Search Results

Search found 26124 results on 1045 pages for 'unreal development kit'.

Page 462/1045 | < Previous Page | 458 459 460 461 462 463 464 465 466 467 468 469  | Next Page >

  • How can I achieve strong typing with a component messaging system?

    - by Vaughan Hilts
    I'm looking at implementing a messaging system in my entity component system. I've deduced that I can use an event / queue for passing messages, but right now, I just use a generic object and cast out the data I want. I also considered using a dictionary. I see a lot of information on this, but they all involve a lot of casting and guessing. Is there any way to do this elegantly and keep strong typing on my messages?

    Read the article

  • Smooth waypoint traversing

    - by TheBroodian
    There are a dozen ways I could word this question, but to keep my thoughts in line, I'm phrasing it in line with my problem at hand. So I'm creating a floating platform that I would like to be able to simply travel from one designated point to another, and then return back to the first, and just pass between the two in a straight line. However, just to make it a little more interesting, I want to add a few rules to the platform. I'm coding it to travel multiples of whole tile values of world data. So if the platform is not stationary, then it will travel at least one whole tile width or tile height. Within one tile length, I would like it to accelerate from a stop to a given max speed. Upon reaching one tile length's distance, I would like it to slow to a stop at given tile coordinate and then repeat the process in reverse. The first two parts aren't too difficult, essentially I'm having trouble with the third part. I would like the platform to stop exactly at a tile coordinate, but being as I'm working with acceleration, it would seem easy to simply begin applying acceleration in the opposite direction to a value storing the platform's current speed once it reaches one tile's length of distance (assuming that the tile is traveling more than one tile-length, but to keep things simple, let's just assume it is)- but then the question is what would the correct value be for acceleration to increment from to produce this effect? How would I find that value?

    Read the article

  • How can I show a texture in a separate window in an XNA game?

    - by John
    I'm playing around with random map generation and what I want to do is: Input a command to generate a random map. A texture will be created resembling the generation, each pixel resembling each tile. A new window will pop-up, without removing the original one, that will contain the texture. I know how to do this except for the last part. Would someone please tell me how to create a new window and draw a texture to this window?

    Read the article

  • Orthographic Projection with variable FOV

    - by cubrman
    We are building agame with orthographic view. The problem we face is the fact that with different resolution you can see different area of the game world. E.g. if you have higher resolution you can see more around you. To solve this we currently use a common scale factor that every model is scaled by, depending on resolution. But this has drawbacks when drawing shadows - I cannot set a higher view angle for the orthographic shadow camera, while when using the perspective shadow camera I get significantly worse shadow quality. So the question is is there any way to controll FOV when using orthographic projection, or, more specifically, what is the easiest way to scale the world uniformly up or down with orthographic projection matrix? I saw that in 3ds MAX you can control FOV for an orthographic camera I wonder how they implemented it.

    Read the article

  • How to implement explosion in OpenGL?

    - by Chan
    I'm relatively new to OpenGL and I'm clueless how to implement explosion. So could anyone give me some ideas how to start? Suppose the explosion occurs at location $(x, y, z)$, then I'm thinking of randomly generate a collection of vectors with $(x, y, z)$ as origin, then draw some particle (glutSolidCube) which move along this vector for some period of time, says after 1000 updates, it disappear. Is this approach feasible? A minimal example would be greatly appreciated.

    Read the article

  • Game ideas for a platformer

    - by user5925
    I have created a platformer which currently has the features listed below. I would greatly appreciate any further ideas which I could implement! (I don't play a lot of games which is why I require help) -- Walking/jumping/movement -- player can shoot lasers -- enemies also walk, fly, and shoot lasers -- water (you can swim in this) -- mud (slows you down on contact, and stops you from jumping) -- ladders -- damage when falling from a large height, unless falling into water -- moving platforms -- springboards (jumping on them shoot you into the air) -- growing platforms (allow you to reach new places) -- key and door system -- gem and coin collection system

    Read the article

  • Optimal Compression for Speech

    - by ashes999
    I'm designing a game that depends heavily on audio; I will have some 300+ speech files (most of them just a word or two long). This can very quickly escalate the size of my final game. What's the optimal way to encode/compress speech files to keep the size minimal without getting audio artifacts? Please address both per-file compression/encoding, and also zipping/compressing the set of all speech files together in your answer. Because I'm not sure which (or combination of both) factors will give me the best results. Edit: I need this to run in Silverlight and Android, so I'm presumably stuck with only MP3 as my option (other than uncompressed wave files).

    Read the article

  • Normal map lighting bug in bottom right quadrant

    - by Ryan Capote
    I am currently working on getting normal maps working in my project, and have run into a problem with lighting. As you can see, the normals in the bottom right quadrant of the lighting isn't calculating the correct direction to the light or something. Best seen by the red light If I use flat normals (z normal = 1.0), it seems to be working fine: normals for the tile sheet: Shader: #version 330 uniform sampler2D uDiffuseTexture; uniform sampler2D uNormalsTexture; uniform sampler2D uSpecularTexture; uniform sampler2D uEmissiveTexture; uniform sampler2D uWorldNormals; uniform sampler2D uShadowMap; uniform vec4 uLightColor; uniform float uConstAtten; uniform float uLinearAtten; uniform float uQuadradicAtten; uniform float uColorIntensity; in vec2 TexCoords; in vec2 GeomSize; out vec4 FragColor; float sample(vec2 coord, float r) { return step(r, texture2D(uShadowMap, coord).r); } float occluded() { float PI = 3.14; vec2 normalized = TexCoords.st * 2.0 - 1.0; float theta = atan(normalized.y, normalized.x); float r = length(normalized); float coord = (theta + PI) / (2.0 * PI); vec2 tc = vec2(coord, 0.0); float center = sample(tc, r); float sum = 0.0; float blur = (1.0 / GeomSize.x) * smoothstep(0.0, 1.0, r); sum += sample(vec2(tc.x - 4.0*blur, tc.y), r) * 0.05; sum += sample(vec2(tc.x - 3.0*blur, tc.y), r) * 0.09; sum += sample(vec2(tc.x - 2.0*blur, tc.y), r) * 0.12; sum += sample(vec2(tc.x - 1.0*blur, tc.y), r) * 0.15; sum += center * 0.16; sum += sample(vec2(tc.x + 1.0*blur, tc.y), r) * 0.15; sum += sample(vec2(tc.x + 2.0*blur, tc.y), r) * 0.12; sum += sample(vec2(tc.x + 3.0*blur, tc.y), r) * 0.09; sum += sample(vec2(tc.x + 4.0*blur, tc.y), r) * 0.05; return sum * smoothstep(1.0, 0.0, r); } float calcAttenuation(float distance) { float linearAtten = uLinearAtten * distance; float quadAtten = uQuadradicAtten * distance * distance; float attenuation = 1.0 / (uConstAtten + linearAtten + quadAtten); return attenuation; } vec3 calcFragPosition(void) { return vec3(TexCoords*GeomSize, 0.0); } vec3 calcLightPosition(void) { return vec3(GeomSize/2.0, 0.0); } float calcDistance(vec3 fragPos, vec3 lightPos) { return length(fragPos - lightPos); } vec3 calcLightDirection(vec3 fragPos, vec3 lightPos) { return normalize(lightPos - fragPos); } vec4 calcFinalLight(vec2 worldUV, vec3 lightDir, float attenuation) { float diffuseFactor = dot(normalize(texture2D(uNormalsTexture, worldUV).rgb), lightDir); vec4 diffuse = vec4(0.0); vec4 lightColor = uLightColor * uColorIntensity; if(diffuseFactor > 0.0) { diffuse = vec4(texture2D(uDiffuseTexture, worldUV.xy).rgb, 1.0); diffuse *= diffuseFactor; lightColor *= diffuseFactor; } else { discard; } vec4 final = (diffuse + lightColor); if(texture2D(uWorldNormals, worldUV).g > 0.0) { return final * attenuation; } else { return final * occluded(); } } void main(void) { vec3 fragPosition = calcFragPosition(); vec3 lightPosition = calcLightPosition(); float distance = calcDistance(fragPosition, lightPosition); float attenuation = calcAttenuation(distance); vec2 worldPos = gl_FragCoord.xy / vec2(1024, 768); vec3 lightDir = calcLightDirection(fragPosition, lightPosition); lightDir = (lightDir*0.5)+0.5; float atten = calcAttenuation(distance); vec4 emissive = texture2D(uEmissiveTexture, worldPos); FragColor = calcFinalLight(worldPos, lightDir, atten) + emissive; }

    Read the article

  • Box2d world width and height ratio with screen width and height

    - by Sujith
    I have view, for example GameView which extends SurfaceView . I have integrated Box2D physics in GameView. I have two widths , GameView width, height and Box2D physics world width ,height. I need to get the position of box2d world with the GameView co-ordinates. For example, Total width of screen = 240 Total height of screen = 320 Screen points needed to be mapped onto box2d co-ordinates (x,y) = 127, 139 For this i need to get the max width and height of the Box2d physics world. Is there is any way to get the max width and height of Box2d world. or Can i limit the width and height of box2d world within the screen resolution.

    Read the article

  • Quake 3 Bot Programming Example

    - by Manni
    I would like to implement an intelligent bot for Quake-3. I downloaded the and built the code successfully under Linux. My problem is that I couldn't find any complete tutorial telling me how to build an agent; telling which files to use( as there are many files in the source code). Can you give me a website or piece of source code telling me how to start? Or something like an example source code for a bot.

    Read the article

  • Unity iOS optimization and draw calls

    - by vzm
    I am curious of what methods I should approach in optimizing my Unity project for iOS hardware. I have very little image effects running (directional light with low res shadows) and I used the combine children script from the standard assets to lessen the load on the CPU. My project currently runs with 45-57 draw calls at non-intensive segments and up to 178 at intensive segments. I heard that static batching relieves some of the stress, but the game has the environment moving around the player instead of the player moving around the environment. Is there any alternative that I may look towards to improving the draw call number?

    Read the article

  • PHP Battle System for RPG game

    - by Jay
    I posted this a while ago on stackoverflow, they thought it would be better place here, I agree. Essentially I know what I want to accomplish, and I have something to the effect of what I want but I am not satisfied with it. Here's the problem. Each user has some states: STR (how hard they hit), DEF (dodging/blocking attacks), SPD (when they can strike), and STAMINA (basically their endurance in game, if this runs out they can no longer fight and lose) What I need is something like this: UserA Stats: STR: 1,000 DEF: 2500 SPD: 2000 (HP: 1000/1000) UserB Stats: STR: 1,500 DEF: 500 SPD: 4000 (HP: 1000/1000) Because the second user has double the speed, he lands twice the amount of hits on the first user, before he gets hit. Because he has less strength than the first users defence, he will do no, to little damage. This is how the battle would theoretically go: UserB strikes UserA for 0 damage UserB strikes UserA for 0 damage UserA strikes UserB for 500 damage UserB strikes UserA for 0 damage UserB strikes UserA for 0 damage UserA strikes UserB for 500 damage, and sends him to the hospital! I was using this code, which is buggy, and not efficient, I just need a better way to do this: http://pastebin.com/15LiQQuJ Oh, and if anyone has some good ideas on how to improve the concept that would be cool too! It's not that elaborate so I'll be thinking of all sorts of things to make it more dynamic. Thanks.

    Read the article

  • LWJGL - Mixing 2D and 3D

    - by nathan
    I'm trying to mix 2D and 3D using LWJGL. I have wrote 2D little method that allow me to easily switch between 2D and 3D. protected static void make2D() { glEnable(GL_BLEND); GL11.glMatrixMode(GL11.GL_PROJECTION); GL11.glLoadIdentity(); glOrtho(0.0f, SCREEN_WIDTH, SCREEN_HEIGHT, 0.0f, 0.0f, 1.0f); GL11.glMatrixMode(GL11.GL_MODELVIEW); GL11.glLoadIdentity(); } protected static void make3D() { glDisable(GL_BLEND); GL11.glMatrixMode(GL11.GL_PROJECTION); GL11.glLoadIdentity(); // Reset The Projection Matrix GLU.gluPerspective(45.0f, ((float) SCREEN_WIDTH / (float) SCREEN_HEIGHT), 0.1f, 100.0f); // Calculate The Aspect Ratio Of The Window GL11.glMatrixMode(GL11.GL_MODELVIEW); glLoadIdentity(); } The in my rendering code i would do something like: make2D(); //draw 2D stuffs here make3D(); //draw 3D stuffs here What i'm trying to do is to draw a 3D shape (in my case a quad) and i 2D image. I found this example and i took the code from TextureLoader, Texture and Sprite to load and render a 2D image. Here is how i load the image. TextureLoader loader = new TextureLoader(); Sprite s = new Sprite(loader, "player.png") And how i render it: make2D(); s.draw(0, 0); It works great. Here is how i render my quad: glTranslatef(0.0f, 0.0f, 30.0f); glScalef(12.0f, 9.0f, 1.0f); DrawUtils.drawQuad(); Once again, no problem, the quad is properly rendered. DrawUtils is a simple class i wrote containing utility method to draw primitives shapes. Now my problem is when i want to mix both of the above, loading/rendering the 2D image, rendering the quad. When i try to load my 2D image with the following: s = new Sprite(loader, "player.png); My quad is not rendered anymore (i'm not even trying to render the 2D image at this point). Only the fact of creating the texture create the issue. After looking a bit at the code of Sprite and TextureLoader i found that the problem appears after the call of the glTexImage2d. In the TextureLoader class: glTexImage2D(target, 0, dstPixelFormat, get2Fold(bufferedImage.getWidth()), get2Fold(bufferedImage.getHeight()), 0, srcPixelFormat, GL_UNSIGNED_BYTE, textureBuffer); Commenting this like make the problem disappear. My question is then why? Is there anything special to do after calling this function to do 3D? Does this function alter the render part, the projection matrix?

    Read the article

  • GUI for DirectX

    - by DeadMG
    I'm looking for a GUI library built on top of DirectX- preferably 9, but I can also do 11. I've looked at stuff like DXUT, but it's way too much for me- I'm only needing some UI controls which I would rather not write (and debug) myself, and their need to keep a C-compatible API is definitely a big downside. I'd rather look at UI libs that are designed to be integrated into an existing DirectX-based system, rather than forming the basis of a system. Any recommendations?

    Read the article

  • Ray Intersecting Plane Formula in C++/DirectX

    - by user4585
    I'm developing a picking system that will use rays that intersect volumes and I'm having trouble with ray intersection versus a plane. I was able to figure out spheres fairly easily, but planes are giving me trouble. I've tried to understand various sources and get hung up on some of the variables used within their explanations. Here is a snippet of my code: bool Picking() { D3DXVECTOR3 vec; D3DXVECTOR3 vRayDir; D3DXVECTOR3 vRayOrig; D3DXVECTOR3 vROO, vROD; // vect ray obj orig, vec ray obj dir D3DXMATRIX m; D3DXMATRIX mInverse; D3DXMATRIX worldMat; // Obtain project matrix D3DXMATRIX pMatProj = CDirectXRenderer::GetInstance()->Director()->Proj(); // Obtain mouse position D3DXVECTOR3 pos = CGUIManager::GetInstance()->GUIObjectList.front().pos; // Get window width & height float w = CDirectXRenderer::GetInstance()->GetWidth(); float h = CDirectXRenderer::GetInstance()->GetHeight(); // Transform vector from screen to 3D space vec.x = (((2.0f * pos.x) / w) - 1.0f) / pMatProj._11; vec.y = -(((2.0f * pos.y) / h) - 1.0f) / pMatProj._22; vec.z = 1.0f; // Create a view inverse matrix D3DXMatrixInverse(&m, NULL, &CDirectXRenderer::GetInstance()->Director()->View()); // Determine our ray's direction vRayDir.x = vec.x * m._11 + vec.y * m._21 + vec.z * m._31; vRayDir.y = vec.x * m._12 + vec.y * m._22 + vec.z * m._32; vRayDir.z = vec.x * m._13 + vec.y * m._23 + vec.z * m._33; // Determine our ray's origin vRayOrig.x = m._41; vRayOrig.y = m._42; vRayOrig.z = m._43; D3DXMatrixIdentity(&worldMat); //worldMat = aliveActors[0]->GetTrans(); D3DXMatrixInverse(&mInverse, NULL, &worldMat); D3DXVec3TransformCoord(&vROO, &vRayOrig, &mInverse); D3DXVec3TransformNormal(&vROD, &vRayDir, &mInverse); D3DXVec3Normalize(&vROD, &vROD); When using this code I'm able to detect a ray intersection via a sphere, but I have questions when determining an intersection via a plane. First off should I be using my vRayOrig & vRayDir variables for the plane intersection tests or should I be using the new vectors that are created for use in object space? When looking at a site like this for example: http://www.tar.hu/gamealgorithms/ch22lev1sec2.html I'm curious as to what D is in the equation AX + BY + CZ + D = 0 and how does it factor in to determining a plane intersection? Any help will be appreciated, thanks.

    Read the article

  • Java Applet Tower Defence Game needs tweeking

    - by Ephiras
    Hello :) i have made a tower defence Game for my computer science class as one of my major projects, but have encountered some rather fatal roadblocks. here they are creating a menu screen (class Menu) that can set the total number of enimies, the max number of towers, starting money and the map. i tried creating a constructor in my Main class that sets all the values to whatever the Menu class passes in. I want the Menu screen to close after a difficulty has been selected and the main class to begin. Another problem i would really like some help with is instead of having to write entire arrays i would like to create a small segment of code that runs through an entire picture and sets up an array based on that pixels color.this way i can have multiple levels just dragged into a level folder and have the program read through them. users can even create their own. so a 1 if its yellow, a two if blue and a 3 if purple, then everything else = 0; you can download all the classes and code uif you'd like here sorry about having to redirect you but i wasn't sure how to efficently add a code spoiler. help is greatly appreciated

    Read the article

  • Collision and Graphics integration

    - by Shlomi Atia
    I'm a little confused about the integration between collision and graphics. They both need to share the same position in the world. The most obvious choice is the center of the entity, which is good for bounding volumes and fixed sized sprites. However, for characters with variable height size sprites like this: http://gamemedia.wcgame.ru/data/2011-07-17/game-sprite-sheet.jpg This is no longer good. The character won't align to the ground if I'll draw it from the center. I can just make the sprites the same height, but it will be a waste of memory (the largest sprite is 4 times larger then the smallest one). Even then, this is not an option at all with skeletal sprites like this one: http://user-generated-content.java-gaming.org/img-vault/212a171fc1ebb27ab77608fb9b2dd9bd9205361ce6300b21a7f8d06d025fbbd8.png It seems that the graphics need to be drawn from the ground for characters, but not for other images such as scenery and obstacles. The only solution I could think of was having another position called draw-position, which is the entity center for images, and is the the bottom of the collision volume for characters. Then when I draw relative to that position, it should work properly. I haven't found any references for something like that, so I'm kinda insecure about it. Does anyone knows of a better approach for this problem? Thanks

    Read the article

  • How to add a sound that an enemy AI can hear?

    - by Chris
    Given: a 2D top down game Tiles are stored just in a 2D array Every tile has a property - dampen (so bricks might be -50db, air might be -1) From this I want to add it so a sound is generated at point x1, y1 and it "ripples out". The image below kind of outlines it better. Obviously the end goal is that the AI enemy can "hear" the sound - but if a wall is blocking it, the sound doesn't travel as far. Red is the wall, which has a dampen of 50db. I think in the 3rd game tick I am confusing my maths. What would be the best way of implementing this?

    Read the article

  • projected textures not appear on the "back" of the mesh as well?

    - by user975135
    I want to create blood wounds on my character's bodies by using projected textures. I've watched some commentaries on games like Left 4 Dead and they say they use projected textures for the blood. But the way projected textures work is that if you project a texture on a rigged character, say his chest, it will also appear on his back. So what's the trick? How to get projected textures appear only on one "side" of the mesh? I use the Panda3D game engine, if that will help.

    Read the article

  • Data structures for a 2D multi-layered and multi-region map?

    - by DevilWithin
    I am working on a 2D world editor and a world format subsequently. If I were to handle the game "world" being created just as a layered set of structures, either in top or side views, it would be considerably simple to do most things. But, since this editor is meant for 3rd parties, I have no clue how big worlds one will want to make and I need to keep in mind that eventually it will become simply too much to check, handling and comparing stuff that are happening completely away from the player position. I know the solution for this is to subdivide my world into sub regions and stream them on the fly, loading and unloading resources and other data. This way I know a virtually infinite game area is achievable. But, while I know theoretically what to do, I really have a few questions I'd hoped to get answered for some hints about the topic. The logic way to handle the regions is some kind of grid, would you pick evenly distributed blocks with equal sizes or would you let the user subdivide areas by taste with irregular sized rectangles? In case of even grids, would you use some kind of block/chunk neighbouring system to check when the player transposes the limit or just put all those in a simple array? Being a region a different data structure than its owner "game world", when streaming a region, would you deliver the objects to the parent structures and track them for unloading later, or retain the objects in each region for a more "hard-limit" approach? Introducing the subdivision approach to the project, and already having a multi layered scene graph structure on place, how would i make it support the new concept? Would you have the parent node have the layers as children, and replicate in each layer node, a node per region? Or the opposite, parent node owns all the regions possible, and each region has multiple layers as children? Or would you just put the region logic outside the graph completely(compatible with the first suggestion in Q.3) When I say virtually infinite worlds, I mean it of course under the contraints of the variable sizes and so on. Using float positions, a HUGE world can already be made. Do you think its sane to think beyond that? Because I think its ok to stick to this limit since it will never be reached so easily.. As for when to stream a region, I'm implementing it as a collection of watcher cameras, which the streaming system works with to know what to load/unload. The problem here is, i will be needing some kind of warps/teleports built in for my game, and there is a chance i will be teleporting a player to a unloaded region far away. How would you approach something like this? Is it sane to load any region to memory which can be teleported to by a warp within a radius from the player? Sorry for the huge question, any answers are helpful!

    Read the article

  • Object-Oriented OpenGL

    - by Sullivan
    I have been using OpenGL for a while and have read a large number of tutorials. Aside from the fact that a lot of them still use the fixed pipeline, they usually throw all the initialisation, state changes and drawing in one source file. This is fine for the limited scope of a tutorial, but I’m having a hard time working out how to scale it up to a full game. How do you split your usage of OpenGL across files? Conceptually, I can see the benefits of having, say, a rendering class that purely renders stuff to screen, but how would stuff like shaders and lights work? Should I have separate classes for things like lights and shaders?

    Read the article

  • Basics of drawing in 2d with OpenGL 3 shaders

    - by davidism
    I am new to OpenGL 3 and graphics programming, and want to create some basic 2d graphics. I have the following scenario of how I might go about drawing a basic (but general) 2d rectangle. I'm not sure if this is the correct way to think about it, or, if it is, how to implement it. In my head, here's how I imagine doing it: t = make_rectangle(width, height) build general VBO, centered at 0, 0 optionally: t.set_scale(2) optionally: t.set_angle(30) t.draw_at(x, y) calculates some sort of scale/rotate/translate matrix (or matrices), passes the VBO and the matrix to a shader program Something happens to clip the world to the view visible on screen. I'm really unclear on how 4 and 5 will work. The main problem is that all the tutorials I find either: use fixed function pipeline, are for 3d, or are unclear how to do something this "simple". Can someone provide me with either a better way to think of / do this, or some concrete code detailing performing the transformations in a shader and constructing and passing the data required for this shader transformation?

    Read the article

  • Unity3D - Android pause screen - double click issue

    - by user3666251
    I made a pause script for the game im developing for android. I added the script to the GUITexture I created and placed on the top right side of the screen.The issue stands at the part where if the player clicks the pause button then clicks resume then he wants to pause the game again.When he clicks pause the second time the buttons dont show up unless he clicks again. This is the script : #pragma strict var paused = false; var isButtonVisible : boolean = true; function OnMouseDown(){ this.paused = !this.paused; Time.timeScale = 0; isButtonVisible = true; } function OnGUI(){ if ( isButtonVisible ) { if(this.paused){ if (GUI.Button(Rect(Screen.width/2-100,Screen.height/2+3,200,50),"Restart")){ Application.LoadLevel(Application.loadedLevel); Time.timeScale = 1; isButtonVisible = false; } if (GUI.Button(Rect(Screen.width/2-100,Screen.height/2-50,200,50),"Resume")){ Time.timeScale = 1; isButtonVisible = false; } // Insert the rest of the pause menu logic if (GUI.Button(Rect(Screen.width/2-100,Screen.height/2+56,200,50),"Main Menu")){ Application.LoadLevel ("MainMenu"); isButtonVisible = false; Time.timeScale = 1; } } } } Thank you.

    Read the article

  • determine collision angle on a rotating body

    - by jorb
    update: new diagram and updated description I have a contact listener set up to try and determine the side that a collision happened at relative to the a bodies rotation. One way to solve this is to find the value of the yellow angle between the red and blue vectors drawn above. The angle can be found by taking the arc cosine of the dot product of the two vectors (Evan pointed this out). One of my points of confusion is the difference in domain of the atan2 function html canvas coordinates and the Box2d rotation information. I know I have to account for this somehow... SS below questions: Does Box2D provide these angles more directly in the collision information? Am I even on the right track? If so, any hints? I have the following javascript so far: Ship.prototype.onCollide = function (other_ent,cx,cy) { var pos = this.body.GetPosition(); //collision position relative to body var d_cx = pos.x - cx; var d_cy = pos.y - cy; //length of initial vector var len = Math.sqrt(Math.pow(pos.x -cx,2) + Math.pow(pos.y-cy,2)); //body angle - can over rotate hence mod 2*Pi var ang = this.body.GetAngle() % (Math.PI * 2); //vector representing body's angle - same magnitude as the first var b_vx = len * Math.cos(ang); var b_vy = len * Math.sin(ang); //dot product of the two vectors var dot_prod = d_cx * b_vx + d_cy * b_vy; //new calculation of difference in angle - NOT WORKING! var d_ang = Math.acos(dot_prod); var side; if (Math.abs(d_ang) < Math.PI/2 ) side = "front"; else side = "back"; console.log("length",len); console.log("pos:",pos.x,pos.y); console.log("offs:",d_cx,d_cy); console.log("body vec",b_vx,b_vy); console.log("body angle:",ang); console.log("dot product",dot_prod); console.log("result:",d_ang); console.log("side",side); console.log("------------------------"); }

    Read the article

  • CW/CCW Rotation of a Vector

    - by user23132
    Considering that I have a vector A, and after an arbitrary rotation I get vector B. I want to use this rotation operation in others vectors as well, but I'm having problems in doing that. My idea do that is to calculate the perpendicular vector C of the plane AB (by calculating AxB). This vector C is the axis that I'll need to rotate. To discover the angle I used the dot product between A and B, the acos of the dot product will return the lowest angle between A and B, the angle ang. The rotation I need to do is then: -rotate *ang*º around the C axis. The problem is that I dont know if this rotation is a CW or CCW rotation, since the cos of the dot product does not give me information of the sign of the angle. There's a tip discover that in 2D ( A.x * B.y - A.y * B.x) that you can use to discover if the vector A is at left/right of vector B. But I dont know how to do this in 3D space. Can anyone help me?

    Read the article

< Previous Page | 458 459 460 461 462 463 464 465 466 467 468 469  | Next Page >