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  • Draw contour around object in Opengl

    - by Maciekp
    I need to draw contour around 2d objects in 3d space. I tried drawing lines around object(+points to fill the gap), but due to line width, some part of it(~50%) was covering object. I tried to use stencil buffer, to eliminate this problem, but I got sth like this(contour is green): http://goo.gl/OI5uc (sorry I can't post images, due to my reputation) You can see(where arrow points), that some parts of line are behind object, and some are above. This changes when I move camera, but always there is some part, that is covering it. Here is code, that I use for drawing object: glColorMask(1,1,1,1); std::list<CObjectOnScene*>::iterator objIter=ptr->objects.begin(),objEnd=ptr->objects.end(); int countStencilBit=1; while(objIter!=objEnd) { glColorMask(1,1,1,1); glStencilFunc(GL_ALWAYS,countStencilBit,countStencilBit); glStencilOp(GL_REPLACE,GL_KEEP,GL_REPLACE ); (*objIter)->DrawYourVertices(); glStencilFunc(GL_NOTEQUAL,countStencilBit,countStencilBit); glStencilOp(GL_KEEP,GL_KEEP,GL_REPLACE); (*objIter)->DrawYourBorder(); ++objIter; ++countStencilBit; } I've tried different settings of stencil buffer, but always I was getting sth like that. Here is question: 1.Am I setting stencil buffer wrong? 2. Are there any other simple ways to create contour on such objects? Thanks in advance.

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  • How does opengl-es 2 assemble primitives?

    - by stephelton
    Two things I'm quite confused about. 1) OpenGL ES 2.0 creates primitives before the vertex shader is invoked. Why, then, does it not automatically provide the vertex shader the position of the vertex? 2) OpenGL ES 2.0 supports glDrawElements(), but it does not support glEnableClientState() or GL_VERTEX_ARRAY, so how can this call possibly be used to construct primitives? NOTE: this is OpenGL ES 2.0, NOT normal OpenGL! Thanks!

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  • Game Editor - When screen is clicked, how do you identify which object that is clicked?

    - by Deukalion
    I'm trying to create a Game Editor, currently just placing different types of Shapes and such. I'm doing this in Windows Forms while drawing the 3D with XNA. So, if I have a couple of Shapes on the screen and I click the screen I want to be able to identify "which" of these objects you clicked. What is the best method for this? Since having two objects one behind the other, it should be able to recognize the one in front and not the one behind it and also if I rotate the camera and click on the one behind it - it should identify it and not the first one. Are there any smart ways to go about this?

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  • Alternatives to the GPL

    - by Bane
    I made a game, and I am currently making a game engine. I want them both to be completely free and open source. What license should I choose? I was reading a bit on GPL, but that seems to be more suited for system code and libraries, AFAIK, as it doesn't permit the use of code for proprietorial software - which, in turn, implies that the code can be used in the first place. I can see that, obviously, game engines can be considered libraries, and therefor be used, but what about game code? Is there an alternative to GPL?

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  • Unity3D Android - Move your character to a specific x position

    - by user3666251
    Im making a new game for android and I wanted to move my character (which is a cube for now) to a specific x location (on top of a flying floor/ground thingy) but I've been having some troubles with it.I've been using this script : var jumpSpeed: float = 3.5; var distToGround: float; function Start(){ // get the distance to ground distToGround = collider.bounds.extents.y; } function IsGrounded(): boolean { return Physics.Raycast(transform.position, -Vector3.up, distToGround + 0.1); } function Update () { // Move the object to the right relative to the camera 1 unit/second. transform.Translate(Vector3.forward * Time.deltaTime); if (Input.anyKeyDown && IsGrounded()){ rigidbody.velocity.x = jumpSpeed; } } And this is the result (which is not what I want) : https://www.youtube.com/watch?v=Fj8B6eI4dbE&feature=youtu.be Anyone has any idea how to do this ? Im new in unity and scripting.Im using java btw. Ty.

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  • Odds For Fighting Game

    - by thinkfuture
    I'm creating a fighting game where two opponents face off against each other in the ring. While I've been able to figure out the odds of a player winning based on previous wins/losses, I have yet to find a formula which modifies those odds based on opponent. For example: Player 1: W:5 L:5 - 1/1 odds Player 2: W:5 L:0 - 1/5 odds I want to calculate the odds that Player 1 will wins against player 2. Compounding this the players could be of different levels: if the players are within a few levels of each other, the odds should map closely to wins/losses. However, as the levels diverge, the odds of the lower level player winning reduce. As a swag: Player 1 - W:5 L:5 - 1:1 odds Against a level 8 - 1:2 Against a level 9 - 2:3 Against a level 10 - 1:1 Against a level 11 - 3:2 Against a level 12 - 2:1 These are just estimates, my sense is that there is a math formula out there which will calculate that - can anyone out there point me to what this could be? Thanks...Chris

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  • GestureListener's fling method doesn't get called

    - by nosferat
    I'm using SimpleGestureDetector from the libgdx-users Wiki as my InputProcessor. I set it in the created() method: Gdx.input.setInputProcess(new SimpleDirectionGestureDetector(charController)); charController is my class which implements the DirectionListener interface defined in the SimpleDirectionGestureDetector class and it is responsible for moving the player character. However the character doesn't change direction when I'm performing a fling action in any direction. I've checked and the fling() method in the SimpleDirectionGesture class doesn't get called and I have no idea why, since everything seems good. What am I doing wrong?

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  • How should I organize my matrices in a 3D game engine?

    - by Need4Sleep
    I'm working with a group of people from around the world to create a game engine (and hopefully a game with it) within the next upcoming years. My first task is to write a camera class for the engine to use in order to add cameras to the scene, with position and follow points. The problem I have is with using matrices for transformations in the class, should I keep matrices separate to each class? Such as have the model matrix in the model class, camera matrix in the camera class, or have all matrices placed in one class/chuck? I could see pros and cons for each method, but I wanted to hear some input form a more professional standpoint.

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  • HTML5 clicking objects in canvas

    - by Dave
    I have a function in my JS that gets the user's mouse click on the canvas. Now lets say I have a random shape on my canvas (really its a PNG image which is rectangular) but i don't want to include any alpha space. My issue lies with lets say i click some where and it involves a pixel of one of the images. The first issue is how do you work out the pixel location is an object on the map (and not the grass tiles behind). Secondly if i clicked said image, if each image contains its own unique information how do you process the click to load the correct data. Note I don't use libraries I personally prefer the raw method. Relying on libraries doesn't teach me much I find.

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  • Turn-Based RPG Battle Instance Layout For Larger Groups

    - by SoulBeaver
    What a title, eh? I'm currently designing a videogame; a turn-based RPG like Final Fantasy (because everybody knows Final Fantasy). It's a 2D sprite game. These are my ideas for combat: -The player has a group of 15 members (main character included) -During battle, five of the group are designated as active, and appear in the battle. -These five may be switched out at leisure, or when one of the five die. -At any time, the Waiting members can cast buffs, be healed by the active members, or perform special attacks. -Battles should contain 10+ monsters at least. I'm aiming for 20, but I'm not sure if that's possible yet. -Battles should feel larger than normal due to the interaction of Waiting members, active members and the increased amount of monsters per battle. -The player has two rows in which to put the Active members: front and back. -Depending on the implementation, I might allow comboing of player attacks and skills. These are just design ideas, so beware! I have not been able to test this out yet- I have no idea yet if any of these ideas bunched together will make for a compelling game. What sounds good on paper doesn't necessarily have to be good in practice! What I'm asking now is how to create the layout for this. My starting point are the battles in Final Fantasy VI, with up to 5-6 monsters on the left and the characters on the right- monsters on both sides if it's a pincer attack. However, this view would not work feasible with my goal of 20 monsters and 5 characters. All the monsters on the left would appear cluttered unless I scale them far far back. If I create a pincer-like map, then there would be no real pincer-attack possible. If I space the monsters out I force the player to scroll the screen- a game mechanic I've come across and not enjoyed imho. My question is: does anybody have any layouts or guides for designing battle maps in turn-based RPGs, especially with a larger number of enemies taken into consideration? How should it look? I am not asking for specific combat mechanics, just the layout for the moment.

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  • Finding inspiration / help for making up (weapon) names

    - by Rookie
    I'm really bad with words, especially with English words. Currently I'm struggling to make a good weapon names for my game, it needs to display the weapon functionality (weak/strong/fast/ballistic etc) correctly as well. For example the best weapon in a (futuristic) game cannot be called just with the name "Laser", it's just too boring, right? Are there any tools, websites or anything that helps me finding good names for weapons? (or anything else similar). I was thinking to use scientific names, but noticed that they are really hard to write, and they get very long, and I also lack information about science, I only know I could use the atomic sub-particles names in the weapons for example. How do I get started with becoming good with making up names? (this could apply in generally to any naming problems).

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  • Getting a texture from a renderbuffer in OpenGL?

    - by Rushyo
    I've got a renderbuffer (DepthStencil) in an FBO and I need to get a texture from it. I can't have both a DepthComponent texture and a DepthStencil renderbuffer in the FBO, it seems, so I need some way to convert the renderbuffer to a DepthComponent texture after I'm done with it for use later down the pipeline. I've tried plenty of techniques to grab the depth component from the renderbuffer for weeks but I always come out with junk. All I want at the end is the same texture I'd get from an FBO if I wasn't using a renderbuffer. Can anyone post some comprehensive instructions or code that covers this seemingly simple operation? EDIT: Linky to an extract version of the code http://dl.dropbox.com/u/9279501/fbo.cs Screeny of the Depth of Field effect + FBO - without depth(!) http://i.stack.imgur.com/Hj9Oe.jpg Screeny without Depth of Field effect + FBO - depth working fine http://i.stack.imgur.com/boOm1.jpg

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  • Extracting Frustum Planes (Hartmann & Gribbs method)

    - by DAVco
    I have been grappling with the Hartmann/Gribbs method of extracting the Frustum planes for some time now, with little success. There doesn't appear to be a "definitive" topic or tutorial which combines all the necessary information, so perhaps this can be it First of all, I am attempting to do this in C# (For Playstation Mobile), using OpenGL style Column-Major matrices in a Right-Handed coordinate system but obviously the math will work in any language. My projection matrix has a Near plane at 1.0, Far plane at 1000, FOV of 45.0 and Aspect of 1.7647. I want to get my planes in World-Space, so I build my frustum from the View-Projection Matrix (that's projectionMatrix * viewMatrix). The view Matrix is the inverse of the camera's World-Transform. The problem is; regardless of what I tweak, I can't seem to get a correct frustum. I think that I may be missing something obvious. Focusing on the Near and Far planes for the moment (since they have the most obvious normals when correct), when my camera is positioned looking down the negative z-axis, I get two planes facing in the same direction, rather than opposite directions. If i strafe my camera left and right (while still looking along the z axis) the x value of the normal vector changes. Obviously, something is fundamentally wrong here; I just can't figure out what - maybe someone here can?

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  • Where does the light come from, using Maya/Panda3D?

    - by Aerovistae
    Total noob to Maya. Total noob to Panda3D. Planning on becoming really good at both as soon as I have free time to do so, but right now I have an assignment due in a few hours which requires this: (The part which confuses me is bolded.) Model and texture a vehicle and two different obstacles Build a scene graph in Panda with a plane, the vehicle, several copies of each of the obstacles, and (at least) a direction light Program vehicle movement, constrained to a plane (no terrain) Working headlights Vehicle collides with obstacles How do I attach a light source to a model? I'm assuming this is done in Panda3D but I'm sufficiently new to this that I wouldn't be astonished to hear it's part of the model.

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  • Pathfinding with MicroPather : costs calculations with sectors and portals

    - by Adan
    Hello, I'm considering using micropather to help me with pathfinding. I'm not using a discrete map : I'm working in 2d with sectors and portales. However, I'm just wondering what is the best way to compute costs with this library in this context. Just to be more clear about geometrical shapes I'm using : sectors are basically convex polygons, and portals are segments that lies on sector's edge. Micropather exposes a pure virtual Graph class that you must inherate and overrides 3 functions. I understand how pathfinding works, so there's no problem in overriding those functions. Right now, my implementation give me results, i.e I'm able to find a path in my map, but I'm not sure I'm using an optimal solution. For the AdjacentCost method : I just take the distance between sector's centers as the cost. I think a better solution should be to use the portal between the two sectors, compute its center, and then the cost should be : distance( sector A center, portal center ) + distance ( sector B center, portal center ). I'm pretty sure the approximation I'm using with just sector's center is enough for most cases, but maybe with thin and long sectors that are perpendicular, this approximation could mislead the A* algorithm. For the LeastCostEstimate method : I just take the midpoint of the two sectors. So, as you understand, I'm always working with sectors' centers, and it's working fine. And I'm pretty sure there's a better way to work. Any suggestions or feedbacks? Thanks in advance!

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  • What are good JS libraries for game dev? (HTML5)

    - by acidzombie24
    If i decide to write a simple game both text and graphical (2d) what libs may i use? Assuming we are using a HTML5 compatible browser. The main things i can think of Rendering text on screen Animating sprites (using images/css) Input (capturing the arrow keys and getting relative mouse positions) Perhaps some preloading resource or dynamically loading resources and choosing order Sound (but i am unsure how important this will be to me at first). Perhaps with mixing and chaining sounds or looping forever until stop. Networking (low priority) to connect a user to another or to continuously GET data without multiple request (i know this exist but i dont know how easy it is to setup or use. But this isnt important to me. Its for the question).

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  • Kinect joint coordinates and XNA animation

    - by Sweta Dwivedi
    I have written a program to record the x,y,z coordinated of the Hand joint and I want to animate my models 2D or 3D according to these coordinates. . .However the output of the x,y,z coordinates are fluctuating from -0 to 1 but not more than that.. So i assume I will need to multiply them back with the screen width and height, however it still doesnt seem to animate according to the original x,y,z points Any transformations I might be missing out? while ((line = r.ReadLine()) != null) { string[] temp = line.Split(','); int x = (int) float.Parse(temp[0]))* maxWidth); int y = (int) float.Parse(temp[1])) * maxHeight); }

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  • JBox2D applyLinearImpulse doesn't work

    - by Romeo
    So i have this line of code: if(input.isKeyDown(Input.KEY_W)&&canJump()) { body.applyLinearImpulse(new Vec2(0, 30), cam.screenToWorld(body.getPosition())); System.out.println("I can jump!"); } My problem is that the console display I can jump! but the body doesn't do that. Can you explain to me if i do something wrong? Some more code. This function creates my 'hero' the one supposed to jump. private Body setDynamic(float width, float height, float x, float y) { PolygonShape shape = new PolygonShape(); shape.setAsBox(width/2, height/2); BodyDef bd = new BodyDef(); bd.allowSleep = true; bd.position = new Vec2(cam.screenToWorld(new Vec2(x + width / 2, y + height / 2))); bd.type = BodyType.DYNAMIC; bd.userData = new BodyInfo(width, height); Body body = world.createBody(bd); body.createFixture(shape, 10); return body; } And this is the main update loop: if(input.isKeyDown(Input.KEY_A)) { body.setLinearVelocity(new Vec2(-10*delta, body.getLinearVelocity().y)); } else if (input.isKeyDown(Input.KEY_D)) { body.setLinearVelocity(new Vec2(10*delta, body.getLinearVelocity().y)); } else { body.setLinearVelocity(new Vec2(0, body.getLinearVelocity().y)); } if(input.isKeyDown(Input.KEY_W)&&canJump()) { body.applyLinearImpulse(new Vec2(0, 30), body.getPosition()); System.out.println("I can jump!"); } world.step(delta * 0.001f, 10, 5); }

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  • XNA model drawing problem

    - by user1990950
    When using this code: public static void DrawModel(Model model, Vector3 position, Vector3 offset, float xRotation, float yRotation, float zRotation, float allrot, float xScale, float yScale, float zScale) { position.Y *= -1; offset.Y *= -1; Matrix worldMatrix = ((Matrix.CreateRotationZ(MathHelper.ToRadians(zRotation)) * Matrix.CreateRotationX(MathHelper.ToRadians(xRotation))) * Matrix.CreateRotationY(MathHelper.ToRadians(yRotation))) * (Matrix.CreateTranslation(offset) * Matrix.CreateRotationY(MathHelper.ToRadians(allrot))) * Matrix.CreateScale(xScale, yScale, zScale); worldMatrix *= Matrix.CreateTranslation(position) * theCamera.GetTransformation() * Matrix.CreateTranslation(new Vector3(-(graphics.GraphicsDevice.Viewport.Width / 2), graphics.GraphicsDevice.Viewport.Height / 2, 0)); foreach (ModelMesh mesh in model.Meshes) { for (int i = 0; i < mesh.Effects.Count; i++) { ((BasicEffect)mesh.Effects[i]).EnableDefaultLighting(); ((BasicEffect)mesh.Effects[i]).World = worldMatrix; ((BasicEffect)mesh.Effects[i]).View = viewMatrix; ((BasicEffect)mesh.Effects[i]).Projection = projectionMatrix; } mesh.Draw(); } } The model rotates and then scales. It should scale and then rotate, but whenever I try to change it, it won't work.

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  • two-part dice pool mechanic

    - by bythenumbers
    I'm working on a dice mechanic/resolution system based off of the Ghost/Echo (hereafter shortened to G/E) tabletop RPG. Specifically, since G/E can be a little harsh with dealing out consequences and failure, I was hoping to soften the system and add a little more player control, as well as offer the chance for players to evolve their characters into something unique, right from creation. So, here's the mechanic: Players roll 2d12 against the two statistics for their character (each is a number from 2-11, and may be rolled above or below depending on the nature of the action attempted, rolling your stat exactly always fails). Depending on the success for that roll, they add dice to the pool rolled for a modified G/E style action. The acting player gets two dice anyhow, and I am debating offering a bonus die for each success, or a single bonus die for succeeding on both of the statistic-compared rolls. One the size of the dice pool is set, the entire pool is rolled, and the players are allowed to assign rolled dice to a goal and a danger. Assigned results are judged as follows: 1-4 means the attempted goal fails, or the danger comes true. 5-8 is a partial success at the goal, or partially avoiding the danger. 9-12 means the goal is achieved, or the danger avoided. My concerns are twofold: Firstly, that the two-stage action is too complicated, with two rolls to judge separately before anything can happen. Secondly, that the statistics involved go too far in softening the game. I've run some basic simulations, and the approximate statistics follow: 2 dice (up to) 3 dice (up to) 4 dice failure ~33% ~25% ~20% partial ~33% ~35% ~35% success ~33% ~40% ~45% I'd appreciate any advice that addresses my concerns or offers to refine my simulation (right now the first roll is statistically modeled as sign(1d12-1d12), where 0 is a success).

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  • Rotation matrix for a 3D vector

    - by Shashwat
    I have a direction vector on which I have to apply some rotation to align it to positive z-axis. To use Matrix.CreateRotationX(angle) of XNA, I need the angle for which I'd have to compute cos or tan inverse. I think this is a complex task to do. Also, eventually those are also converted to sin(angle) and cos(angle) in the matrix. Is there any inbuilt way to create rotation matrix from a 3D vector? However, I can write the function but still asking if there is one already there.

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  • How do I efficiently generate chunks to fill entire screen when my player moves?

    - by Trixmix
    In my game I generate chunks when the player moves. The chunks are all generated on the fly, but currently I just created a simple flat 8X8 floor. What happens is that when he moves to a new chunk the chunk in the direction of the player gets generated and its neighboring chunks. This is not efficient because the generator does not fill the entire screen. I did try to use recursion but its not as fast as I would like it to be. My question is what would be an efficient way of doing so? How does minecraft do so? When I say this I mean just the way it PICKS which chunks to generate and in what order. Not how they generate or how they are saved in regions, just the order/way it generates them. I just want to know what is a good way to load chunks around the player.

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  • How should I structure moving from overworld to menu system / combat?

    - by persepolis
    I'm making a text-based "Arena" game where the player is the owner of 5 creatures that battle other teams for loot, experience and glory. The game is very simple, using Python and a curses emulator. I have a static ASCII map of an "overworld" of sorts. My character, represented by a glyph, can move about this static map. There are locations all over the map that the character can visit, that break down into two types: 1) Towns, which are a series of menus that will allow the player to buy equipment for his team, hire new recruits or do other things. 2) Arenas, where the player's team will have a "battle" interface with actions he can perform, messages about the fight, etc. Maybe later, an ASCII representation of the fight but for now, just screens of information with action prompts. My main problem is what kind of design or structure I should use to implement this? Right now, the game goes through a master loop which waits for keyboard input and then moves the player about the screen. My current thinking is this: 1) Upon keyboard input, the Player coordinates are checked against a list of Location objects and if the Player coords match the Location coords then... 2) ??? I'm not sure if I should then call a seperate function to initiate a "menu" or "combat" mode. Or should I create some kind of new GameMode object that contains a method itself for drawing the screen, printing the necessary info? How do I pass my player's team data into this object? My main concern is passing around the program flow into all these objects. Should I be calling straight functions for different parts of my game, and objects to represent "things" within my game? I was reading about the MVC pattern and how this kind of problem might benefit - decouple the GUI from the game logic and user input but I have no idea how this applies to my game.

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  • Box2D Difference Between WorldCenter and Position

    - by Free Lancer
    So this problem has been brothering for a couple of days now. First off, what is the difference between say Body.getWorldCenter() and Body.getPosition(). I heard that WorldCenter might have to do with the center of gravity or something. Second, When I create a Box2D Body for a sprite the Body is always at the lower left corner. I check it by printing a Rectangle of 1 pixel around the box.getWorldCenter(). From what I understand the Body should be in the center of the Sprite and its bounding box should wrap around the Sprite, correct? Here's an image of what I mean (The Sprite is Red, Body Blue): Here's some code: Body Creator: public static Body createBoxBody( final World pPhysicsWorld, final BodyType pBodyType, final FixtureDef pFixtureDef, Sprite pSprite ) { float pRotation = 0; float pCenterX = pSprite.getX() + pSprite.getWidth() / 2; float pCenterY = pSprite.getY() + pSprite.getHeight() / 2; float pWidth = pSprite.getWidth(); float pHeight = pSprite.getHeight(); final BodyDef boxBodyDef = new BodyDef(); boxBodyDef.type = pBodyType; //boxBodyDef.position.x = pCenterX / Constants.PIXEL_METER_RATIO; //boxBodyDef.position.y = pCenterY / Constants.PIXEL_METER_RATIO; boxBodyDef.position.x = pSprite.getX() / Constants.PIXEL_METER_RATIO; boxBodyDef.position.y = pSprite.getY() / Constants.PIXEL_METER_RATIO; Vector2 v = new Vector2( boxBodyDef.position.x * Constants.PIXEL_METER_RATIO, boxBodyDef.position.y * Constants.PIXEL_METER_RATIO ); Gdx.app.log("@Physics", "createBoxBody():: Box Position: " + v); // Temporary Box shape of the Body final PolygonShape boxPoly = new PolygonShape(); final float halfWidth = pWidth * 0.5f / Constants.PIXEL_METER_RATIO; final float halfHeight = pHeight * 0.5f / Constants.PIXEL_METER_RATIO; boxPoly.setAsBox( halfWidth, halfHeight ); // set the anchor point to be the center of the sprite pFixtureDef.shape = boxPoly; final Body boxBody = pPhysicsWorld.createBody(boxBodyDef); Gdx.app.log("@Physics", "createBoxBody():: Box Center: " + boxBody.getPosition().mul(Constants.PIXEL_METER_RATIO)); boxBody.createFixture(pFixtureDef); boxBody.setTransform( boxBody.getWorldCenter(), MathUtils.degreesToRadians * pRotation ); boxPoly.dispose(); return boxBody; } Making the Sprite: public Car( Texture texture, float pX, float pY, World world ) { super( "Car" ); mSprite = new Sprite( texture ); mSprite.setSize( mSprite.getWidth() / 6, mSprite.getHeight() / 6 ); mSprite.setPosition( pX, pY ); mSprite.setOrigin( mSprite.getWidth()/2, mSprite.getHeight()/2); FixtureDef carFixtureDef = new FixtureDef(); // Set the Fixture's properties, like friction, using the car's shape carFixtureDef.restitution = 1f; carFixtureDef.friction = 1f; carFixtureDef.density = 1f; // needed to rotate body using applyTorque mBody = Physics.createBoxBody( world, BodyDef.BodyType.DynamicBody, carFixtureDef, mSprite ); }

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  • D3DXMatrixDecompose gives different quaternion than D3DXQuaternionRotationMatrix

    - by Fraser
    In trying to solve this problem, I tracked down the problem to the conversion of the rotation matrix to quaternion. In particular, consider the following matrix: -0.02099178 0.9997436 -0.008475631 0 0.995325 0.02009799 -0.09446743 0 0.09427284 0.01041905 0.9954919 0 0 0 0 1 SlimDX.Quaternion.RotationMatrix (which calls D3DXQuaternionRotationMatrix gives a different answer than SlimDX.Matrix.Decompose (which uses D3DXMatrixDecompose). The answers they give (after being normalized) are: X Y Z W Quaternion.RotationMatrix -0.05244324 0.05137424 0.002209336 0.9972991 Matrix.Decompose 0.6989997 0.7135442 -0.03674842 -0.03006023 Which are totally different (note the signs of X, Z, and W are different). Note that these aren't q/-q (two quaternions that represent the same rotation); they face completely different directions. I've noticed that with matrices for rotations very close to that one (successive frames in the animation) that the Matrix.Decompose version gives a solution that flips around wildly and occasionally goes into the desired position, while the Quaternion.RotationMatrix version gives solutions that are stable but go in the wrong direction. This is only for the right arm in my animation -- for the left arm, both functions give the correct solution, which is the same quaternion within error tolerances. This makes me think that there's some sort of numeric instability or weird stuff with signs going on. I tried implementing this and then this, but both gave me a completely incorrect solution (even for the matricies where the SlimDX ones were working correctly) -- maybe the rows and columns are flipped?

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