Search Results

Search found 37616 results on 1505 pages for 'model driven development'.

Page 579/1505 | < Previous Page | 575 576 577 578 579 580 581 582 583 584 585 586  | Next Page >

• In a browser, is it best to use one huge spritesheet or many (10000) different PNG's?

  - by Nick

  I'm creating a game in jQuery, where I use about 10000 32x32 tiles. Until now, I have been using them all separately (no sprite sheet). An average map uses about 2000 tiles (sometimes re-used PNG's but all separate divs) and the performance ranges from stable (Chrome) to a bit laggy (Firefox). Each of these divs are positioned absolutely using CSS. They do not need to be updated every tick, just when a new map is loaded. Would it be better for performance to use spritesheet methods for the divs using CSS background-positioning, like gameQuery does? Thank you in advance!

  Read the article

• RPG level-experience formula [closed]

  - by Comy

  I want to make an RPG game and I would like an advice on how should I create my level-experience formula. I saw this formula http://rsdo.net/rsdonline/guides/Experience%20formula.html#PHP and I created a formula myself and I want to ask you which would be better. RuneScape rates My rates Level 2 - 83 xp Level 2 - 35 Level 3 - 174 xp Level 3 - 84 Level 4 - 276 xp Level 4 - 150 Level 5 - 388 xp Level 5 - 238 Level 10 - 1,154 xp Level 10 - 1,087 Level 100 - 14,391,160 xp Level 100 - 311,017 As you can see at level 100 RuneScape's xp is very big and my level 100 is equal with RuneScape's Level 61. Is it better if the xp grows very fast at one point or depends on how I make my game?

  Read the article

• Easiest turn-base games you can think of?

  - by Edgar Miranda

  I'm planning to get into the process of programming multiplayer turn-base games. I would like to start off by making some of the simplest (yet fun) multiplayer turn-base games out there. What are some that you can provide? For example... Tic-Tac-Toe Rock-Paper-Scissors Checkers Some not so easy games... 4 in a row chess poker In terms of "ease" of implementation I'm mainly looking at logic. For example, Rock-Paper-Scissors has very simple logic, while chess has logic that is more complicated. So far I have the following: Hexagon Heroes of Might and Magic Nine Men's Morris Connect 4 21 (card game) Pen the Pig (The Dot game) Memory Match

  Read the article

• Logging library for (c++) games

  - by Klaim

  I know a lot of logging libraries but didn't test a lot of them. (GoogleLog, Pantheios, the coming boost::log library...) In games, especially in remote multiplayer and multithreaded games, logging is vital to debugging, even if you remove all logs in the end. Let's say I'm making a PC game (not console) that needs logs (multiplayer and multithreaded and/or multiprocess) and I have good reasons for looking for a library for logging (like, I don't have time or I'm not confident in my ability to write one correctly for my case). Assuming that I need : performance ease of use (allow streaming or formating or something like that) reliable (don't leak or crash!) cross-platform (at least Windows, MacOSX, Linux/Ubuntu) Wich logging library would you recommand? Currently, I think that boost::log is the most flexible one (you can even log to remotely!), but have not good performance. Pantheios is often cited but I don't have comparison points on performance and usage. I've used my own lib for a long time but I know it don't manage multithreading so it's a big problem, even if it's fast enough. Google Log seems interesting, I just need to test it but if you already have compared those libs and more, your advice might be of good use. Games are often performance demanding while complex to debug so it would be good to know logging libraries that, in our specific case, have clear advantages.

  Read the article

• Draw order in XNA

  - by Petr Abdulin

  It is possible to set draw order of a DrawableGameComponent by setting DrawOrder property. But is it possible to set draw order of "main" Game class? I have 2 DrawableGameComponents, and Draw method of a main Game class is called first, while I want it to be the last. Should I just mode all "main" draw code to another component and set it DrawOrder? Answer: seems like I'm just confused myself a little. Black on black, that's why I didn't saw it. Main Draw is called last, as expected.

  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 detection code style

  - by Marian Ivanov

  Not only there are two useful broad-phase algorithms and a lot of useful narrowphase algorithms, there are also multiple code styles. Arrays vs. calling Make an array of broadphase checks, then filter them with narrowphase checks, then resolve them. function resolveCollisions(thingyStructure * a,thingyStructure * b,int index){ possibleCollisions = getPossibleCollisions(b,a->get(index)); for(i=0; i<possibleCollitionsNumber; i++){ if(narrowphase(possibleCollisions[i],a[index])) { collisions->push(possibleCollisions[i]); }; }; for(i=0; i<collitionsNumber; i++){ //CODE FOR RESOLUTION }; }; Make the broadphase call the narrowphase, and the narrowphase call the resolution function resolveCollisions(thingyStructure * a,thingyStructure * b,int index){ broadphase(b,a->get(index)); }; function broadphase(thingy * with, thingy * what){ while(blah){ //blahcode narrowphase(what,collidingThing); }; }; Events vs. in-the-loop Fire an event. This abstracts the check away, but it's trickier to make an equal interaction. a[index] -> collisionEvent(eventdata); //much later int collisionEvent(eventdata){ //resolution gets here } Resolve the collision inside the loop. This glues narrowphase and resolution into one layer. if(narrowphase(possibleCollisions[i],a[index])) { //CODE GOES HERE }; The questions are: Which of the first two is better, and how am I supposed to make a zero-sum Newtonian interaction under B1.

  Read the article

• How do I know if my game's average game session time is too small?

  - by you786

  My game has only one life, and the aim is to stay alive as long as possible to get as many points as possible (it's an endless runner). Using Google Analytics I found that players are staying alive for an average of 17 seconds. I could easily increase or decrease this by manipulating acceleration or starting speed. The question is, should I change it at all? Is there any research or general ideas on the best playing time for a game like this? I would also like to know about any research about how long an ideal mobile game session should last.

  Read the article

• How to loop section from a song correctly?

  - by Teflo

  I'm programming a little Music Engine for my game in C# and XNA, and one aspect from it is the possibility to loop a section from a song. For example, my song has an intropart, and when the song reached the end ( or any other specific point ), it jumps back where the intropart is just over. ( A - B - B - B ... ) Now I'm using IrrKlank, which is working perfectly, without any gaps, but I have a problem: The point where to jump back is a bit inaccurate. Here's some example code: public bool Passed(float time) { if ( PlayPosition >= time ) return true; return false; } //somewhere else if( song.Passed( 10.0f ) ) song.JumpTo( 5.0f ); Now the problem is, the song passes the 10 seconds, but play a few milliseconds until 10.1f or so, and then jumps to 5 seconds. It's not that dramatic, but very incorrect for my needs. I tried to fix it like that: public bool Passed( float time ) { if( PlayPosition + 3 * dt >= time && PlayPosition <= time ) return true; return false; } ( dt is the delta time, the elapsed time since the last frame ) But I don't think, that's a good solution for that. I hope, you can understand my problem ( and my english, yay /o/ ) and help me :)

  Read the article

• OpenGL ES Loading

  - by kuroutadori

  I want to know what is the norm of loading rendering code. Take a button. When the application is loaded, a texture is loaded which has the image of the button on it. When the button is tapped, it then adds a loader into a queue, which is loaded on render thread. It then loads up an array buffer with vertexes and tex coords when render is called. It then adds to a render tree. Then it renders. the render function looks like this void render() { update(); mBaseRenderer->render(); } update() is when the queue is checked to see if anything needs loading. mBaseRenderer->render() is the render tree. What I am asking then is, should I even have the update() there at all and instead have everything preloaded before it renders? If I can have it loaded when need, for instance when there is tap, then how can it be done (My current code causes an dequeueing buffer error (Unknown error: -75) which I assume is to do with OpenGL ES and the context)?

  Read the article

• Automatically zoom out the camera to show all players (XNA)

  - by user36159

  I am building a game in XNA that takes place in a rectangular arena. The game is multiplayer and each player may go where they like within the arena. The camera is a persepective camera that looks directly downwards. The camera should be automatically repositioned based on the game state. Currently, the xy position is a weighted sum of the xy positions of important entities. I would like the camera's z position to be calculated from the xy coordinates so that it zooms out to the point where all important entities are visible. My current approach is to: hw = the greatest x distance from the camera to an important entity hh = the greatest y distance from the camera to an important entity Calculate z = max(hw / tan(FoVx), hh / tan(FoVy)) My code seems to almost work as it should, but the resulting z values are always too low by a factor of about 4. Any ideas?

  Read the article

• Multiple setInterval in a HTML5 Canvas game

  - by kushsolitary

  I'm trying to achieve multiple animations in a game that I am creating using Canvas (it is a simple ping-pong game). This is my first game and I am new to canvas but have created a few experiments before so I have a good knowledge about how canvas work. First, take a look at the game here. The problem is, when the ball hits the paddle, I want a burst of n particles at the point of contact but that doesn't came right. Even if I set the particles number to 1, they just keep coming from the point of contact and then hides automatically after some time. Also, I want to have the burst on every collision but it occurs on first collision only. I am pasting the code here: //Initialize canvas var canvas = document.getElementById("canvas"), ctx = canvas.getContext("2d"), W = window.innerWidth, H = window.innerHeight, particles = [], ball = {}, paddles = [2], mouse = {}, points = 0, fps = 60, particlesCount = 50, flag = 0, particlePos = {}; canvas.addEventListener("mousemove", trackPosition, true); //Set it's height and width to full screen canvas.width = W; canvas.height = H; //Function to paint canvas function paintCanvas() { ctx.globalCompositeOperation = "source-over"; ctx.fillStyle = "black"; ctx.fillRect(0, 0, W, H); } //Create two paddles function createPaddle(pos) { //Height and width this.h = 10; this.w = 100; this.x = W/2 - this.w/2; this.y = (pos == "top") ? 0 : H - this.h; } //Push two paddles into the paddles array paddles.push(new createPaddle("bottom")); paddles.push(new createPaddle("top")); //Setting up the parameters of ball ball = { x: 2, y: 2, r: 5, c: "white", vx: 4, vy: 8, draw: function() { ctx.beginPath(); ctx.fillStyle = this.c; ctx.arc(this.x, this.y, this.r, 0, Math.PI*2, false); ctx.fill(); } }; //Function for creating particles function createParticles(x, y) { this.x = x || 0; this.y = y || 0; this.radius = 0.8; this.vx = -1.5 + Math.random()*3; this.vy = -1.5 + Math.random()*3; } //Draw everything on canvas function draw() { paintCanvas(); for(var i = 0; i < paddles.length; i++) { p = paddles[i]; ctx.fillStyle = "white"; ctx.fillRect(p.x, p.y, p.w, p.h); } ball.draw(); update(); } //Mouse Position track function trackPosition(e) { mouse.x = e.pageX; mouse.y = e.pageY; } //function to increase speed after every 5 points function increaseSpd() { if(points % 4 == 0) { ball.vx += (ball.vx < 0) ? -1 : 1; ball.vy += (ball.vy < 0) ? -2 : 2; } } //function to update positions function update() { //Move the paddles on mouse move if(mouse.x && mouse.y) { for(var i = 1; i < paddles.length; i++) { p = paddles[i]; p.x = mouse.x - p.w/2; } } //Move the ball ball.x += ball.vx; ball.y += ball.vy; //Collision with paddles p1 = paddles[1]; p2 = paddles[2]; if(ball.y >= p1.y - p1.h) { if(ball.x >= p1.x && ball.x <= (p1.x - 2) + (p1.w + 2)){ ball.vy = -ball.vy; points++; increaseSpd(); particlePos.x = ball.x, particlePos.y = ball.y; flag = 1; } } else if(ball.y <= p2.y + 2*p2.h) { if(ball.x >= p2.x && ball.x <= (p2.x - 2) + (p2.w + 2)){ ball.vy = -ball.vy; points++; increaseSpd(); particlePos.x = ball.x, particlePos.y = ball.y; flag = 1; } } //Collide with walls if(ball.x >= W || ball.x <= 0) ball.vx = -ball.vx; if(ball.y > H || ball.y < 0) { clearInterval(int); } if(flag == 1) { setInterval(emitParticles(particlePos.x, particlePos.y), 1000/fps); } } function emitParticles(x, y) { for(var k = 0; k < particlesCount; k++) { particles.push(new createParticles(x, y)); } counter = particles.length; for(var j = 0; j < particles.length; j++) { par = particles[j]; ctx.beginPath(); ctx.fillStyle = "white"; ctx.arc(par.x, par.y, par.radius, 0, Math.PI*2, false); ctx.fill(); par.x += par.vx; par.y += par.vy; par.radius -= 0.02; if(par.radius < 0) { counter--; if(counter < 0) particles = []; } } } var int = setInterval(draw, 1000/fps); Now, my function for emitting particles is on line 156, and I have called this function on line 151. The problem here can be because of I am not resetting the flag variable but I tried doing that and got more weird results. You can check that out here. By resetting the flag variable, the problem of infinite particles gets resolved but now they only animate and appear when the ball collides with the paddles. So, I am now out of any solution.

  Read the article

• 3D terrain map with Hexagon Grids (XNA)

  - by Rob

  I'm working on a hobby project (I'm a web/backend developer by day) and I want to create a 3D Tile (terrain) engine. I'm using XNA, but I can use MonoGame, OpenGL, or straight DirectX, so the answer does not have to be XNA specific. I'm more looking for some high level advice on how to approach this problem. I know about creating height maps and such, there are thousands of references out there on the net for that, this is a bit more specific. I'm more concerned with is the approach to get a 3D hexagon tile grid out of my terrain (since the terrain, and all 3d objects, are basically triangles). The first approach I thought about is to basically draw the triangles on the screen in the following order (blue numbers) to give me the triangles for terrain (black triangles) and then make hexes out of the triangles (red hex). http://screencast.com/t/ebrH2g5V This approach seems complicated to me since i'm basically having to draw 4 different types of triangles. The next approach I thought of was to use the existing triangles like I did for a square grid and get my hexes from 6 triangles as follows http://screencast.com/t/w9b7qKzVJtb8 This seems like the easier approach to me since there are only 2 types of triangles (i would have to play with the heights and widths to get a "perfect" hexagon, but the idea is the same. So I'm looking for: 1) Any suggestions on which approach I should take, and why. 2) How would I translate mouse position to a hexagon grid position (especially when moving the camera around), for example in the second image if the mouse pointer were the green circle, how would I determine to highlight that hexagon and then translating that into grid coordinates (assuming it is 0,0)? 3) Any references, articles, books, etc - to get me going in the right direction. Note: I've done hex grid's and mouse-grid coordinate conversion before in 2d. looking for some pointers on how to do the same in 3d. The result I would like to achieve is something similar to the following: http :// www. youtube .com / watch?v=Ri92YkyC3fw (sorry about the youtube link, but it will only let me post 2 links in this post... same rep problem i mention below...) Thanks for any help! P.S. Sorry for not posting the images inline, I apparently don't have enough rep on this stack exchange site.

  Read the article

• PokeMMO. How they do it?

  - by RufioLJ

  Well PokeMMO is a JAVA game project which basically is the original FireRed title for the GBA made online. They know this type of projects don't last long because of the copyrighted material used, but they somehow made their client extract resources from ROMS. So they don't offer any copyrighted material on their download. I wonder what technique they could be using for this? All I know is that they use LWJGL.

  Read the article

• how to add water effect to an image

  - by brainydexter

  This is what I am trying to achieve: A given image would occupy say 3/4th height of the screen. The remaining 1/4th area would be a reflection of it with some waves (water effect) on it. I'm not sure how to do this. But here's my approach: render the given texture to another texture called mirror texture (maybe FBOs can help me?) invert mirror texture (scale it by -1 along Y) render mirror texture at height = 3/4 of the screen add some sense of noise to it OR using pixel shader and time, put pixel.z = sin(time) to make it wavy (Tech: C++/OpenGL/glsl) Is my approach correct ? Is there a better way to do this ? Also, can someone please recommend me if using FrameBuffer Objects would be the right thing here ? Thanks

  Read the article

• Texture errors in CubeMap

  - by shade4159

  I am trying to apply this texture as a cubemap. This is my result: Clearly I am doing something with my texture coordinates, but I cannot for the life of me figure out what. I don't even see a pattern to the texture fragments. They just seem like a jumble of different faces. Can anyone shed some light on this? Vertex shader: #version 400 in vec4 vPosition; in vec3 inTexCoord; smooth out vec3 texCoord; uniform mat4 projMatrix; void main() { texCoord = inTexCoord; gl_Position = projMatrix * vPosition; } My fragment shader: #version 400 smooth in vec3 texCoord; out vec4 fColor; uniform samplerCube textures void main() { fColor = texture(textures,texCoord); } Vertices of cube: point4 worldVerts[8] = { vec4( 15, 15, 15, 1 ), vec4( -15, 15, 15, 1 ), vec4( -15, 15, -15, 1 ), vec4( 15, 15, -15, 1 ), vec4( -15, -15, 15, 1 ), vec4( 15, -15, 15, 1 ), vec4( 15, -15, -15, 1 ), vec4( -15, -15, -15, 1 ) }; Cube rendering: void worldCube(point4* verts, int& Index, point4* points, vec3* texVerts) { quadInv( verts[0], verts[1], verts[2], verts[3], 1, Index, points, texVerts); quadInv( verts[6], verts[3], verts[2], verts[7], 2, Index, points, texVerts); quadInv( verts[4], verts[5], verts[6], verts[7], 3, Index, points, texVerts); quadInv( verts[4], verts[1], verts[0], verts[5], 4, Index, points, texVerts); quadInv( verts[5], verts[0], verts[3], verts[6], 5, Index, points, texVerts); quadInv( verts[4], verts[7], verts[2], verts[1], 6, Index, points, texVerts); } Backface function (since this is the inside of the cube): void quadInv( const point4& a, const point4& b, const point4& c, const point4& d , int& Index, point4* points, vec3* texVerts) { quad( a, d, c, b, Index, points, texVerts, a.to_3(), b.to_3(), c.to_3(), d.to_3()); } And the quad drawing function: void quad( const point4& a, const point4& b, const point4& c, const point4& d, int& Index, point4* points, vec3* texVerts, const vec3& tex_a, const vec3& tex_b, const vec3& tex_c, const vec3& tex_d) { texVerts[Index] = tex_a.normalized(); points[Index] = a; Index++; texVerts[Index] = tex_b.normalized(); points[Index] = b; Index++; texVerts[Index] = tex_c.normalized(); points[Index] = c; Index++; texVerts[Index] = tex_a.normalized(); points[Index] = a; Index++; texVerts[Index] = tex_c.normalized(); points[Index] = c; Index++; texVerts[Index] = tex_d.normalized(); points[Index] = d; Index++; } Edit: I forgot to mention, in the image, the camera is pointed directly at the back face of the cube. You can kind of see the diagonals leading out of the corners, if you squint.

  Read the article

• Octree subdivision problem

  - by ChaosDev

  Im creating octree manually and want function for effectively divide all nodes and their subnodes - For example - I press button and subnodes divided - press again - all subnodes divided again. Must be like - 1 - 8 - 64. The problem is - i dont understand how organize recursive loops for that. OctreeNode in my unoptimized implementation contain pointers to subnodes(childs),parent,extra vector(contains dublicates of child),generation info and lots of information for drawing. class gOctreeNode { //necessary fields gOctreeNode* FrontBottomLeftNode; gOctreeNode* FrontBottomRightNode; gOctreeNode* FrontTopLeftNode; gOctreeNode* FrontTopRightNode; gOctreeNode* BackBottomLeftNode; gOctreeNode* BackBottomRightNode; gOctreeNode* BackTopLeftNode; gOctreeNode* BackTopRightNode; gOctreeNode* mParentNode; std::vector<gOctreeNode*> m_ChildsVector; UINT mGeneration; bool mSplitted; bool isSplitted(){return m_Splitted;} .... //unnecessary fields }; DivideNode of Octree class fill these fields, set mSplitted to true, and prepare for correctly drawing. Octree contains basic nodes(m_nodes). Basic node can be divided, but now I want recursivly divide already divided basic node with 8 subnodes. So I write this function. void DivideAllChildCells(int ix,int ih,int id) { std::vector<gOctreeNode*> nlist; std::vector<gOctreeNode*> dlist; int index = (ix * m_Height * m_Depth) + (ih * m_Depth) + (id * 1);//get index of specified node gOctreeNode* baseNode = m_nodes[index].get(); nlist.push_back(baseNode->FrontTopLeftNode); nlist.push_back(baseNode->FrontTopRightNode); nlist.push_back(baseNode->FrontBottomLeftNode); nlist.push_back(baseNode->FrontBottomRightNode); nlist.push_back(baseNode->BackBottomLeftNode); nlist.push_back(baseNode->BackBottomRightNode); nlist.push_back(baseNode->BackTopLeftNode); nlist.push_back(baseNode->BackTopRightNode); bool cont = true; UINT d = 0;//additional recursive loop param (?) UINT g = 0;//additional recursive loop param (?) LoopNodes(d,g,nlist,dlist); //Divide resulting nodes for(UINT i = 0; i < dlist.size(); i++) { DivideNode(dlist[i]); } } And now, back to the main question,I present LoopNodes, which must do all work for giving dlist nodes for splitting. void LoopNodes(UINT& od,UINT& og,std::vector<gOctreeNode*>& nlist,std::vector<gOctreeNode*>& dnodes) { //od++;//recursion depth bool f = false; //pass through childs for(UINT i = 0; i < 8; i++) { if(nlist[i]->isSplitted())//if node splitted and have childs { //pass forward through tree for(UINT j = 0; j < 8; j++) { nlist[j] = nlist[j]->m_ChildsVector[j];//set pointers to these childs } LoopNodes(od,og,nlist,dnodes); } else //if no childs { //add to split vector dnodes.push_back(nlist[i]); } } } This version of loop nodes works correctly for 2(or 1?) generations after - this will not divide neightbours nodes, only some corners. I need correct algorithm. Screenshot All I need - is correct version of LoopNodes, which can add all nodes for DivideNode.

  Read the article

• Breakout ball collision detection, bouncing against the walls

  - by Sri Harsha Chilakapati

  I'm currently trying to program a breakout game to distribute it as an example game for my own game engine. http://game-engine-for-java.googlecode.com/ But the problem here is that I can't get the bouncing condition working properly. Here's what I'm using. public void collision(GObject other){ if (other instanceof Bat || other instanceof Block){ bounce(); } else if (other instanceof Stone){ other.destroy(); bounce(); } //Breakout.HIT.play(); } And here's by bounce() method public void bounce(){ boolean left = false; boolean right = false; boolean up = false; boolean down = false; if (dx < 0) { left = true; } else if (dx > 0) { right = true; } if (dy < 0) { up = true; } else if (dy > 0) { down = true; } if (left && up) { dx = -dx; } if (left && down) { dy = -dy; } if (right && up) { dx = -dx; } if (right && down) { dy = -dy; } } The ball bounces the bat and blocks but when the block is on top of the ball, it won't bounce and moves upwards out of the game. What I'm missing? Is there anything to implement? Please help me.. Thanks

  Read the article

• Kinect Hand tracking in xna

  - by N0xus

  I'm trying to create an application using the Kinect to simulate the following project: Kinect Hand Tracking I want my project to have similar usability with the Kinect tracking hand and finger positions for use in a menu system, or to navigate another system. What I would like to know is; is it possible for the exact same to be accomplished in XNA using Kinect? I know that it can be done in Winform / C#, but I know XNA / C# a lot better and would (ideally) prefer to use that.

  Read the article

• Why do we use Pythagoras in game physics?

  - by Starkers

  I've recently learned that we use Pythagoras a lot in our physics calculations and I'm afraid I don't really get the point. Here's an example from a book to make sure an object doesn't travel faster than a MAXIMUM_VELOCITY constant in the horizontal plane: MAXIMUM_VELOCITY = <any number>; SQUARED_MAXIMUM_VELOCITY = MAXIMUM_VELOCITY * MAXIMUM_VELOCITY; function animate(){ var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; x_velocity = x_velocity / scalar; z_velocity = x_velocity / scalar; } } Let's try this with some numbers: An object is attempting to move 5 units in x and 5 units in z. It should only be able to move 5 units horizontally in total! MAXIMUM_VELOCITY = 5; SQUARED_MAXIMUM_VELOCITY = 5 * 5; SQUARED_MAXIMUM_VELOCITY = 25; function animate(){ var x_velocity = 5; var z_velocity = 5; var squared_horizontal_velocity = (x_velocity * x_velocity) + (z_velocity * z_velocity); var squared_horizontal_velocity = 5 * 5 + 5 * 5; var squared_horizontal_velocity = 25 + 25; var squared_horizontal_velocity = 50; // if( squared_horizontal_velocity <= SQUARED_MAXIMUM_VELOCITY ){ if( 50 <= 25 ){ scalar = squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY; scalar = 50 / 25; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Now this works well, but we can do the same thing without Pythagoras: MAXIMUM_VELOCITY = 5; function animate(){ var x_velocity = 5; var z_velocity = 5; var horizontal_velocity = x_velocity + z_velocity; var horizontal_velocity = 5 + 5; var horizontal_velocity = 10; // if( horizontal_velocity >= MAXIMUM_VELOCITY ){ if( 10 >= 5 ){ scalar = horizontal_velocity / MAXIMUM_VELOCITY; scalar = 10 / 5; scalar = 2.0; x_velocity = x_velocity / scalar; x_velocity = 5 / 2.0; x_velocity = 2.5; z_velocity = z_velocity / scalar; z_velocity = 5 / 2.0; z_velocity = 2.5; // new_horizontal_velocity = x_velocity + z_velocity // new_horizontal_velocity = 2.5 + 2.5 // new_horizontal_velocity = 5 } } Benefits of doing it without Pythagoras: Less lines Within those lines, it's easier to read what's going on ...and it takes less time to compute, as there are less multiplications Seems to me like computers and humans get a better deal without Pythagoras! However, I'm sure I'm wrong as I've seen Pythagoras' theorem in a number of reputable places, so I'd like someone to explain me the benefit of using Pythagoras to a maths newbie. Does this have anything to do with unit vectors? To me a unit vector is when we normalize a vector and turn it into a fraction. We do this by dividing the vector by a larger constant. I'm not sure what constant it is. The total size of the graph? Anyway, because it's a fraction, I take it, a unit vector is basically a graph that can fit inside a 3D grid with the x-axis running from -1 to 1, z-axis running from -1 to 1, and the y-axis running from -1 to 1. That's literally everything I know about unit vectors... not much :P And I fail to see their usefulness. Also, we're not really creating a unit vector in the above examples. Should I be determining the scalar like this: // a mathematical work-around of my own invention. There may be a cleverer way to do this! I've also made up my own terms such as 'divisive_scalar' so don't bother googling var divisive_scalar = (squared_horizontal_velocity / SQUARED_MAXIMUM_VELOCITY); var divisive_scalar = ( 50 / 25 ); var divisive_scalar = 2; var multiplicative_scalar = (divisive_scalar / (2*divisive_scalar)); var multiplicative_scalar = (2 / (2*2)); var multiplicative_scalar = (2 / 4); var multiplicative_scalar = 0.5; x_velocity = x_velocity * multiplicative_scalar x_velocity = 5 * 0.5 x_velocity = 2.5 Again, I can't see why this is better, but it's more "unit-vector-y" because the multiplicative_scalar is a unit_vector? As you can see, I use words such as "unit-vector-y" so I'm really not a maths whiz! Also aware that unit vectors might have nothing to do with Pythagoras so ignore all of this if I'm barking up the wrong tree. I'm a very visual person (3D modeller and concept artist by trade!) and I find diagrams and graphs really, really helpful so as many as humanely possible please!

  Read the article

• Which Open Source Licenses can address concerns for an Open Source Game Engine?

  - by Chris

  I am on a team that is looking to open source an engine we are building. It's intended as an engine for Online RPG style games. We're writing it to work on both desktops and android platforms. I've been over to the OSI http://opensource.org/licenses/category to check out the most common licenses. However, this will be my first time going into an open source project and I wanted to know if the community had some insight into which licenses might be best suited. Key licensing concerns: Removing or limiting our liability (most already seem to cover this, but stating for completeness). We want other developers to be able to take part or all of our project and use it in their own projects with proper accreditation to our project. Licensing should not hinder someone's ability to quickly use the engine. They should be able to download a release and start using it without needing to wait on licensing issues. Game content (gfx, sound, etc.) that is not part of the engine should be allowed to be licensed separately. If someone is using our engine, they can retain full copy right of their content, including engine generated data. Our primary goal is exposure, which is why we're going open source to start with. Both for the project and for the individuals developing it. Are there any licenses that can require accreditation visible to players? While I'd put our primary goal as exposure, for licensing the accreditation is less of a concern. From what I've read through (and have been able to understand) it doesn't seem like any of the licenses cover anything that is produced by the licensed software. Are there any that state this specifically, or does simply not mentioning it leave it open for other licensing? Are there any other concerns that we should consider? Has anyone had any issues using any of these licenses?

  Read the article

• Is using the student version of 3DS Max and Unity3d legal?

  - by SubZeron

  I am developing an indie game together with my friend using Unity3D engine. I bought "Silo 3D" for modeling two month ago and for texturing I use 3D coat. We plan to sell our game in the future. For the animations I work with 3DS max (only animation part). My question is, can I work with a students license? The license for the original version is too expensive for me. I am still at the university and I can not buy the 3DS Max license which costs 4000 €. As an alternative I have the choice beetween Blender (can´t work with this software and don't have time to invest for learning a new program) and Truespace (can´t export fbx animation and specially with bones) so for me, 3DS Max is the best choice to be effective and quick. Is it possible to prove it when I export my fbx characters from 3DS Max to Unity3D? I mean can they find out that I have used the students license of 3DS Max for the animations after the release of the game? Maybe with help of DRM? Can I solve that problem when I export the fbx from 3DS Max to Blender and after that export the same fbx to Unity3D?

  Read the article

• How to use the float value from Noise function in voxel terrain?

  - by therealjohn

  Im using Unity, although this question is not really specific to that engine. Im also using an asset from the store called Coherent Noise. It has some neat noise functionality built it. I am using those functions to produce some noise values. I am getting a value between 0 and 1 (floats). I have an array of blocks (for minecraft like voxel terrain) and I am confused on how to use this float value for terrain? Do I do something like <= 0 == Solid block etc etc? I am confused on how to use the floating values that the noise functions produce to use for height values of an array of say a height of 16. Thanks for any guidance.

  Read the article

• Particle and Physics problem.

  - by Quincy

  This was originally a forum post so I hope you guys don't mind it being 2 questions in one. I am making a game and I got some basic physics implemented. I have 2 problems, 1 with particles being drawn in the wrong place and one with going through walls while jumping in corners. Skip over to about 15 sec video showing the 2 problems : http://youtube.com/watch?v=Tm9nfWsWfiM So the problem with the particles seems to be coming from the removal, as soon as I remove that piece of code it instantly works, but there shouldn't be a problem since they shouldn't even draw when their energy gets to 0 (and then they get removed) So my first question is, how are these particles getting warped all over the screen ? Relevant code : Particle class : class Particle { //Physics public Vector2 position = new Vector2(0,0); public float direction = 180; public float speed = 100; public float energy = 1; protected float startEnergy = 1; //Visual public Sprite sprite; public float rotation = 0; public float scale = 1; public byte alpha = 255; public BlendMode blendMode { get { return sprite.BlendMode; } set { sprite.BlendMode = value; } } public Particle() { } public virtual void Think(float frameTime) { if (energy - frameTime < 0) energy = 0; else energy -= frameTime; position += new Vector2((float)Math.Cos(MathHelper.DegToRad(direction)), (float)Math.Sin(MathHelper.DegToRad(direction))) * speed * frameTime; alpha = (byte)(255 * energy / startEnergy); sprite.Rotation = rotation; sprite.Position = position; sprite.Color = new Color(sprite.Color.R, sprite.Color.G, sprite.Color.B, alpha); } public virtual void Draw(float frameTime) { if (energy > 0) { World.camera.DrawSprite(sprite); } } // Basic particle implementation class BasicSprite : Particle { public BasicSprite(Sprite _sprite) { sprite = _sprite; } } Emitter : class Emitter { protected static Random rand = new Random(); protected List<Particle> particles = new List<Particle>(); public BaseEntity target = null; public Vector2 position = new Vector2(0, 0); public bool Active = true; public float timeAlive = 0; public int particleCount = 0; public int ParticlesPerSeccond { get { return (int)(1 / particleSpawnTime); } set { particleSpawnTime = 1 / (float)value; } } public float dieTime = float.MaxValue; float particleSpawnTime = 0.05f; float spawnTime = 0; public Emitter() { } public virtual void Think(float frametime) { spawnTime += frametime; if (dieTime != float.MaxValue) { timeAlive += frametime; if (timeAlive >= dieTime) Active = false; } if (Active) { if (target != null) position = target.Position; while (spawnTime > particleSpawnTime) { spawnTime -= particleSpawnTime; AddParticle(); particleCount++; } } for (int i = 0; i < particles.Count; i++) { particles[i].Think(frametime); if (particles[i].energy <= 0) { particles.Remove(particles[i]); // As soon as this is removed, it works particleCount--; } } } public virtual void AddParticle() { } public virtual void Draw(float frametime) { foreach (Particle particle in particles) { particle.Draw(frametime); } } } class BloodEmitter : Emitter { Image image; public BloodEmitter() { image = new Image(@"Content/Particles/TinyCircle.png"); image.CreateMaskFromColor(new Color(255, 0, 255, 255)); this.dieTime = 0.5f; this.ParticlesPerSeccond = 100; } public override void AddParticle() { Sprite sprite = new Sprite(image); sprite.Color = new Color((byte)(rand.NextDouble() * 255), (byte)(rand.NextDouble() * 255), (byte)(rand.NextDouble() * 255)); BasicSprite particle = new BasicSprite(sprite); particle.direction = (float)rand.NextDouble() * 360; particle.position = position; particle.blendMode = BlendMode.Alpha; particles.Add(particle); } } The seccond problem is the physics problem, for some reason I can get through the right bottom corner while jumping. I think this is coming from me switching animations but I thought I made it compensate for that. Relevant code : PhysicsEntity : class PhysicsEntity : BaseEntity { // Horizontal movement constants protected const float maxHorizontalSpeed = 1000; protected const float horizontalAcceleration = 15; protected const float horizontalDragAir = 0.95f; protected const float horizontalDragGround = 0.95f; // Vertical movement constants protected const float maxVerticalSpeed = 1000; protected const float verticalAcceleration = 20; // Everything needed for movement and correct animations protected float movement = 0; protected bool onGround = false; protected Vector2 Velocity = new Vector2(0, 0); protected float maxSpeed = 0; float lastThink = 0; float thinkTime = 1f/60f; public PhysicsEntity(Vector2 position, Sprite sprite) : base(position, sprite) { } public override void Draw(float frameTime) { base.Draw(frameTime); } public override void Think(float frameTime) { CalculateMovement(frameTime); base.Think(frameTime); } protected void CalculateMovement(float frameTime) { lastThink += frameTime; while (lastThink > thinkTime) { onGround = false; Velocity.X = MathHelper.Clamp(Velocity.X + horizontalAcceleration * movement, -maxHorizontalSpeed, maxHorizontalSpeed); if (onGround) Velocity.X *= horizontalDragGround; else Velocity.X *= horizontalDragAir; if (maxSpeed < Velocity.X) maxSpeed = Velocity.X; Velocity.Y = MathHelper.Clamp(Velocity.Y + verticalAcceleration, -maxVerticalSpeed, maxVerticalSpeed); lastThink -= thinkTime; DoCollisions(thinkTime); DoAnimations(thinkTime); } } public virtual void DoAnimations(float frameTime) { } public void DoCollisions(float frameTime) { Position.Y += Velocity.Y * frameTime; Vector2 tileCollision = GetTileCollision(); if (tileCollision.X != -1 || tileCollision.Y != -1) { Vector2 collisionDepth = CollisionRectangle.DepthIntersection( new Rectangle( tileCollision.X * World.tileEngine.TileWidth, tileCollision.Y * World.tileEngine.TileHeight, World.tileEngine.TileWidth, World.tileEngine.TileHeight ) ); Position.Y += collisionDepth.Y; if (collisionDepth.Y < 0) onGround = true; Velocity.Y = 0; } Position.X += Velocity.X * frameTime; tileCollision = GetTileCollision(); if (tileCollision.X != -1 || tileCollision.Y != -1) { Vector2 collisionDepth = CollisionRectangle.DepthIntersection( new Rectangle( tileCollision.X * World.tileEngine.TileWidth, tileCollision.Y * World.tileEngine.TileHeight, World.tileEngine.TileWidth, World.tileEngine.TileHeight ) ); Position.X += collisionDepth.X; Velocity.X = 0; } } public void DoCollisions(Vector2 difference) { CollisionRectangle.Y = Position.Y - difference.Y; CollisionRectangle.Height += difference.Y; Vector2 tileCollision = GetTileCollision(); if (tileCollision.X != -1 || tileCollision.Y != -1) { Vector2 collisionDepth = CollisionRectangle.DepthIntersection( new Rectangle( tileCollision.X * World.tileEngine.TileWidth, tileCollision.Y * World.tileEngine.TileHeight, World.tileEngine.TileWidth, World.tileEngine.TileHeight ) ); Position.Y += collisionDepth.Y; if (collisionDepth.Y < 0) onGround = true; Velocity.Y = 0; } CollisionRectangle.X = Position.X - difference.X; CollisionRectangle.Width += difference.X; tileCollision = GetTileCollision(); if (tileCollision.X != -1 || tileCollision.Y != -1) { Vector2 collisionDepth = CollisionRectangle.DepthIntersection( new Rectangle( tileCollision.X * World.tileEngine.TileWidth, tileCollision.Y * World.tileEngine.TileHeight, World.tileEngine.TileWidth, World.tileEngine.TileHeight ) ); Position.X += collisionDepth.X; Velocity.X = 0; } } Vector2 GetTileCollision() { int topLeftTileX = (int)(CollisionRectangle.TopLeft.X / World.tileEngine.TileWidth); int topLeftTileY = (int)(CollisionRectangle.TopLeft.Y / World.tileEngine.TileHeight); int BottomRightTileX = (int)(CollisionRectangle.DownRight.X / World.tileEngine.TileWidth); int BottomRightTileY = (int)(CollisionRectangle.DownRight.Y / World.tileEngine.TileHeight); if (CollisionRectangle.DownRight.Y % World.tileEngine.TileHeight == 0) // If your exactly against the tile don't count that as being inside the tile BottomRightTileY -= 1; if (CollisionRectangle.DownRight.X % World.tileEngine.TileWidth == 0) // If your exactly against the tile don't count that as being inside the tile BottomRightTileX -= 1; for (int i = topLeftTileX; i <= BottomRightTileX; i++) { for (int j = topLeftTileY; j <= BottomRightTileY; j++) { if (World.tileEngine.TileIsSolid(i, j)) { return new Vector2(i, j); } } } return new Vector2(-1, -1); } } Player : enum State { Standing, Running, Jumping, Falling, Sliding, WallSlide } class Player : PhysicsEntity { private State state { get { return currentState; } set { if (currentState != value) { currentState = value; animationChanged = true; } } } private State currentState = State.Standing; private BasicEmitter basicEmitter = new BasicEmitter(); public bool flipped; public bool animationChanged = false; protected const float jumpPower = 600; AnimationManager animationManager; Rectangle DrawRectangle; public override Rectangle CollisionRectangle { get { return new Rectangle( Position.X - DrawRectangle.Width / 2f, Position.Y - DrawRectangle.Height / 2f, DrawRectangle.Width, DrawRectangle.Height ); } } public Player(Vector2 position, Sprite sprite) : base(position, sprite) { // Only posted the relevant bit DrawRectangle = animationManager.currentAnimation.drawingRectangle; } public override void Draw(float frameTime) { World.camera.DrawSprite( Sprite, Position + new Vector2(DrawRectangle.X, DrawRectangle.Y), animationManager.currentAnimation.drawingRectangle ); } public override void Think(float frameTime) { //I only posted the relevant stuff if (animationChanged) { // if the animation has changed make sure we compensate for the change in with and height animationChanged = false; DoCollisions(animationManager.getSizeDifference()); } DoCustomMovement(); base.Think(frameTime); if (!onGround && Velocity.Y > 0) { state = State.Falling; } } void DoCustomMovement() { if (onGround) { if (World.renderWindow.Input.IsKeyDown(KeyCode.W)) { Velocity.Y = -jumpPower; state = State.Jumping; } } } public override void DoAnimations(float frameTime) { string stateName = Enum.GetName(typeof(State), state); if (!animationManager.currentAnimationIs(stateName)) { animationManager.PlayAnimation(stateName); } animationManager.Think(frameTime); DrawRectangle = animationManager.currentAnimation.drawingRectangle; Sprite.Center = new Vector2( DrawRectangle.X + DrawRectangle.Width / 2, DrawRectangle.Y + DrawRectangle.Height / 2 ); Sprite.FlipX(flipped); } So why am I warping through walls ? I have given this some thought but I just can't seem to find out why this is happening. Full source if needed : source : http://www.mediafire.com/?rc7ddo09gnr68zd (download link)

  Read the article

• Is it safe StringToHash() to use in Unity?

  - by Sebastian Krysmanski

  I'm currently browsing through the Unity tutorials and saw that they're recommending to use Animator.StringToHash("some string") to created unique ids for animation properties (see here). Since I'm a programmer, to me the word "hash" doesn't represents something unique. Like the Java documentation for hashValue() states: It is not required that if two objects are unequal [...], then calling the hashCode method on each of the two objects must produce distinct integer results. So, according to this (and my definition of "hash"), two strings may have the same hash value. (You can also argue that there are an infinite number of possible strings but only 2^32 possible int values.) So, is there a possibility that StringToHash() will give me an id that actually belongs to another property (than the one I requested the hash for)?

  Read the article

< Previous Page | 575 576 577 578 579 580 581 582 583 584 585 586  | Next Page >