision detection works by getting the speed you hit the wall at and if it is positive it moves you back, if it is negative it moves you forward. It might help if you download it: https://rapidshare.com/files/1550046269/game.zip Sorry if I explained badly, it's hard to explain. float maxSpeed = 0.3f; float minSpeed = -0.2f; float acceleration = 0.002f; float deacceleration = 0.001f; float slowdownSpeed = 0.002f; float rotateSpeed = 0.08f; static float currentSpeed = 0; boolean up = false; boolean down = false; boolean noKey = false; static float rotate = 0; //Image effect system static String locationCarNormal; static String locationCarFront; static String locationCarBack; static String locationCarBoth; static boolean carFront = false; static boolean carBack = false; static String imageRef; boolean collision = false; public ComponentPlayerMovement(String id, String ScarNormal, String ScarFront, String ScarBack, String ScarBoth) { this.id = id; playerBody = new Rectangle(900/2-16, 700/2-16, 32, 32); locationCarNormal = ScarNormal; locationCarFront = ScarFront; locationCarBack = ScarBack; locationCarBoth = ScarBoth; imageRef = locationCarNormal; } @Override public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException { Input input = gc.getInput(); playerBody.transform(Transform.createRotateTransform(2)); float hip = currentSpeed * delta; float unstuckspeed = 0.05f * delta; if(carBack && !carFront) { imageRef = locationCarBack; ComponentImageRender.updateImage(); } else if(carFront && !carBack) { imageRef = locationCarFront; ComponentImageRender.updateImage(); } else if(carFront && carBack) { imageRef = locationCarBoth; ComponentImageRender.updateImage(); } if(input.isKeyDown(Input.KEY_RIGHT)) { rotate += rotateSpeed * delta; owner.setRotation(rotate); } if(input.isKeyDown(Input.KEY_LEFT)) { rotate -= rotateSpeed * delta; owner.setRotation(rotate); } if(input.isKeyDown(Input.KEY_UP)) { if(!collision) { up = true; noKey = false; if(currentSpeed < maxSpeed) { currentSpeed += acceleration; } MapCoordStorage.mapX += hip * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= hip * Math.cos(Math.toRadians(rotate)); } else { currentSpeed = 1; } } else if(input.isKeyDown(Input.KEY_DOWN) && !collision) { down = true; noKey = false; if(currentSpeed > minSpeed) { currentSpeed -= slowdownSpeed; } MapCoordStorage.mapX += hip * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= hip * Math.cos(Math.toRadians(rotate)); } else { noKey = true; if(currentSpeed > 0) { currentSpeed -= deacceleration; } else if(currentSpeed < 0) { currentSpeed += acceleration; } MapCoordStorage.mapX += hip * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= hip * Math.cos(Math.toRadians(rotate)); } if(entityCollisionWith()) { collision = true; if(currentSpeed > 0 || up) { up = true; currentSpeed = 0; carFront = true; MapCoordStorage.mapX += unstuckspeed * Math.sin(Math.toRadians(rotate-180)); MapCoordStorage.mapY -= unstuckspeed * Math.cos(Math.toRadians(rotate-180)); } else if(currentSpeed < 0 || down) { down = true; currentSpeed = 0; carBack = true; MapCoordStorage.mapX += unstuckspeed * Math.sin(Math.toRadians(rotate)); MapCoordStorage.mapY -= unstuckspeed * Math.cos(Math.toRadians(rotate)); } else { currentSpeed = 0; } } else { collision = false; up = false; down = false; } if(currentSpeed >= -0.01f && currentSpeed <= 0.01f && noKey && !collision) { currentSpeed = 0; } } public static boolean entityCollisionWith() throws SlickException { for (int i = 0; i < BlockMap.entities.size(); i++) { Block entity1 = (Block) BlockMap.entities.get(i); if (playerBody.intersects(entity1.poly)) { return true; } } return false; } }

  Read the article

• Collision Systems Implementation

  - by hrr4

  Just curious what might be a good way to implement a decent collision system. As a class inherited by a base Entity class? Currently I'm stuck and could just use a couple better ideas than my own. Any help is appreciated! Edit: Sorry, it's 2D Collisioning but honestly, I'm not looking for specific collision methods. I'm looking more about the lines of implementation. Just curious of some of the common methods of how to implement collision systems such as: Should the entire collision system be it's own class? What, if anything, should be inheritable? These are some of my questions. Sorry for the confusion.

  Read the article

• 2D Tile Collision free movement

  - by andrepcg

  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 empty or not. Besides having a grid for collision, there's still free movement inside a tile. For each entity, in the end of the update function I simply increase the position by the velocity: pos.x += v.x; pos.y += v.y; I already have a collision grid created but my collide function is not great, i'm not sure how to handle it. I can check if the collision occurs but the way I handle is terrible. int leftTile = repelBox.x / grid->cellSize; int topTile = repelBox.y / grid->cellSize; int rightTile = (repelBox.x + repelBox.w) / grid->cellSize; int bottomTile = (repelBox.y + repelBox.h) / grid->cellSize; for (int y = topTile; y <= bottomTile; ++y) { for (int x = leftTile; x <= rightTile; ++x) { if (grid->getCell(x, y) == BLOCKED){ Rect colBox = grid->getCellRectXY(x, y); Rect xAxis = Rect(pos.x - 20 / 2.0f, pos.y - 20 / 4.0f, 20, 10); Rect yAxis = Rect(pos.x - 20 / 4.0f, pos.y - 20 / 2.0f, 10, 20); if (colBox.Intersects(xAxis)) v.x *= -1; if (colBox.Intersects(yAxis)) v.y *= -1; } } } If instead of reversing the direction I set it to false then when the entity tries to get away from the wall it's still intersecting the tile and gets stuck on that position. EDIT: I've worked with Flashpunk and it has a great function for movement and collision called moveBy. Are there any simplified implementations out there so I can check them out?

  Read the article

• Fast, accurate 2d collision

  - by Neophyte

  I'm working on a 2d topdown shooter, and now need to go beyond my basic rectangle bounding box collision system. I have large levels with many different sprites, all of which are different shapes and sizes. The textures for the sprites are all square png files with transparent backgrounds, so I also need a way to only have a collision when the player walks into the coloured part of the texture, and not the transparent background. I plan to handle collision as follows: Check if any sprites are in range of the player Do a rect bounding box collision test Do an accurate collision (Where I need help) I don't mind advanced techniques, as I want to get this right with all my requirements in mind, but I'm not sure how to approach this. What techniques or even libraries to try. I know that I will probably need to create and store some kind of shape that accurately represents each sprite minus the transparent background. I've read that per pixel is slow, so given my large levels and number of objects I don't think that would be suitable. I've also looked at Box2d, but haven't been able to find much documentation, or any examples of how to get it up and running with SFML.

  Read the article

• Help with collision detection method [on hold]

  - by derek jones

  I was wondering if any of you could spare me some time to go over some collision detection on my platform engine. i tried XNA a few years back but for reasons i wont go into online could not continue, my health is now at a state where i am ready to try again but due to my current circumstances (and age) schooling is out of the question so i turn to you guys for help. Whilst i can adapt the MS sample ok and have some great features, you will agree modifying code is not really learning. So i have spent the last couple of week going over my old MS code and lots of stuff online and decided on what i want and have ported most of it over to code that i understand 90% of. I have my player class that moves about, jumps with gravity, has animations and a bounding box that follows it around. I have my map & basic level class to load levels from text files. Its just how i handle the collisions that i am struggling with as i will want per pixel collision on some tiles(i have code for this in a pong game i made so that should be ok). I'm pretty clear in my mind on what i need to do its just putting it in code and in the right place, here's what i was thinking. I was going to do it all in layers, have a tile layer, a collision layer & an item layer this way i could make a nice map editor in Win Forms at some point. Anyway i need to read in the collision layer the assign each tile a rectangle and collision property, and this is where i get me. Would any of you be able to spare some time and go over this with me ? I will post some code later Regards Del

  Read the article

• Using 2d collision with 3d objects

  - by Lyise

  I'm planning to write a fairly basic scrolling shoot 'em up, however, I have run into a query with regards to checking for collision. I plan to have a fixed top down view, where the player and enemies are all 3d objects on a fixed plane, and when the enemy or player fires at the other, their shots will also be along this fixed plane. In order to handle the collision, I have read up a bit on collision detection in 3d, as it is not something I have looked into previously, but I'm not sure what would be ideal for this situation. My options appear to be: Sphere collision, however, this lacks the pixel precision I would like Detection using all vertexes and planes of each object, but this seems overly convoluted for a fixed plane of play Rendering the play screen in black and white (where white is an object, black is empty space), once for enemies and once for the player, and checking for collisions that way (if a pixel is white on both, there is a collision) Which of these would be the best approach, or is there another option that I am missing? I have done this previously using 2d sprites, however I can't use the same thinking here as I don't have the image to refer to.

  Read the article

• Using a service registry that doesn’t suck Part III: Service testing is part of SOA governance

  - by gsusx

  This is the third post of this series intended to highlight some of the principles of modern SOA governance solution. You can read the first two parts here: Using a service registry that doesn’t suck part I: UDDI is dead Using a service registry that doesn’t suck part II: Dear registry, do you have to be a message broker? This time I’ve decided to focus on what of the aspects that drives me ABSOLUTELY INSANE about traditional SOA Governance solutions: service testing or I should I say the lack of...(read more)

  Read the article

< Previous Page | 1 2 3 4 5 6 7 8 9 10 11 12  | Next Page >