Search Results

Search found 33291 results on 1332 pages for 'development environment'.

Page 457/1332 | < Previous Page | 453 454 455 456 457 458 459 460 461 462 463 464  | Next Page >

• 2D object-aligned bounding-box intersection test

  - by AshleysBrain

  Hi all, I have two object-aligned bounding boxes (i.e. not axis aligned, they rotate with the object). I'd like to know if two object-aligned boxes overlap. (Edit: note - I'm using an axis-aligned bounding box test to quickly discard distant objects, so it doesn't matter if the quad routine is a little slower.) My boxes are stored as four x,y points. I've searched around for answers, but I can't make sense of the variable names and algorithms in examples to apply them to my particular case. Can someone help show me how this would be done, in a clear and simple way? Thanks. (The particular language isn't important, C-style pseudo code is OK.)

  Read the article

• What's wrong with this turn to face algorithm?

  - by Chan

  I implement a torpedo object that chases a rotating planet. Specifically, it will turn toward the planet each update. Initially my implement was: void move() { vector3<float> to_target = target - get_position(); to_target.normalize(); position += (to_target * speed); } which works perfectly for torpedo that is a solid sphere. Now my torpedo is actually a model, which has a forward vector, so using this method looks odd because it doesn't actually turn toward but jump toward. So I revised it a bit to get, double get_rotation_angle(vector3<float> u, vector3<float> v) const { u.normalize(); v.normalize(); double cosine_theta = u.dot(v); // domain of arccosine is [-1, 1] if (cosine_theta > 1) { cosine_theta = 1; } if (cosine_theta < -1) { cosine_theta = -1; } return math3d::to_degree(acos(cosine_theta)); } vector3<float> get_rotation_axis(vector3<float> u, vector3<float> v) const { u.normalize(); v.normalize(); // fix linear case if (u == v || u == -v) { v[0] += 0.05; v[1] += 0.0; v[2] += 0.05; v.normalize(); } vector3<float> axis = u.cross(v); return axis.normal(); } void turn_to_face() { vector3<float> to_target = (target - position); vector3<float> axis = get_rotation_axis(get_forward(), to_target); double angle = get_rotation_angle(get_forward(), to_target); double distance = math3d::distance(position, target); gl_matrix_mode(GL_MODELVIEW); gl_push_matrix(); { gl_load_identity(); gl_translate_f(position.get_x(), position.get_y(), position.get_z()); gl_rotate_f(angle, axis.get_x(), axis.get_y(), axis.get_z()); gl_get_float_v(GL_MODELVIEW_MATRIX, OM); } gl_pop_matrix(); move(); } void move() { vector3<float> to_target = target - get_position(); to_target.normalize(); position += (get_forward() * speed); } The logic is simple, I find the rotation axis by cross product, the angle to rotate by dot product, then turn toward the target position each update. Unfortunately, it looks extremely odds since the rotation happens too fast that it always turns back and forth. The forward vector for torpedo is from the ModelView matrix, the third column A: MODELVIEW MATRIX -------------------------------------------------- R U A T -------------------------------------------------- 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 -------------------------------------------------- Any suggestion or idea would be greatly appreciated.

  Read the article

• Maximum number of controllers Unity3D can handle

  - by N0xus

  I've been trying to find out the maximum amount of xbox controller Unity3D can handle on one editor. I know through networking, Unity is capable of having as many people as your hardware can handle. But I want to avoid networking as much as possible. Thus, on a single computer, and in a single screen (think Bomberman and Super Smash Brothers) how many xbox controllers can Unity3D support? I have done work in XNA and remember that only being capable of support 4, but for the life of me, I can't find any information that tells me how many Unity can support.

  Read the article

• Odd Android touch event problem

  - by user22241

  Overview When testing my game I came across a bizarre problem with my touch controls. Note this isn't related to multi-touch as I completely removed my ACTION_POINTER_UP and ACTION_POINTER_DOWN along with my ACTION_MOVE code. So I'm simply working with ACTION_UP and ACTION_DOWN now and still get the problem. The problem I have a left and right button on the left of the screen and a jump button on the right. Everything works as it should but if I touch a large area of my hand (the fleshy part at the base of the thumb for instance) onto the screen, then release it and then press one of my arrows, the sprite moves in that direction for a few seconds, and then ACTION_UP is mysteriously triggered. The sprite stops and then if I release my finger and re-apply it to an arrow, the same thing happens. This goes on and on and eventually (randomly??) stops and everything work OK again. Test device & OS Google Nexus 10 Tablet running Jellybean 4.2.2 Code //Action upon which to switch actionMask = event.getActionMasked(); //Pointer Index of the currently touching pointer pointerIndex = event.getActionIndex(); //Number of pointers (for multi-touch) pointerCount = event.getPointerCount(); //ID of the pointer currently being processed (Multitouch) pointerID = event.getPointerId(pointerIndex); switch (actionMask){ //Primary pointer down case MotionEvent.ACTION_DOWN: { //if pressing left button then set moving left if (isLeftPressed(event.getX(), event.getY())){ renderer.setSpriteLeft(); } //if pressing right button then set moving right else if (isRightPressed(event.getX(), event.getY())){ renderer.setSpriteRight(); } //if pressing jump button then set sprite jumping else if (isJumpPressed(event.getX(),event.getY())){ renderer.setSpriteState('j', true); } break; }//End of case //Primary pointer up case MotionEvent.ACTION_UP:{ //When finger leaves the screen, stop sprite's horizontal movement renderer.setSpriteStopped(); break; }

  Read the article

• Direct3d - Code structure

  - by marcg11

  I'm learning directx in a master's degree and they taught us to have a GraphicsLayer class which is the one connecting with the direct3d library. That way this class is completly independent from the other classes (my game classes), meaning changing the renderer to OpenGL wouldn't require much effort but only changing the graphicLayer. This classe has it's LoadAssets, Paint methods, but I have a question, they told us to load all the assets inside this class. This means all these methods will be in the loadAssets method: D3DXCreateTextureFromFileEx(g_pD3DDevice,"tiles.png",0,0,1,0,D3DFMT_UNKNOWN,D3DPOOL_DEFAULT,D3DX_FILTER_NONE,D3DX_FILTER_NONE,NULL,NULL,NULL,&texTiles); // And more resources to load //... texTiles as you see is a LPDIRECT3DTEXTURE9 instance which is declared in the graphicLayer.h. So my question is, how do you manage all the resources? Do I have to declare in the .h all my game textures even if I'm not using them? How would you load only those resources there are in a scene and draw them in a code-strucured way?

  Read the article

• Collision detection with heightmap based terrain

  - by Truman's world

  I am developing a 2D tank game. The terrain is generated by Midpoint Displacement Algorithm, so the terrain is represented by an array: index ---> height of terrain [0] ---> 5 [1] ---> 8 [2] ---> 4 [3] ---> 6 [4] ---> 8 [5] ---> 9 ... ... The rendered mountain looks like this: * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * 0 1 2 3 4 5 ... I want tanks to be able to move smoothly on the terrain (I mean tanks can rotate according to the height when they move), but the surface of the terrain is not flat, it is polygonal. Can anyone give me some help with collision detection in this situation? Thanks in advance.

  Read the article

• How can I test if my rotated rectangle intersects a corner?

  - by Raven Dreamer

  I have a square, tile-based collision map. To check if one of my (square) entities is colliding, I get the vertices of the 4 corners, and test those 4 points against my collision map. If none of those points are intersecting, I know I'm good to move to the new position. I'd like to allow entities to rotate. I can still calculate the 4 corners of the square, but once you factor in rotation, those 4 corners alone don't seem to be enough information to determine if the entity is trying to move to a valid state. For example: In the picture below, black is unwalkable terrain, and red is the player's hitbox. The left scenario is allowed because the 4 corners of the red square are not in the black terrain. The right scenario would also be (incorrectly) allowed, because the player, cleverly turned at a 45* angle, has its corners in valid spaces, even if it is (quite literally) cutting the corner. How can I detect scenarios similar to the situation on the right?

  Read the article

• Drawing simple geometric figures with DrawUserPrimitives?

  - by Navy Seal

  I'm trying to draw a simple triangle based on an array of vertex. I've been searching for a tutorial and I found a simple example on riemers but I couldn't get it to work. I think it was made for XNA 3 and it seems there were some changes to XNA 4? Using this example: http://www.riemers.net/eng/Tutorials/XNA/Csharp/Series1/The_first_triangle.php I get this error: Additional information: The current vertex declaration does not include all the elements required by the current vertex shader. TextureCoordinate0 is missing. I'm not english so I'm having some trouble to understand everything. For what I understand error is confusing because I'm trying to draw a triangle color based and not texture based and it shouldn't need a texture. Also I saw some articles about dynamic shadows and lights and I would like to know if this is the kind of code used to do it with some tweaks like culling because I'm wondering if its heavy code for performance in real time.

  Read the article

• Bitmap font rendering, UV generation and vertex placement

  - by jack

  I am generating a bitmap, however, I am not sure on how to render the UV's and placement. I had a thread like this once before, but it was too loosely worded as to what I was looking to do. What I am doing right now is creating a large 1024x1024 image with characters evenly placed every 64 pixels. Here is an example of what I mean. I then save the bitmap X/Y information to a file (which is all multiples of 64). However, I am not sure how to properly use this information and bitmap to render. This falls into two different categories, UV generation and kerning. Now I believe I know how to do both of these, however, when I attempt to couple them together I will get horrendous results. For example, I am trying to render two different text arrays, "123" and "njfb". While ignoring the texture quality (I will be increasing the texture to provide more detail once I fix this issue), here is what it looks like when I try to render them. http://img64.imageshack.us/img64/599/badfontrendering.png Now for the algorithm. I am doing my letter placement with both GetABCWidth and GetKerningPairs. I am using GetABCWidth for the width of the characters, then I am getting the kerning information for adjust the characters. Does anyone have any suggestions on how I can implement my own bitmap font renderer? I am trying to do this without using external libraries such as angel bitmap tool or freetype. I also want to stick to the way the bitmap font sheet is generated so I can do extra effects in the future. Rendering Algorithm for(U32 c = 0, vertexID = 0, i = 0; c < numberOfCharacters; ++c, vertexID += 4, i += 6) { ObtainCharInformation(fontName, m_Text[c]); letterWidth = (charInfo.A + charInfo.B + charInfo.C) * scale; if(c != 0) { DWORD BytesReq = GetGlyphOutlineW(dc, m_Text[c], GGO_GRAY8_BITMAP, &gm, 0, 0, &mat); U8 * glyphImg= new U8[BytesReq]; DWORD r = GetGlyphOutlineW(dc, m_Text[c], GGO_GRAY8_BITMAP, &gm, BytesReq, glyphImg, &mat); for (int k=0; k<nKerningPairs; k++) { if ((kerningpairs[k].wFirst == previousCharIndex) && (kerningpairs[k].wSecond == m_Text[c])) { letterBottomLeftX += (kerningpairs[k].iKernAmount * scale); break; } } letterBottomLeftX -= (gm.gmCellIncX * scale); } SetVertex(letterBottomLeftX, 0.0f, zFight, vertexID); SetVertex(letterBottomLeftX, letterHeight, zFight, vertexID + 1); SetVertex(letterBottomLeftX + letterWidth, letterHeight, zFight, vertexID + 2); SetVertex(letterBottomLeftX + letterWidth, 0.0f, zFight, vertexID + 3); zFight -= 0.001f; float BottomLeftX = (F32)(charInfo.bitmapXOrigin) / (float)m_BitmapWidth; float BottomLeftY = (F32)(charInfo.bitmapYOrigin + charInfo.charBitmapHeight) / (float)m_BitmapWidth; float TopLeftX = BottomLeftX; float TopLeftY = (F32)(charInfo.bitmapYOrigin) / (float)m_BitmapWidth; float TopRightX = (F32)(charInfo.bitmapXOrigin + charInfo.B - charInfo.C) / (float)m_BitmapWidth; float TopRightY = TopLeftY; float BottomRightX = TopRightX; float BottomRightY = BottomLeftY; SetTextureCoordinate(TopLeftX, TopLeftY, vertexID + 1); SetTextureCoordinate(BottomLeftX, BottomLeftY, vertexID + 0); SetTextureCoordinate(BottomRightX, BottomRightY, vertexID + 3); SetTextureCoordinate(TopRightX, TopRightY, vertexID + 2); /// index setting letterBottomLeftX += letterWidth; previousCharIndex = m_Text[c]; }

  Read the article

• Illumination and Shading for computer graphics class

  - by Sam I Am

  I am preparing for my test tomorrow and this is one of the practice questions. I solved it partially but I am confused with the rest. Here is the problem: Consider a gray world with no ambient and specular lighting ( only diffuse lighting). The screen coordinates of a triangle P1,P2,P3, are P1=(100,100), P2= (300,150), P3 = (200, 200). The gray values at P!,P2,P3 are 1/2, 3/4, and 1/4 respectively. The light is at infinity and its direction and gray color are (1,1,1) and 1.0 respectively. The coefficients of diffused reflection is 1/2. The normals of P1,P2,P3 are N1= (0,0,1), N2 = (1,0,0), and N3 = (0,1,0) respectively. Consider the coordinates of three points P1,P2,P3 to be 0. Do not normalize the normals. I have computed that the illumination at the 3 vertices P1,P2,P3 is (1/4,3/8,1/8). Also I computed that interpolation coefficients of a point P inside the triangle whose coordinates are (220, 160) are given by (1/5,2/5,2/5). Now I have 4 more questions regarding this problem. 1) The illumination at P using Gouraud Shading is: i) 1/2 The answer is 1/2, but I have no idea how to compute it.. 2) The interpolated normal at P is given by i) (2/5, 2/5,1/5) ii) (1/2, 1/4, 1/4) iii) (3/5, 1/5, 1/5) 3) The interpolated color at P is given by: i) 1/2 Again, I know the correct answer but no idea how to solve it 4) The illumination at P using Phong Shading is i) 1/4 ii) 9/40 iii) 1/2

  Read the article

• Execute code at specific intervals, only once?

  - by Mathias Lykkegaard Lorenzen

  I am having an issue with XNA, where I want to execute some code in my Update method, but only at a given interval, and only once. I would like to avoid booleans to check if I've already called it once, if possible. My code is here: if ((gameTime.TotalGameTime.TotalMilliseconds % 500) == 0) { Caret.Visible = !Caret.Visible; } As you may have guessed, it's for a TextBox control, to animate the caret between invisible and visible states. I just have reason to believe that it is called twice or maybe even 3 times in a single update-call, which is bad, and makes it look unstable and jumpy.

  Read the article

• How to implement physical effect, perspective effect on Android

  - by asedra_le

  I'm researching about 2D game for Android to implement an Android Game Project. My project looks nearly like PaperToss. Instance of throwing a page, my game will throw a coin. Suppose that I have a coin put in three-dimensional that have coordinates at A(x,y,z). I throw that point ahead, after 1/100 second, that coin move from A(x,y,z) to A'(x',y',z'). By this way, I have two problems need to solve. Determine the formulas can be used to compute the coordinates of the coin at time t. This problem is under-researching. I have no idea to solve this problem. Mapping three-dimensional points to a two-dimensional and use those new coordinates (a two-dimensional coordinates) to draw our coin on screen. I have found two solutions for this problem: Orthographic projection & Perspective projection However, my old friend said that OpenGL supports to solve problems like my problems. Any body have experiences about my problems? Help me please :) Thank for reading my question.

  Read the article

• Animating DOM elements vs refreshing a single Canvas

  - by mgibsonbr

  A few years ago, when the HTML Canvas element was still kinda fresh, I wrote a small game in a rather "unusual" way: each game element had its own canvas, and frequently animated elements even had multiple canvases, one for each animation sprite. This way, the translation would be done by manipulating the DOM position of the canvases, while the sprite animation would consist of altering the visibility of the already drawn canvases. (z-indexes, of course, were the tricky part) It worked like a charm: even in IE6 with excanvas it showed a decent performance, and everything was rather consistent between browsers, including some smartphones. Now I'm thinking in writing a larger game engine in the same fashion, so I'm wondering whether it would be a good idea to do so in the current context (with all the advances in browsers and so on). I know I'm trading memory for time, so this needs to be customizable (even at runtime) for each machine the game will be running. But I believe using separate canvases would also help to avoid the game "freezing" on CPU spikes, since the translation would still happen even if the redraws lag for a while. Besides, the browsers' rendering engines are already optimized in may ways, so I'm guessing this scheme would also reduce the load on the CPU (in contrast to doing everything in JavaScript - specially the less optimized ones). It looks good in my head, but I'd like to hear the opinion of more experienced people before proceeding further. Is there any known drawback of doing this? I'm particulartly unexperienced in dealing with the GPU, so I wonder whether this "trick" would nullify any benefit of using a single, big canvas. Or maybe on modern devices it's overkill (though I'm skeptic about the claims that canvas+js - especially WebGL - will ever be a good alternative to native code). Any thoughts?

  Read the article

• Tessellation Texture Coordinates

  - by Stuart Martin

  Firstly some info - I'm using DirectX 11 , C++ and I'm a fairly good programmer but new to tessellation and not a master graphics programmer. I'm currently implementing a tessellation system for a terrain model, but i have reached a snag. My current system produces a terrain model from a height map complete with multiple texture coordinates, normals, binormals and tangents for rendering. Now when i was using a simple vertex and pixel shader combination everything worked perfectly but since moving to include a hull and domain shader I'm slightly confused and getting strange results. My terrain is a high detail model but the textured results are very large patches of solid colour. My current setup passes the model data into the vertex shader then through the hull into the domain and then finally into the pixel shader for use in rendering. My only thought is that in my hull shader i pass the information into the domain shader per patch and this is producing the large areas of solid colour because each patch has identical information. Lighting and normal data are also slightly off but not as visibly as texturing. Below is a copy of my hull shader that does not work correctly because i think the way that i am passing the data through is incorrect. If anyone can help me out but suggesting an alternative way to get the required data into the pixel shader? or by showing me the correct way to handle the data in the hull shader id be very thankful! cbuffer TessellationBuffer { float tessellationAmount; float3 padding; }; struct HullInputType { float3 position : POSITION; float2 tex : TEXCOORD0; float3 normal : NORMAL; float3 tangent : TANGENT; float3 binormal : BINORMAL; float2 tex2 : TEXCOORD1; }; struct ConstantOutputType { float edges[3] : SV_TessFactor; float inside : SV_InsideTessFactor; }; struct HullOutputType { float3 position : POSITION; float2 tex : TEXCOORD0; float3 normal : NORMAL; float3 tangent : TANGENT; float3 binormal : BINORMAL; float2 tex2 : TEXCOORD1; float4 depthPosition : TEXCOORD2; }; ConstantOutputType ColorPatchConstantFunction(InputPatch<HullInputType, 3> inputPatch, uint patchId : SV_PrimitiveID) { ConstantOutputType output; output.edges[0] = tessellationAmount; output.edges[1] = tessellationAmount; output.edges[2] = tessellationAmount; output.inside = tessellationAmount; return output; } [domain("tri")] [partitioning("integer")] [outputtopology("triangle_cw")] [outputcontrolpoints(3)] [patchconstantfunc("ColorPatchConstantFunction")] HullOutputType ColorHullShader(InputPatch<HullInputType, 3> patch, uint pointId : SV_OutputControlPointID, uint patchId : SV_PrimitiveID) { HullOutputType output; output.position = patch[pointId].position; output.tex = patch[pointId].tex; output.tex2 = patch[pointId].tex2; output.normal = patch[pointId].normal; output.tangent = patch[pointId].tangent; output.binormal = patch[pointId].binormal; return output; } Edited to include the domain shader:- [domain("tri")] PixelInputType ColorDomainShader(ConstantOutputType input, float3 uvwCoord : SV_DomainLocation, const OutputPatch<HullOutputType, 3> patch) { float3 vertexPosition; PixelInputType output; // Determine the position of the new vertex. vertexPosition = uvwCoord.x * patch[0].position + uvwCoord.y * patch[1].position + uvwCoord.z * patch[2].position; output.position = mul(float4(vertexPosition, 1.0f), worldMatrix); output.position = mul(output.position, viewMatrix); output.position = mul(output.position, projectionMatrix); output.depthPosition = output.position; output.tex = patch[0].tex; output.tex2 = patch[0].tex2; output.normal = patch[0].normal; output.tangent = patch[0].tangent; output.binormal = patch[0].binormal; return output; }

  Read the article

• How can player actions be "judged morally" in a measurable way?

  - by Sebastien Diot

  While measuring the player "skills" and "effort" is usually easy, adding some "less objective" statistics can give the player supplementary goals, especially in a MUD/RPG context. What I mean is that apart from counting how many orcs were killed, and gems collected, it would be interesting to have something along the line of the traditional Good/Evil, Lawful/Chaotic ranking of paper-based RPG, to add "dimension" to the game. But computers cannot differentiate good/evil effectively (nor can humans in many cases), and if you have a set of "laws" which are precise enough that you can tell exactly when the player breaks them, then it generally makes more sense to actually prevent them from doing that action in the first place. One example could be the creation/destruction axis (if players are at all allowed to create/build things), possibly in the form of the general effect of the player actions on "ecology". So what else is there left that can be effectively measured and would provide a sense of "moral" for the player? The more axis I have to measure, the more goals the player can have, and therefore the longer the game can last. This also gives the players more ways of "differentiating" themselves among hordes of other players of the same "class" and similar "kit".

  Read the article

• Grid pathfinding with a lot of entities

  - by Vee

  I'd like to explain this problem with a screenshot from a released game, DROD: Gunthro's Epic Blunder, by Caravel Games. The game is turn-based and tile-based. I'm trying to create something very similar (a clone of the game), and I've got most of the fundamentals done, but I'm having trouble implementing pathfinding. Look at the screenshot. The guys in yellow are friendly, and want to kill the roaches. Every turn, every guy in yellow pathfinds to the closest roach, and every roach pathfinds to the closest guy in yellow. By closest I mean the target with the shortest path, not a simple distance calculation. All of this without any kind of slowdown when loading the level or when passing turns. And all of the entities change position every turn. Also (not shown in screenshot), there can be doors that open and close and change the level's layout. Impressive. I've tried implementing pathfinding in my clone. First attempt was making every roach find a path to a yellow guy every turn, using a breadth-first search algorithm. Obviously incredibly slow with more than a single roach, and would get exponentially slower with more than a single yellow guy. Second attempt was mas making every yellow guy generate a pathmap (still breadth-first search) every time he moved. Worked perfectly with multiple roaches and a single yellow guy, but adding more yellow guys made the game slow and unplayable. Last attempt was implementing JPS (jump point search). Every entity would individually calculate a path to its target. Fast, but with a limited number of entities. Having less than half the entities in the screenshot would make the game slow. And also, I had to get the "closest" enemy by calculating distance, not shortest path. I've asked on the DROD forums how they did it, and a user replied that it was breadth-first search. The game is open source, and I took a look at the source code, but it's C++ (I'm using C#) and I found it confusing. I don't know how to do it. Every approach I tried isn't good enough. And I believe that DROD generates global pathmaps, somehow, but I can't understand how every entity find the best individual path to other entities that move every turn. What's the trick? This is a reply I just got on the DROD forums: Without having looked at the code I'd wager it's two (or so) pathmaps for the whole room: One to the nearest enemy, and one to the nearest friendly for every tile. There's no need to make a separate pathmap for every entity when the overall goal is "move towards nearest enemy/friendly"... just mark every tile with the number of moves it takes to the nearest target and have the entity chose the move that takes it to the tile with the lowest number. To be honest, I don't understand it that well.

  Read the article

• The technology behind 22can's curiosity

  - by Cameron Scully

  I don't have alot of experience with mobile apps and I definitely don't know much about MMO's but I was wondering what the basic architecture of a game like that would be (understandably some don't consider it a game, but it must use some game theory and implementation). Mainly, how are they able to send/recieve real time feed back of the cube being chipped away by thousands of players on their mobile devices? How is data of the cube's millions of pieces stored and accessed so quickly? Thanks

  Read the article

• Starting point for a simple game written in action script [closed]

  - by Hossein

  Possible Duplicate: AS3/Flash Game Dev: Looking for good & current step by step. Hi, I want to develop a simple game like: http://www.albinoblacksheep.com/games/falldown2 And then making it a bit more fancy. But I don't know where to start. I have already started AS3 so I know about the syntax and stuff, but I am kinda lost. Does anyone knows of a nice starting point or a tutorial that can help me with this? Thanks

  Read the article

• Are there any alternative JS ports of Box2D?

  - by Petteri Hietavirta

  I have been thinking about creating a top down 2D car game for HTML5. For my first game I wrote the physics and collisions my self but for this one I would like to use some ready made library. I found out Box2D and its JS port. http://box2d-js.sourceforge.net It seems to be quite old port, made in 2008. Is it lacking many features of current Box2D or does it have major issues with it? And are there any alternatives for it?

  Read the article

• Friction not working for Vehicle in BulletPhysics

  - by Manmohan Bishnoi

  I am creating a vehicle using bullet-physics engine (v 2.82). I created a ground ( btBoxShape ), a box and a vehicle (following the demo). But friction between ground and vehicle wheels seems not working. As soon as the vehicle is placed in 3d world, it starts moving forward. START : Steering works for the vehicle, but engineForce and brakingForce does not work (i.e. I cannot speed-up or stop the vehicle) : I create physics world like this : void initPhysics() { broadphase = new btDbvtBroadphase(); collisionConfiguration = new btDefaultCollisionConfiguration(); dispatcher = new btCollisionDispatcher(collisionConfiguration); solver = new btSequentialImpulseConstraintSolver(); dynamicsWorld = new btDiscreteDynamicsWorld(dispatcher, broadphase, solver, collisionConfiguration); dynamicsWorld->setGravity(btVector3(0, -9.81, 0)); // Debug Drawer bulletDebugugger.setDebugMode(btIDebugDraw::DBG_DrawWireframe); dynamicsWorld->setDebugDrawer(&bulletDebugugger); //groundShape = new btStaticPlaneShape(btVector3(0, 1, 0), 1); groundShape = new btBoxShape(btVector3(50, 3, 50)); fallShape = new btBoxShape(btVector3(1, 1, 1)); // Orientation and Position of Ground groundMotionState = new btDefaultMotionState(btTransform(btQuaternion(0, 0, 0, 1), btVector3(0, -3, 0))); btRigidBody::btRigidBodyConstructionInfo groundRigidBodyCI(0, groundMotionState, groundShape, btVector3(0, 0, 0)); groundRigidBody = new btRigidBody(groundRigidBodyCI); dynamicsWorld->addRigidBody(groundRigidBody); /////////////////////////////////////////////////////////////////////// // Vehicle Setup /////////////////////////////////////////////////////////////////////// vehicleChassisShape = new btBoxShape(btVector3(1.f, 0.5f, 2.f)); vehicleBody = new btCompoundShape(); localTrans.setIdentity(); localTrans.setOrigin(btVector3(0, 1, 0)); vehicleBody->addChildShape(localTrans, vehicleChassisShape); localTrans.setOrigin(btVector3(3, 0.f, 0)); vehicleMotionState = new btDefaultMotionState(localTrans); //vehicleMotionState = new btDefaultMotionState(btTransform(btQuaternion(0, 0, 0, 1), btVector3(3, 0, 0))); btVector3 vehicleInertia(0, 0, 0); vehicleBody->calculateLocalInertia(vehicleMass, vehicleInertia); btRigidBody::btRigidBodyConstructionInfo vehicleRigidBodyCI(vehicleMass, vehicleMotionState, vehicleBody, vehicleInertia); vehicleRigidBody = new btRigidBody(vehicleRigidBodyCI); dynamicsWorld->addRigidBody(vehicleRigidBody); wheelShape = new btCylinderShapeX(btVector3(wheelWidth, wheelRadius, wheelRadius)); { vehicleRayCaster = new btDefaultVehicleRaycaster(dynamicsWorld); vehicle = new btRaycastVehicle(vehicleTuning, vehicleRigidBody, vehicleRayCaster); // never deactivate vehicle vehicleRigidBody->setActivationState(DISABLE_DEACTIVATION); dynamicsWorld->addVehicle(vehicle); float connectionHeight = 1.2f; bool isFrontWheel = true; vehicle->setCoordinateSystem(rightIndex, upIndex, forwardIndex); // 0, 1, 2 // add wheels // front left btVector3 connectionPointCS0(CUBE_HALF_EXTENT-(0.3*wheelWidth), connectionHeight, 2*CUBE_HALF_EXTENT-wheelRadius); vehicle->addWheel(connectionPointCS0, wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, vehicleTuning, isFrontWheel); // front right connectionPointCS0 = btVector3(-CUBE_HALF_EXTENT+(0.3*wheelWidth), connectionHeight, 2*CUBE_HALF_EXTENT-wheelRadius); vehicle->addWheel(connectionPointCS0, wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, vehicleTuning, isFrontWheel); isFrontWheel = false; // rear right connectionPointCS0 = btVector3(-CUBE_HALF_EXTENT+(0.3*wheelWidth), connectionHeight, -2*CUBE_HALF_EXTENT+wheelRadius); vehicle->addWheel(connectionPointCS0, wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, vehicleTuning, isFrontWheel); // rear left connectionPointCS0 = btVector3(CUBE_HALF_EXTENT-(0.3*wheelWidth), connectionHeight, -2*CUBE_HALF_EXTENT+wheelRadius); vehicle->addWheel(connectionPointCS0, wheelDirectionCS0, wheelAxleCS, suspensionRestLength, wheelRadius, vehicleTuning, isFrontWheel); for (int i = 0; i < vehicle->getNumWheels(); i++) { btWheelInfo& wheel = vehicle->getWheelInfo(i); wheel.m_suspensionStiffness = suspensionStiffness; wheel.m_wheelsDampingRelaxation = suspensionDamping; wheel.m_wheelsDampingCompression = suspensionCompression; wheel.m_frictionSlip = wheelFriction; wheel.m_rollInfluence = rollInfluence; } } /////////////////////////////////////////////////////////////////////// // Orientation and Position of Falling body fallMotionState = new btDefaultMotionState(btTransform(btQuaternion(0, 0, 0, 1), btVector3(-1, 5, 0))); btScalar mass = 1; btVector3 fallInertia(0, 0, 0); fallShape->calculateLocalInertia(mass, fallInertia); btRigidBody::btRigidBodyConstructionInfo fallRigidBodyCI(mass, fallMotionState, fallShape, fallInertia); fallRigidBody = new btRigidBody(fallRigidBodyCI); dynamicsWorld->addRigidBody(fallRigidBody); } I step physics world like this : // does not work vehicle->applyEngineForce(maxEngineForce, WHEEL_REARLEFT); vehicle->applyEngineForce(maxEngineForce, WHEEL_REARRIGHT); // these also do not work vehicle->setBrake(gBreakingForce, WHEEL_REARLEFT); vehicle->setBrake(gBreakingForce, WHEEL_REARRIGHT); // this works vehicle->setSteeringValue(gVehicleSteering, WHEEL_FRONTLEFT); vehicle->setSteeringValue(gVehicleSteering, WHEEL_FRONTRIGHT); dynamicsWorld->stepSimulation(1 / 60.0f, 10); However If I apply brakingForce to all 4 wheels (i.e. including WHEEL_FRONTLEFT and WHEEL_FRONTRIGHT), then my vehicle stops, but keeps sliding/moving forward very very slowly. How do I fix this ?

  Read the article

• Capitalizing on JavaScript's prototypal inheritance

  - by keithjgrant

  JavaScript has a class-free object system in which objects inherit properties directly from other objects. This is really powerful, but it is unfamiliar to classically trained programmers. If you attempt to apply classical design patterns directly to JavaScript, you will be frustrated. But if you learn to work with JavaScript's prototypal nature, your efforts will be rewarded. ... It is Lisp in C's clothing. -Douglas Crockford What does this mean for a game developer working with canvas and HTML5? I've been looking over this question on useful design patterns in gaming, but prototypal inheritance is very different than classical inheritance, and there are surely differences in the best way to apply some of these common patterns. For example, classical inheritance allows us to create a moveableEntity class, and extend that with any classes that move in our game world (player, monster, bullet, etc.). Sure, you can strongarm JavaScript to work that way, but in doing so, you are kind of fighting against its nature. Is there a better approach to this sort of problem when we have prototypal inheritance at our fingertips?

  Read the article

• How to move Objects smoothly like swimming arround

  - by philipp

  I have a Box2D project that is about to create a view where the user looks from the Sky onto Water. Or perhaps on a bathtub filled with water or something like this. The Object which holds the fluid actually does not matter, what matters is the movement of the bodies, because they should move like drops of grease on a soup, or wood on water, I can even imagine the the fluid is mercurial, extreme heavy and "lazy". How can I manipulate the bodies (every frame or time by time) to make them move like this? I started with randomly manipulation their linear velocity, but I turned out that this not very smooth and looks quite hard. Is it a better idea to check their velocity and apply impulses? Is there any example? Greetings philipp

  Read the article

• Seeking an C/C++ OBJ geometry read/write that does not modify the representation

  - by Blake Senftner

  I am seeking a means to read and write OBJ geometry files with logic that does not modify the geometry representation. i.e. read geometry, immediately write it, and a diff of the source OBJ and the one just written will be identical. Every OBJ writing utility I've been able to find online fails this test. I am writing small command line tools to modify my OBJ geometries, and I need to write my results, not just read the geometry for rendering purposes. Simply needing to write the geometry knocks out 95% of the OBJ libraries on the web. Also, many of the popular libraries modify the geometry representation. For example, Nat Robbin's GLUT library includes the GLM library, which both converts quads to triangles, as well as reverses the topology (face ordering) of the geometry. It's still the same geometry, but if your tool chain expects a given topology, such as for rigging or morph targets, then GLM is useless. I'm not rendering in these tools, so dependencies like OpenGL or GLUT make no sense. And god forbid, do not "optimize" the geometry! Redundant vertices are on purpose for maintaining oneself on cache with our weird little low memory mobile devices.

  Read the article

• Constructive criticsm on my linear sampling Gaussian blur

  - by Aequitas

  I've been attempting to implement a gaussian blur utilising linear sampling, I've come across a few articles presented on the web and a question posed here which dealt with the topic. I've now attempted to implement my own Gaussian function and pixel shader drawing reference from these articles. This is how I'm currently calculating my weights and offsets: int support = int(sigma * 3.0) weights.push_back(exp(-(0*0)/(2*sigma*sigma))/(sqrt(2*pi)*sigma)); total += weights.back(); offsets.push_back(0); for (int i = 1; i <= support; i++) { float w1 = exp(-(i*i)/(2*sigma*sigma))/(sqrt(2*pi)*sigma); float w2 = exp(-((i+1)*(i+1))/(2*sigma*sigma))/(sqrt(2*pi)*sigma); weights.push_back(w1 + w2); total += 2.0f * weights[i]; offsets.push_back(w1 / weights[i]); } for (int i = 0; i < support; i++) { weights[i] /= total; } Here is an example of my vertical pixel shader: vec3 acc = texture2D(tex_object, v_tex_coord.st).rgb*weights[0]; vec2 pixel_size = vec2(1.0 / tex_size.x, 1.0 / tex_size.y); for (int i = 1; i < NUM_SAMPLES; i++) { acc += texture2D(tex_object, (v_tex_coord.st+(vec2(0.0, offsets[i])*pixel_size))).rgb*weights[i]; acc += texture2D(tex_object, (v_tex_coord.st-(vec2(0.0, offsets[i])*pixel_size))).rgb*weights[i]; } gl_FragColor = vec4(acc, 1.0); Am I taking the correct route with this? Any criticism or potential tips to improving my method would be much appreciated.

  Read the article

• Open GL Android frame-by-frame animation tutorial/example code

  - by Trick

  My first question was asked wrong, so I need to ask again :) I found out, that I will have to do an OpenGL animation for my Android game. The closest (known) example is Talking Tom (but I don't know how they did the animations). I have large PNGs which I would like to put into a animation. For example - 30 PNGs 427×240px at 8 FPS. I know some things already about Open GL, but I am used to learn from example code. And it is quicker that way (so I don't need to invent hot water all over again :)). Does anybody has any points to direct me?

  Read the article

< Previous Page | 453 454 455 456 457 458 459 460 461 462 463 464  | Next Page >