Search Results

Search found 28230 results on 1130 pages for 'embedded development'.

Page 482/1130 | < Previous Page | 478 479 480 481 482 483 484 485 486 487 488 489  | Next Page >

• Multiple Vertex Buffers per Mesh

  - by Daniel

  I've run into the situation where the size of my mesh with all its vertices and indices, is larger than the (optimal) vertex buffer object upper limit (~8MB). I was wondering if I can sub-divide the mesh across multiple vertex buffers, and somehow retain validity of the indices. Ie a triangle with a indice at the first vertex, and an indice at the last (ie in seperate VBOs). All the while maintaining this within Vertex Array Objects. My thoughts are, save myself the hassle, and for meshes (messes :P) such as this, just use the necessary size ( 8MB); which is what I do at the moment. But ideally my buffer manager (wip) at the moment is using optimal sizes; I may just have to make a special case then... Any ideas? If necessary, a simple C++ code example is appreciated. Note: I have also cross-posted this on stackoverflow, as I was not sure as to which it would be more suitable (its partly a design question).

  Read the article

• Having troubles with LibNoise.XNA and generating tileable maps

  - by Jon

  Following up on my previous post, I found a wonderful port of LibNoise for XNA. I've been working with it for about 8 hours straight and I'm tearing my hair out - I just can not get maps to tile, I can't figure out how to do this. Here's my attempt: Perlin perlin = new Perlin(1.2, 1.95, 0.56, 12, 2353, QualityMode.Medium); RiggedMultifractal rigged = new RiggedMultifractal(); Add add = new Add(perlin, rigged); // Initialize the noise map int mapSize = 64; this.m_noiseMap = new Noise2D(mapSize, perlin); //this.m_noiseMap.GeneratePlanar(0, 1, -1, 1); // Generate the textures this.m_noiseMap.GeneratePlanar(-1,1,-1,1); this.m_textures[0] = this.m_noiseMap.GetTexture(this.graphics.GraphicsDevice, Gradient.Grayscale); this.m_noiseMap.GeneratePlanar(mapSize, mapSize * 2, mapSize, mapSize * 2); this.m_textures[1] = this.m_noiseMap.GetTexture(this.graphics.GraphicsDevice, Gradient.Grayscale); this.m_noiseMap.GeneratePlanar(-1, 1, -1, 1); this.m_textures[2] = this.m_noiseMap.GetTexture(this.graphics.GraphicsDevice, Gradient.Grayscale); The first and third ones generate fine, they create a perlin noise map - however the middle one, which I wanted to be a continuation of the first (As per my original post), is just a bunch of static. How exactly do I get this to generate maps that connect to each other, by entering in the mapsize * tile, using the same seed, settings, etc.?

  Read the article

• Precise Touch Screen Dragging Issue: Trouble Aligning with the Finger due to Different Screen Resolution

  - by David Dimalanta

  Please, I need your help. I'm trying to make a game that will drag-n-drop a sprite/image while my finger follows precisely with the image without being offset. When I'm trying on a 900x1280 (in X [900] and Y [1280]) screen resolution of the Google Nexus 7 tablet, it follows precisely. However, if I try testing on a phone smaller than 900x1280, my finger and the image won't aligned properly and correctly except it still dragging. This is the code I used for making a sprite dragging with my finger under touchDragged(): x = ((screenX + Gdx.input.getX())/2) - (fruit.width/2); y = ((camera_2.viewportHeight * multiplier) - ((screenY + Gdx.input.getY())/2) - (fruit.width/2)); This code above will make the finger and the image/sprite stays together in place while dragging but only works on 900x1280. You'll be wondering there's camera_2.viewportHeight in my code. Here are for two reasons: to prevent inverted drag (e.g. when you swipe with your finger downwards, the sprite moves upward instead) and baseline for reading coordinate...I think. Now when I'm adding another orthographic camera named camera_1 and changing its setting, I recently used it for adjusting the falling object by meter per pixel. Also, it seems effective independently for smartphones that has smaller resolution and this is what I used here: show() camera_1 = new OrthographicCamera(); camera_1.viewportHeight = 280; // --> I set it to a smaller view port height so that the object would fall faster, decreasing the chance of drag force. camera_1.viewportWidth = 196; // --> Make it proportion to the original screen view size as possible. camera_1.position.set(camera_1.viewportWidth * 0.5f, camera_1.viewportHeight * 0.5f, 0f); camera_1.update(); touchDragged() x = ((screenX + (camera_1.viewportWidth/Gdx.input.getX()))/2) - (fruit.width/2); y = ((camera_1.viewportHeight * multiplier) - ((screenY + (camera_1.viewportHeight/Gdx.input.getY()))/2) - (fruit.width/2)); But the result instead of just following the image/sprite closely to my finger, it still has a space/gap between the sprite/image and the finger. It is possibly dependent on coordinates based on the screen resolution. I'm trying to drag the blueberry sprite with my finger. My expectation did not met since I want my finger and the sprite/image (blueberry) to stay close together while dragging until I release it. Here's what it looks like: I got to figure it out how to make independent on all screen sizes by just following the image/sprite closely to my finger while dragging even on most different screen sizes instead.

  Read the article

• Bouncing ball slowing down over time

  - by user46610

  I use the unreal engine 4 to bounce a ball off of walls in a 2D space, but over time the ball gets slower and slower. Movement happens in the tick function of the ball FVector location = GetActorLocation(); location.X += this->Velocity.X * DeltaSeconds; location.Y += this->Velocity.Y * DeltaSeconds; SetActorLocation(location, true); When a wall gets hit I get a Hit Event with the normal of the collision. This is how I calculate the new velocity of the ball: FVector2D V = this->Velocity; FVector2D N = FVector2D(HitNormal.X, HitNormal.Y); FVector2D newVelocity = -2 * (V.X * N.X + V.Y * N.Y) * N + V; this->Velocity = newVelocity; Over time, the more the ball bounced around, the velocity gets smaller and smaller. How do I prevent speed loss when bouncing off walls like that? It's supposed to be a perfect bounce without friction or anything.

  Read the article

• I'm looking to learn how to apply traditional animation techniques to my graphics engine - are there any tutorials or online-resources that can help?

  - by blueberryfields

  There are many traditional animation techniques - such as blurring of motion, motion along an elliptical curve rather than a straight line, counter-motion before beginning of movement - which help with creating the appearance of a realistic 3D animated character. I'm looking to incorporate tools and short cuts for some of these into my graphics engine, to make it easier for my end users to use these techniques in their animations. Is there a good resource listing the techniques and the principles behind them, especially how they might apply to a graphics engine or 3D animation?

  Read the article

• Matrix.CreateBillboard centre rotation problem

  - by Chris88

  I'm having an issue with Matrix.CreateBillboard and a textured Quad where the center axis seems to be positioned incorrectly to the quad object which is rotating around a center point: Using: BasicEffect quadEffect; Drawing the quad shape: Left = Vector3.Cross(Normal, Up); Vector3 uppercenter = (Up * height / 2) + origin; LowerLeft = uppercenter + (Left * width / 2); LowerRight = uppercenter - (Left * width / 2); UpperLeft = LowerLeft - (Up * height); UpperRight = LowerRight - (Up * height); Where height and width are float values passed in (it draws a square) Draw method: quadEffect.View = camera.view; quadEffect.Projection = camera.projection; quadEffect.World = Matrix.CreateBillboard(Origin, camera.cameraPosition, Vector3.Up, camera.cameraDirection); GraphicsDevice.BlendState = BlendState.Additive; foreach (EffectPass pass in quadEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawUserIndexedPrimitives <VertexPositionNormalTexture>( PrimitiveType.TriangleList, Vertices, 0, 4, Indexes, 0, 2); } GraphicsDevice.BlendState = BlendState.Opaque; In the screenshots below i draw the image at Vector3(32f, 0f, 32f) The screenshots below show you the position of the quad in relation to the red cross. The red cross shows where it should be drawn http://i.imgur.com/YwRYj.jpg http://i.imgur.com/ZtoHL.jpg It rotates around the red cross position

  Read the article

• (int) Math.floor(x / TILESIZE) or just (int) (x / TILESIZE)

  - by Aidan Mueller

  I have a Array that stores my map data and my Tiles are 64X64. Sometimes I need to convert from pixels to units of tiles. So I was doing: int x int y public void myFunction() { getTile((int) Math.floor(x / 64), (int) Math.floor(y / 64)).doOperation(); } But I discovered by using (I'm using java BTW) System.out.println((int) (1 / 1.5)) that converting to an int automatically rounds down. This means that I can replace the (int) Math.floor with just x / 64. But if I run this on a different OS do you think it might give a different result? I'm just afraid there might be some case where this would round up and not down. Should I keep doing it the way I was and maybe make a function like convert(int i) to make it easier? Or is it OK to just do x / 64?

  Read the article

• Game programming basics under Windows

  - by dreta

  I've been trying to learn some Windows programming using the Win32 API. Now, i'm used to working with the OS layer being abstracted away, mostly thanks to libraries like SFML or Allegro. Could you guys help me out and tell me if i'm thinking right here. The place for my gameloop is where i'm reading the messages? while (TRUE) { if (PeekMessage (&msg, NULL, 0, 0, PM_REMOVE)) { if (msg.message == WM_QUIT) break ; TranslateMessage (&msg) ; DispatchMessage (&msg) ; } else { //my game loop goes here } } Now the slightly bigger issue, that is, drawing. Do i run my drawing where i normaly do it, inside the game loop after the game logic? Or do i do it when WM_PAIN is being called and just call InvalidateRect (hwnd, NULL, TRUE); when i want to draw? This does feel weird, the WM_PAINT is a queued message, so i don't know for sure when it'll be called. So if i wanted to avoid this, do i just get the device handle inside the game loop and only ValidateRect (hwnd, NULL); in the WM_PAINT case (beside the ValidateRect (hwnd, NULL); called after drawing in the game loop)? Actually, now that i think about it, do i even need WM_PAINT in this situation or can i skip it and let DefWindowProc handle it (does it validate the screen if WM_PAINT isn't processed)? If this is any important, i'm setting up my code for OpenGL.

  Read the article

• HedgeWar code confusion

  - by BluFire

  I looked at an open source project(HedgeWars) that was built using many programming languages such as C++ and Java. While I was looking through the code, I couldn't help noticing that all the math and physics were gone from the Java code. HedgeWars I imported the project file called "SDL-android-project" which was a sub folder to "android build" and project files. My question is where is all the math and physics inside the code? Do I have to look at the C++ code in order to see it? I think Hedgewars was originally programmed in C++ but the files are confusing be because of its size and the fact that it has several programming languages inside.

  Read the article

• How do I draw video frames onto the screen permanently using XNA?

  - by izb

  I have an app that plays back a video and draws the video onto the screen at a moving position. When I run the app, the video moves around the screen as it plays. Here is my Draw method... protected override void Draw(GameTime gameTime) { Texture2D videoTexture = null; if (player.State != MediaState.Stopped) videoTexture = player.GetTexture(); if (videoTexture != null) { spriteBatch.Begin(); spriteBatch.Draw( videoTexture, new Rectangle(x++, 0, 400, 300), /* Where X is a class member */ Color.White); spriteBatch.End(); } base.Draw(gameTime); } The video moves horizontally acros the screen. This is not exactly as I expected since I have no lines of code that clear the screen. My question is why does it not leave a trail behind? Also, how would I make it leave a trail behind?

  Read the article

• Blender - creating bones from transform matrices

  - by user975135

  Notice: this is for the Blender 2.5/2.6 API. Back in the old days in the Blender 2.4 API, you could easily create a bone from a transform matrix in your 3d file as EditBones had an attribute named "matrix", which was an armature-space matrix you could access and modify. The new 2.5+ API still has the "matrix" attribute for EditBones, but for some unknown reason it is now read-only. So how to create EditBones from transform matrices? I could only find one thing: a new "transform()" function, which takes a Matrix too. Transform the the bones head, tail, roll and envelope (when the matrix has a scale component). Perfect, but you already need to have some values (loc/rot/scale) for your bone, otherwise transforming with a matrix like this will give you nothing, your bone will be a zero-sized bone which will be deleted by Blender. if you create default bone values first, like this: bone.tail = mathutils.Vector([0,1,0]) Then transform() will work on your bone and it might seem to create correct bones, but setting a tail position actually generates a matrix itself, use transform() and you don't get the matrix from your model file on your EditBone, but the multiplication of your matrix with the bone's existing one. This can be easily proven by comparing the matrices read from the file with EditBone.matrix. Again it might seem correct in Blender, but now export your model and you see your animations are messed up, as the bind pose rotations of the bones are wrong. I've tried to find an alternative way to assign the transformation matrix from my file to my EditBone with no luck.

  Read the article

• Marshalling C# Structs into DX11 cbuffers

  - by Craig

  I'm having some issues with the packing of my structure in C# and passing them through to cbuffers I have registered in HLSL. When I pack my struct in one manner the information seems to be able to pass to the shader: [StructLayout(LayoutKind.Explicit, Size = 16)] internal struct TestStruct { [FieldOffset(0)] public Vector3 mEyePosition; [FieldOffset(12)] public int type; } This works perfectly when used against this HLSL fragment: cbuffer PerFrame : register(b0) { Vector3 eyePos; int type; } float3 GetColour() { float3 returnColour = float(0.0f, 0.0f, 0.0f); switch(type) { case 0: returnColour = float3(1.0f, 0.0f, 0.0f); break; case 1: returnColour = float3(0.0f, 1.0f, 0.0f); break; case 2: returnColour = float3(0.0f, 0.0f, 1.0f); break; } return returnColour; } However, when I use the following structure definitions... // Note this is 16 because HLSL packs in 4 float 'chunks'. // It is also simplified, but still demonstrates the problem. [StructLayout(Layout.Explicit, Size = 16)] internal struct InternalTestStruct { [FieldOffset(0)] public int type; } [StructLayout(LayoutKind.Explicit, Size = 32)] internal struct TestStruct { [FieldOffset(0)] public Vector3 mEyePosition; //Missing 4 bytes here for correct packing. [FieldOffset(16)] public InternalTestStruct mInternal; } ... the following HLSL fragment no longer works. struct InternalType { int type; } cbuffer PerFrame : register(b0) { Vector3 eyePos; InternalType internalStruct; } float3 GetColour() { float3 returnColour = float(0.0f, 0.0f, 0.0f); switch(internaltype.type) { case 0: returnColour = float3(1.0f, 0.0f, 0.0f); break; case 1: returnColour = float3(0.0f, 1.0f, 0.0f); break; case 2: returnColour = float3(0.0f, 0.0f, 1.0f); break; } return returnColour; } Is there a problem with the way I am packing the struct, or is it another issue? To re-iterate: I can pass a struct in a cbuffer so long as it does not contain a nested struct.

  Read the article

• why is glVertexAttribDivisor crashing?

  - by 2am

  I am trying to render some trees with instancing. This is rather weird, but before sleeping yesterday night, I checked the code, and it was in a running state, when I got up this morning, it is crashing when I am calling glVertexAttribDivisor I haven't changed any code since yesterday. Here is how I am sending data to GPU for instancing. glGenBuffers(1, &iVBO); glBindBuffer(GL_ARRAY_BUFFER, iVBO); glBufferData(GL_ARRAY_BUFFER, (ml_instance->i_positions.size()*sizeof(glm::vec4)) , NULL, GL_STATIC_DRAW); glBufferSubData(GL_ARRAY_BUFFER, 0, (ml_instance->i_positions.size()*sizeof(glm::vec4)), &ml_instance->i_positions[0]); And then in vertex specification-- glBindBuffer(GL_ARRAY_BUFFER, iVBO); glVertexAttribPointer(i_positions, 4, GL_FLOAT, GL_FALSE, 0, 0); glEnableVertexAttribArray(i_positions); glVertexAttribDivisor(i_positions,1); // **THIS IS WHERE THE PROGRAM CRASHES** glDrawElementsInstanced(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0,TREES_INSTANCE_COUNT); I have checked ml_instance->i_positions, it has all the data that needs to render. I have checked the value of i_positions in vertex shader, it is the same as whatever I have defined there. I am little out of ideas here, everything looks pretty much fine. What am I missing?

  Read the article

• Convex Hull for Concave Objects

  - by Lighthink

  I want to implement GJK and I want it to handle concave shapes too (almost all my shapes are concave). I've thought of decomposing the concave shape into convex shapes and then building a hierarchical tree out of convex shapes, but I do not know how to do it. Nothing I could find on the Internet about it wasn't satisfying my needs, so maybe someone can point me in the right direction or give a full explanation.

  Read the article

• Computer Games Technolgy or Software Engineering?

  - by Suleman Anwar

  I'm in the last year of my college and going to university next year. Could you tell me what the difference between Software Engineering and Computer Games Technology is? I know a bit of both but don't know the actual difference. I'm kind off in a dilemma between these two. I want to be a programmer, I'd love to go into gaming but I heard getting a job within a computer games company is really hard.

  Read the article

• How is constant buffer allocation handled in DX11?

  - by Marek

  I'm starting with DX11 and I'm not sure if I'm doing the things right. I want to have both pixel and vertex shader program in one file. Both use some shared and some different constant buffers. So it looks like this: Shader.fx cbuffer ForVS : register(b0) { float4x4 wvp; }; cbuffer ForVSandPS : register(b1) { float4 stuff; float4 stuff2; }; cbuffer ForVS2 : register(b2) { float4 stuff; float4 stuff2; }; cbuffer ForPS : register(b3) { float4 stuff; float4 stuff2; }; .... And in code I use mContext->VSSetConstantBuffers( 0, 1, bufferVS); mContext->VSSetConstantBuffers( 1, 1, bufferVS_PS); mContext->VSSetConstantBuffers( 2, 1, bufferVS2); mContext->PSSetConstantBuffers( 1, 1, bufferVS_PS); mContext->PSSetConstantBuffers( 3, 1, bufferPS); The numbering of buffers in PS is what bugs me, is it alright to bind random slots to shaders (in this example 1 and 3)? Does that mean it still uses just two buffers or does it initialize 0 and 2 buffer pointers to empty? Thank you.

  Read the article

• Why are textures always square powers of two? What if they aren't?

  - by Keavon

  Why are the resolution of textures in games always a power of two (128x128, 256x256, 512x512, 1024x1024, etc.)? Wouldn't it be smart to save on the game's file size and make the texture exactly fit the UV unwrapped model? What would happen if there was a texture that was not a power of two? Would it be incorrect to have a texture be something like 256x512, or 512x1024? Or would this cause the problems that non-power-of-two textures may cause?

  Read the article

• Basic procedural generated content works, but how could I do the same in reverse?

  - by andrew

  My 2D world is made up of blocks. At the moment, I create a block and assign it a number between 1 and 4. The number assigned to the nth block is always the same (i.e if the player walks backwards or restarts the game.) and is generated in the function below. As shown here by this animation, the colours represent the number. function generate_data(n) math.randomseed(n) -- resets the random so that the 'random' number for n is always the same math.random() -- fixes lua random bug local no = math.random(4) --print(no, n) return no end Now I want to limit the next block's number - a block of 1 will always have a block 2 after it, while block 2 will either have a block 1,2 or 3 after it, etc. Before, all the blocks data was randomly generated, initially, and then saved. This data was then loaded and used instead of being randomly called. While working this way, I could specify what the next block would be easily and it would be saved for consistency. I have now removed this saving/loading in favour of procedural generation as I realised that save whiles would get very big after travelling. Back to the present. While travelling forward (to the right), it is easy to limit what the next blocks number will be. I can generate it at the same time as the other data. The problem is when travelling backwards (to the left) I can not think of a way to load the previous block so that it is always the same. Does anyone have any ideas on how I could sort this out?

  Read the article

• How can I improve my Animation

  - by sharethis

  The first approaches in animation for my game relied mostly on sine and cosine functions with the time as parameter. Here is an example of a very basic jump I implemented. if(jumping) { height = sin(time); if(height < 0) jumping = false; // player landed player.position.z = height; } if(keydown(SPACE) && !jumping) { jumping = true; time = now(); // store the starting time } So my player jumped in a perfect sine function. That seems quite natural, because he slows down when he reached the top position, and in the fall he speeds up again. But patching every animation out of sine and cosine is stretched to its limits soon. So can I improve my animation and provide a more abstract layer?

  Read the article

• How should I plan the inheritance structure for my game?

  - by Eric Thoma

  I am trying to write a platform shooter in C++ with a really good class structure for robustness. The game itself is secondary; it is the learning process of writing it that is primary. I am implementing an inheritance tree for all of the objects in my game, but I find myself unsure on some decisions. One specific issue that it bugging me is this: I have an Actor that is simply defined as anything in the game world. Under Actor is Character. Both of these classes are abstract. Under Character is the Philosopher, who is the main character that the user commands. Also under Character is NPC, which uses an AI module with stock routines for friendly, enemy and (maybe) neutral alignments. So under NPC I want to have three subclasses: FriendlyNPC, EnemyNPC and NeutralNPC. These classes are not abstract, and will often be subclassed in order to make different types of NPC's, like Engineer, Scientist and the most evil Programmer. Still, if I want to implement a generic NPC named Kevin, it would nice to be able to put him in without making a new class for him. I could just instantiate a FriendlyNPC and pass some values for the AI machine and for the dialogue; that would be ideal. But what if Kevin is the one benevolent Programmer in the whole world? Now we must make a class for him (but what should it be called?). Now we have a character that should inherit from Programmer (as Kevin has all the same abilities but just uses the friendly AI functions) but also should inherit from FriendlyNPC. Programmer and FriendlyNPC branched away from each other on the inheritance tree, so inheriting from both of them would have conflicts, because some of the same functions have been implemented in different ways on the two of them. 1) Is there a better way to order these classes to avoid these conflicts? Having three subclasses; Friendly, Enemy and Neutral; from each type of NPC; Engineer, Scientist, and Programmer; would amount to a huge number of classes. I would share specific implementation details, but I am writing the game slowly, piece by piece, and so I haven't implemented past Character yet. 2) Is there a place where I can learn these programming paradigms? I am already trying to take advantage of some good design patterns, like MVC architecture and Mediator objects. The whole point of this project is to write something in good style. It is difficult to tell what should become a subclass and what should become a state (i.e. Friendly boolean v. Friendly class). Having many states slows down code with if statements and makes classes long and unwieldy. On the other hand, having a class for everything isn't practical. 3) Are there good rules of thumb or resources to learn more about this? 4) Finally, where does templating come in to this? How should I coordinate templates into my class structure? I have never actually taken advantage of templating honestly, but I hear that it increases modularity, which means good code.

  Read the article

• SWF file not playing after being published

  - by rsquare

  I'm trying to run the "connector" example that comes bundled with the SmartFoxServer 2X downloads.. There it connects to the server and loads the correct configuration file. When I run it in Adobe Flash Professional 5, it runs correctly and connects to the server but after being published as SWF movie, it doesnt work. It loads the configuration file but can't connect and gives an error connection failure: ERROR 2048. This is the example I'm talking about.

  Read the article

• Writing to a structured buffer with a compute shader (D3D11)

  - by Vertexwahn

  I have some problems writing to a structured buffer. First I create a structured buffer that is filled with float values beginning from 0 to 99. Afterwards a copy the structured buffer to a CPU accessible buffer is made to print the content of the structured buffer to the console. The output is as expected (Numbers 0 to 99 appear on the console). Afterwards I use a compute shader that should change the contents of the structured buffer: RWStructuredBuffer<float> Result : register( u0 ); [numthreads(1, 1, 1)] void CS_main( uint3 GroupId : SV_GroupID ) { Result[GroupId.x] = GroupId.x * 10; } But the compute shader does not change the contents of the structured buffer. The source code can be found here (main.cpp): https://bitbucket.org/Vertexwahn/cmakedemos/src/4abb067afd5781b87a553c4c720956668adca22a/D3D11ComputeShader/src/main.cpp?at=default FillCS.hlsl: https://bitbucket.org/Vertexwahn/cmakedemos/src/4abb067afd5781b87a553c4c720956668adca22a/D3D11ComputeShader/src/FillCS.hlsl?at=default

  Read the article

• How can I store all my level data in a single file instead of spread out over many files?

  - by Jon

  I am currently generating my level data, and saving to disk to ensure that any modifications done to the level are saved. I am storing "chunks" of 2048x2048 pixels into a file. Whenever the player moves over a section that doesn't have a file associated with the position, a new file is created. This works great, and is very fast. My issue, is that as you are playing the file count gets larger and larger. I'm wondering what are techniques that can be used to alleviate the file count, without taking a performance hit. I am interested in how you would store/seek/update this data in a single file instead of multiple files efficiently.

  Read the article

• Annoying flickering of vertices and edges (possible z-fighting)

  - by Belgin

  I'm trying to make a software z-buffer implementation, however, after I generate the z-buffer and proceed with the vertex culling, I get pretty severe discrepancies between the vertex depth and the depth of the buffer at their projected coordinates on the screen (i.e. zbuffer[v.xp][v.yp] != v.z, where xp and yp are the projected x and y coordinates of the vertex v), sometimes by a small fraction of a unit and sometimes by 2 or 3 units. Here's what I think is happening: Each triangle's data structure holds the plane's (that is defined by the triangle) coefficients (a, b, c, d) computed from its three vertices from their normal: void computeNormal(Vertex *v1, Vertex *v2, Vertex *v3, double *a, double *b, double *c) { double a1 = v1 -> x - v2 -> x; double a2 = v1 -> y - v2 -> y; double a3 = v1 -> z - v2 -> z; double b1 = v3 -> x - v2 -> x; double b2 = v3 -> y - v2 -> y; double b3 = v3 -> z - v2 -> z; *a = a2*b3 - a3*b2; *b = -(a1*b3 - a3*b1); *c = a1*b2 - a2*b1; } void computePlane(Poly *p) { double x = p -> verts[0] -> x; double y = p -> verts[0] -> y; double z = p -> verts[0] -> z; computeNormal(p -> verts[0], p -> verts[1], p -> verts[2], &p -> a, &p -> b, &p -> c); p -> d = p -> a * x + p -> b * y + p -> c * z; } The z-buffer just holds the smallest depth at the respective xy coordinate by somewhat casting rays to the polygon (I haven't quite got interpolation right yet so I'm using this slower method until I do) and determining the z coordinate from the reversed perspective projection formulas (which I got from here: double z = -(b*Ez*y + a*Ez*x - d*Ez)/(b*y + a*x + c*Ez - b*Ey - a*Ex); Where x and y are the pixel's coordinates on the screen; a, b, c, and d are the planes coefficients; Ex, Ey, and Ez are the eye's (camera's) coordinates. This last formula does not accurately give the exact vertices' z coordinate at their projected x and y coordinates on the screen, probably because of some floating point inaccuracy (i.e. I've seen it return something like 3.001 when the vertex's z-coordinate was actually 2.998). Here is the portion of code that hides the vertices that shouldn't be visible: for(i = 0; i < shape.nverts; ++i) { double dist = shape.verts[i].z; if(z_buffer[shape.verts[i].yp][shape.verts[i].xp].z < dist) shape.verts[i].visible = 0; else shape.verts[i].visible = 1; } How do I solve this issue? EDIT I've implemented the near and far planes of the frustum, with 24 bit accuracy, and now I have some questions: Is this what I have to do this in order to resolve the flickering? When I compare the z value of the vertex with the z value in the buffer, do I have to convert the z value of the vertex to z' using the formula, or do I convert the value in the buffer back to the original z, and how do I do that? What are some decent values for near and far? Thanks in advance.

  Read the article

• Sanity checks vs file sizes

  - by Richard Fabian

  In your game assets do you make room for explicit sanity checks, or do you have some generally expected bounds which you assert? I've been thinking about how we compress data and thought that it's much better to have the former, and less of the latter. If your data can exceed your normal valid ranges, but if it does it's an error, then surely that implies you're not compressing the data well enough? What do you do to find out if your data is compressed as far as it can be, and what do you use to ensure your data isn't corrupted and ensure it's an official release? EDIT I'm not interested in sanity checking the file size, but instead, how you manage your sanity checks and whether you arrange the excess size caused by the opportunity to do sanity checks by using explicit extra data, or through allowing the data enough file space (data member size) to be out of valid range and thus able to be checked merely by looking at the asset in memory after loading.

  Read the article

< Previous Page | 478 479 480 481 482 483 484 485 486 487 488 489  | Next Page >