Search Results

Search found 16410 results on 657 pages for 'game component'.

Page 317/657 | < Previous Page | 313 314 315 316 317 318 319 320 321 322 323 324  | Next Page >

• 2D Tile Map for Platformer, XML or SQLite?

  - by Stephen Tierney

  I'm developing a 2D platformer with some uni friends. We've based it upon the XNA Platformer Starter Kit which uses .txt files to store the tile map. While this is simple it does not give us enough control and flexibility with level design. I'm doing some research into whether to store level data in an XML file or in a database like SQLite. Which would be the best for this situation? Do either have any drawbacks (performance etc) compared to the other?

  Read the article

• how to retain the animated position in opengl es 2.0

  - by Arun AC

  I am doing frame based animation for 300 frames in opengl es 2.0 I want a rectangle to translate by +200 pixels in X axis and also scaled up by double (2 units) in the first 100 frames Then, the animated rectangle has to stay there for the next 100 frames. Then, I want the same animated rectangle to translate by +200 pixels in X axis and also scaled down by half (0.5 units) in the last 100 frames. I am using simple linear interpolation to calculate the delta-animation value for each frame. Pseudo code: The below drawFrame() is executed for 300 times (300 frames) in a loop. float RectMVMatrix[4][4] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 }; // identity matrix int totalframes = 300; float translate-delta; // interpolated translation value for each frame float scale-delta; // interpolated scale value for each frame // The usual code for draw is: void drawFrame(int iCurrentFrame) { // mySetIdentity(RectMVMatrix); // comment this line to retain the animated position. mytranslate(RectMVMatrix, translate-delta, X_AXIS); // to translate the mv matrix in x axis by translate-delta value myscale(RectMVMatrix, scale-delta); // to scale the mv matrix by scale-delta value ... // opengl calls glDrawArrays(...); eglswapbuffers(...); } The above code will work fine for first 100 frames. in order to retain the animated rectangle during the frames 101 to 200, i removed the "mySetIdentity(RectMVMatrix);" in the above drawFrame(). Now on entering the drawFrame() for the 2nd frame, the RectMVMatrix will have the animated value of first frame e.g. RectMVMatrix[4][4] = { 1.01, 0, 0, 2, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1 };// 2 pixels translation and 1.01 units scaling after first frame This RectMVMatrix is used for mytranslate() in 2nd frame. The translate function will affect the value of "RectMVMatrix[0][0]". Thus translation affects the scaling values also. Eventually output is getting wrong. How to retain the animated position without affecting the current ModelView matrix? =========================================== I got the solution... Thanks to Sergio. I created separate matrices for translation and scaling. e.g.CurrentTranslateMatrix[4][4], CurrentScaleMatrix[4][4]. Then for every frame, I reset 'CurrentTranslateMatrix' to identity and call mytranslate( CurrentTranslateMatrix, translate-delta, X_AXIS) function. I reset 'CurrentScaleMatrix' to identity and call myscale(CurrentScaleMatrix, scale-delta) function. Then, I multiplied these 'CurrentTranslateMatrix' and 'CurrentScaleMatrix' to get the final 'RectMVMatrix' Matrix for the frame. Pseudo Code: float RectMVMatrix[4][4] = {0}; float CurrentTranslateMatrix[4][4] = {0}; float CurrentScaleMatrix[4][4] = {0}; int iTotalFrames = 300; int iAnimationFrames = 100; int iTranslate_X = 200.0f; // in pixels float fScale_X = 2.0f; float scaleDelta; float translateDelta_X; void DrawRect(int iTotalFrames) { mySetIdentity(RectMVMatrix); for (int i = 0; i< iTotalFrames; i++) { DrawFrame(int iCurrentFrame); } } void getInterpolatedValue(int iStartFrame, int iEndFrame, int iTotalFrame, int iCurrentFrame, float *scaleDelta, float *translateDelta_X) { float fDelta = float ( (iCurrentFrame - iStartFrame) / (iEndFrame - iStartFrame)) float fStartX = 0.0f; float fEndX = ConvertPixelsToOpenGLUnit(iTranslate_X); *translateDelta_X = fStartX + fDelta * (fEndX - fStartX); float fStartScaleX = 1.0f; float fEndScaleX = fScale_X; *scaleDelta = fStartScaleX + fDelta * (fEndScaleX - fStartScaleX); } void DrawFrame(int iCurrentFrame) { getInterpolatedValue(0, iAnimationFrames, iTotalFrames, iCurrentFrame, &scaleDelta, &translateDelta_X) mySetIdentity(CurrentTranslateMatrix); myTranslate(RectMVMatrix, translateDelta_X, X_AXIS); // to translate the mv matrix in x axis by translate-delta value mySetIdentity(CurrentScaleMatrix); myScale(RectMVMatrix, scaleDelta); // to scale the mv matrix by scale-delta value myMultiplyMatrix(RectMVMatrix, CurrentTranslateMatrix, CurrentScaleMatrix);// RectMVMatrix = CurrentTranslateMatrix*CurrentScaleMatrix; ... // opengl calls glDrawArrays(...); eglswapbuffers(...); } I maintained this 'RectMVMatrix' value, if there is no animation for the current frame (e.g. 101th frame onwards). Thanks, Arun AC

  Read the article

• How can I prevent seams from showing up on objects using lower mipmap levels?

  - by Shivan Dragon

  Disclaimer: kindly right click on the images and open them separately so that they're at full size, as there are fine details which don't show up otherwise. Thank you. I made a simple Blender model, it's a cylinder with the top cap removed: I've exported the UVs: Then imported them into Photoshop, and painted the inner area in yellow and the outer area in red. I made sure I cover well the UV lines: I then save the image and load it as texture on the model in Blender. Actually, I just reload it as the image where the UVs are exported, and change the viewport view mode to textured. When I look at the mesh up-close, there's yellow everywhere, everything seems fine: However, if I start zooming out, I start seeing red (literally and metaphorically) where the texture edges are: And the more I zoom, the more I see it: Same thing happends in Unity, though the effect seems less pronounced. Up close is fine and yellow: Zoom out and you see red at the seams: Now, obviously, for this simple example a workaround is to spread the yellow well outside the UV margins, and its fine from all distances. However this is an issue when you try making a complex texture that should tile seamlessly at the edges. In this situation I either make a few lines of pixels overlap (in which case it looks bad from upclose and ok from far away), or I leave them seamless and then I have those seams when seeing it from far away. So my question is, is there something I'm missing, or some extra thing I must do to have my texture look seamless from all distances?

  Read the article

• What's the most efficient way to find barycentric coordinates?

  - by bobobobo

  In my profiler, finding barycentric coordinates is apparently somewhat of a bottleneck. I am looking to make it more efficient. It follows the method in shirley, where you compute the area of the triangles formed by embedding the point P inside the triangle. Code: Vector Triangle::getBarycentricCoordinatesAt( const Vector & P ) const { Vector bary ; // The area of a triangle is real areaABC = DOT( normal, CROSS( (b - a), (c - a) ) ) ; real areaPBC = DOT( normal, CROSS( (b - P), (c - P) ) ) ; real areaPCA = DOT( normal, CROSS( (c - P), (a - P) ) ) ; bary.x = areaPBC / areaABC ; // alpha bary.y = areaPCA / areaABC ; // beta bary.z = 1.0f - bary.x - bary.y ; // gamma return bary ; } This method works, but I'm looking for a more efficient one!

  Read the article

• Terrain sqaure loading

  - by AndroidXTr3meN

  Games like Skyrim, Morrowind, and more are using quads or sqaure to divide the terrain if im correct. The player is always at #5 1 | 2 | 3 4 | 5 | 6 7 | 8 | 9 So whenever you cross the border you unload and load the new "areas" But if the user goes just over the edge and then the second after goes back previous area a lot of uneccessary loading and unloading is done. Is there a general approach to this becuase I dont think games like skyrim have this issue? Cheers!

  Read the article

• Distance between two 3D objects' faces

  - by Arthur Gibraltar

  I'm really newbie on programming and I'm making some tests. I couldn't find nowhere on Internet how could I calculate the distance between two 3D objects' faces. Is there anyway? Detailing, as an example, I have two 3D cubes. Each one has a vector3 position designating it's center on the 3D space and an orientation matrix. And each cube has a size (float width, float height and float length). I could get a simple distance between them by calling Vector3.Distance(), but it doesn't consider its sizes, just the position. Then the distance would be between its centers. Is there any way to calculate the distance between the faces? Thanks for any reply.

  Read the article

• Java - Tile engine changing number in array not changing texture

  - by Corey

  I draw my map from a txt file. Would I have to write to the text file to notice the changes I made? Right now it changes the number in the array but the tile texture doesn't change. Do I have to do more than just change the number in the array? public class Tiles { public Image[] tiles = new Image[5]; public int[][] map = new int[64][64]; private Image grass, dirt, fence, mound; private SpriteSheet tileSheet; public int tileWidth = 32; public int tileHeight = 32; Player player = new Player(); public void init() throws IOException, SlickException { tileSheet = new SpriteSheet("assets/tiles.png", tileWidth, tileHeight); grass = tileSheet.getSprite(0, 0); dirt = tileSheet.getSprite(7, 7); fence = tileSheet.getSprite(2, 0); mound = tileSheet.getSprite(2, 6); tiles[0] = grass; tiles[1] = dirt; tiles[2] = fence; tiles[3] = mound; int x=0, y=0; BufferedReader in = new BufferedReader(new FileReader("assets/map.dat")); String line; while ((line = in.readLine()) != null) { String[] values = line.split(","); for (String str : values) { int str_int = Integer.parseInt(str); map[x][y]=str_int; //System.out.print(map[x][y] + " "); y=y+1; } //System.out.println(""); x=x+1; y = 0; } in.close(); } public void update(GameContainer gc) { } public void render(GameContainer gc) { for(int x = 0; x < map.length; x++) { for(int y = 0; y < map.length; y ++) { int textureIndex = map[y][x]; Image texture = tiles[textureIndex]; texture.draw(x*tileWidth,y*tileHeight); } } } Mouse picking public void checkDistance(GameContainer gc) { Input input = gc.getInput(); float mouseX = input.getMouseX(); float mouseY = input.getMouseY(); double mousetileX = Math.floor((double)mouseX/tiles.tileWidth); double mousetileY = Math.floor((double)mouseY/tiles.tileHeight); double playertileX = Math.floor(playerX/tiles.tileWidth); double playertileY = Math.floor(playerY/tiles.tileHeight); double lengthX = Math.abs((float)playertileX - mousetileX); double lengthY = Math.abs((float)playertileY - mousetileY); double distance = Math.sqrt((lengthX*lengthX)+(lengthY*lengthY)); if(input.isMousePressed(Input.MOUSE_LEFT_BUTTON) && distance < 4) { System.out.println("Clicked"); if(tiles.map[(int)mousetileX][(int)mousetileY] == 1) { tiles.map[(int)mousetileX][(int)mousetileY] = 0; } } System.out.println(tiles.map[(int)mousetileX][(int)mousetileY]); }

  Read the article

• Tile map collision is not working properly

  - by Sigh-AniDe

  I am having problems setting collision between my sprite and the tiles. I have only done the code for colision for moving upwards but some places on the map it moves up and some places it doesn't. Here is what I have so far: Vector2 position; private static float scalingFactor = 32; static int tileWidth = 32; static int tileHeight = 32; int[ , ] map = { {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, {0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, {0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, {0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, {0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, {0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, }, }; // This is in turtle.update if ( keyboardState.IsKeyDown( Keys.Up ) ) { if ( position.Y > screenHeight / 4 ) { //// current position of the turtle on the tiles int mapX = ( int )( position.X / scalingFactor ); int mapY = ( int )( position.Y / scalingFactor ) - 1; if ( isMovable( mapX , mapY , map ) ) { position.Y = position.Y - scalingFactor; } } else { MoveUp(); } } private void MoveUp() { motion.Y = -1; } public bool isMovable( int mapX , int mapY , int[ , ] map ) { if ( mapX < 0 || mapX > 19 || mapY < 0 || mapY > 20 ) { return false; } int tile = map[ mapX , mapY ]; if ( tile == 0 ) { return false; } return true; } protected override void Update( GameTime gameTime ) { turtle.Update( screenHeight , scalingFactor , map ); base.Update( gameTime ); }

  Read the article

• Most efficient way to implement delta time

  - by Starkers

  Here's one way to implement delta time: /// init /// var duration = 5000, currentTime = Date.now(); // and create cube, scene, camera ect ////// function animate() { /// determine delta /// var now = Date.now(), deltat = now - currentTime, currentTime = now, scalar = deltat / duration, angle = (Math.PI * 2) * scalar; ////// /// animate /// cube.rotation.y += angle; ////// /// update /// requestAnimationFrame(render); ////// } Could someone confirm I know how it works? Here what I think is going on: Firstly, we set duration at 5000, which how long the loop will take to complete in an ideal world. With a computer that is slow/busy, let's say the animation loop takes twice as long as it should, so 10000: When this happens, the scalar is set to 2.0: scalar = deltat / duration scalar = 10000 / 5000 scalar = 2.0 We now times all animation by twice as much: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 2.0; angle = (Math.PI * 4) // which is 2 rotations When we do this, the cube rotation will appear to 'jump', but this is good because the animation remains real-time. With a computer that is going too quickly, let's say the animation loop takes half as long as it should, so 2500: When this happens, the scalar is set to 0.5: scalar = deltat / duration scalar = 2500 / 5000 scalar = 0.5 We now times all animation by a half: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 0.5; angle = (Math.PI * 1) // which is half a rotation When we do this, the cube won't jump at all, and the animation remains real time, and doesn't speed up. However, would I be right in thinking this doesn't alter how hard the computer is working? I mean it still goes through the loop as fast as it can, and it still has render the whole scene, just with different smaller angles! So this a bad way to implement delta time, right? Now let's pretend the computer is taking exactly as long as it should, so 5000: When this happens, the scalar is set to 1.0: angle = (Math.PI * 2) * scalar; angle = (Math.PI * 2) * 1; angle = (Math.PI * 2) // which is 1 rotation When we do this, everything is timsed by 1, so nothing is changed. We'd get the same result if we weren't using delta time at all! My questions are as follows Mostly importantly, have I got the right end of the stick here? How do we know to set the duration to 5000 ? Or can it be any number? I'm a bit vague about the "computer going too quickly". Is there a way loop less often rather than reduce the animation steps? Seems like a better idea. Using this method, do all of our animations need to be timesed by the scalar? Do we have to hunt down every last one and times it? Is this the best way to implement delta time? I think not, due to the fact the computer can go nuts and all we do is divide each animation step and because we need to hunt down every step and times it by the scalar. Not a very nice DSL, as it were. So what is the best way to implement delta time? Below is one way that I do not really get but may be a better way to implement delta time. Could someone explain please? // Globals INV_MAX_FPS = 1 / 60; frameDelta = 0; clock = new THREE.Clock(); // In the animation loop (the requestAnimationFrame callback)… frameDelta += clock.getDelta(); // API: "Get the seconds passed since the last call to this method." while (frameDelta >= INV_MAX_FPS) { update(INV_MAX_FPS); // calculate physics frameDelta -= INV_MAX_FPS; } How I think this works: Firstly we set INV_MAX_FPS to 0.01666666666 How we will use this number number does not jump out at me. We then intialize a frameDelta which stores how long the last loop took to run. Come the first loop frameDelta is not greater than INV_MAX_FPS so the loop is not run (0 = 0.01666666666). So nothing happens. Now I really don't know what would cause this to happen, but let's pretend that the loop we just went through took 2 seconds to complete: We set frameDelta to 2: frameDelta += clock.getDelta(); frameDelta += 2.00 Now we run an animation thanks to update(0.01666666666). Again what is relevance of 0.01666666666?? And then we take away 0.01666666666 from the frameDelta: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 2 - 0.01666666666 frameDelta = 1.98333333334 So let's go into the second loop. Let's say it took 2(? Why not 2? Or 12? I am a bit confused): frameDelta += clock.getDelta(); frameDelta = frameDelta + clock.getDelta(); frameDelta = 1.98333333334 + 2 frameDelta = 3.98333333334 This time we enter the while loop because 3.98333333334 = 0.01666666666 We run update We take away 0.01666666666 from frameDelta again: frameDelta -= INV_MAX_FPS; frameDelta = frameDelta - INV_MAX_FPS; frameDelta = 3.98333333334 - 0.01666666666 frameDelta = 3.96666666668 Now let's pretend the loop is super quick and runs in just 0.1 seconds and continues to do this. (Because the computer isn't busy any more). Basically, the update function will be run, and every loop we take away 0.01666666666 from the frameDelta untill the frameDelta is less than 0.01666666666. And then nothing happens until the computer runs slowly again? Could someone shed some light please? Does the update() update the scalar or something like that and we still have to times everything by the scalar like in the first example?

  Read the article

• Modern Shader Book?

  - by Michael Stum

  I'm interested in learning about Shaders: What are they, when/for what would I use them, and how to use them. (Specifically I'm interested in Water and Bloom effects, but I know close to 0 about Shaders, so I need a general introduction). I saw a lot of books that are a couple of years old, so I don't know if they still apply. I'm targeting XNA 4.0 at the moment (which I believe means HLSL Shaders for Shader Model 4.0), but anything that generally targets DirectX 11 and OpenGL 4 is helpful I guess.

  Read the article

• How is this lighting effect done?

  - by Mike

  This is the most beautiful 2d lighting I have ever seen. Does anyone know how he went about doing it? http://www.youtube.com/watch?v=BIQRhOFkvQY http://www.youtube.com/watch?v=tnTYXPuecMs http://www.youtube.com/watch?v=rhC_jVM8IYU http://www.youtube.com/watch?v=_Aw5BdjWqqU Or download it here: http://grantkot.com/PollutedPlanet/publish.htm edit: I am not asking how the particles are simulated; I don't care about the physics.

  Read the article

• D3D11 how to simulate multiple depth channels

  - by Nock

  Here's what I'd like to achieve: Rendering a first pass of objects in my scene, using standard depth comparison Rendering another pass of objects in the same scene, but with the following rules: A Pixel of the 2nd pass always override the first pass (no depth compare between them) Use Depth comparison between pixels written from the second pass. In English I want depth comparison made inside each pass but I always want the second pass pixels to override the first pass ones. Some things I've thought: I tried to think about using stencil to solve this, but I couldn't find a way. I know I could render into a separate target the second pass then composite the result into the first, but I'd like to avoid that. I could use two separate Depth Buffer, one dedicated to each pass. (I never tried, but I figure it's possible to switch the depth buffer in a Render Target "on the fly") Any idea of the best solution? Thanks

  Read the article

• Stencil buffer appears to not be decrementing values correctly

  - by Alex Ames

  I'm attempting to use the stencil buffer as a clipper for my UI system, but I'm having trouble debugging a problem I'm running in to. This is what I'm doing: A widget can pass a rectangle to the the stencil clipper functions, which will increment the stencil buffer values that it covers. Then it will draw its children, which will only get drawn in the stencilled area (so that if they extend outside they'll be clipped). After a widget is done drawing its children, it pops that rectangle from the stack and in the process decrements the values in the stencil buffer that it has previously incremented. The slightly simplified code is below: static void drawStencil(Rect& rect, unsigned int ref) { // Save previous values of the color and depth masks GLboolean colorMask[4]; GLboolean depthMask; glGetBooleanv(GL_COLOR_WRITEMASK, colorMask); glGetBooleanv(GL_DEPTH_WRITEMASK, &depthMask); // Turn off drawing glColorMask(0, 0, 0, 0); glDepthMask(0); // Draw vertices here ... // Turn everything back on glColorMask(colorMask[0], colorMask[1], colorMask[2], colorMask[3]); glDepthMask(depthMask); // Only render pixels in areas where the stencil buffer value == ref glStencilFunc(GL_EQUAL, ref, 0xFF); glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP); } void pushScissor(Rect rect) { // increment things only at the current stencil stack level glStencilFunc(GL_EQUAL, s_scissorStack.size(), 0xFF); glStencilOp(GL_KEEP, GL_INCR, GL_INCR); s_scissorStack.push_back(rect); drawStencil(rect, states, s_ScissorStack.size()); } void popScissor() { // undo what was done in the previous push, // decrement things only at the current stencil stack level glStencilFunc(GL_EQUAL, s_scissorStack.size(), 0xFF); glStencilOp(GL_KEEP, GL_DECR, GL_DECR); Rect rect = s_scissorStack.back(); s_scissorStack.pop_back(); drawStencil(rect, states, s_scissorStack.size()); } And this is how it's being used by the Widgets if (m_clip) pushScissor(m_rect); drawInternal(target, states); for (auto child : m_children) target.draw(*child, states); if (m_clip) popScissor(); This is the result of the above code: There are two things on the screen, a giant test button, and a window with some buttons and text areas on it. The text area scroll box is set to clip its children (so that the text doesn't extend outside the scroll box). The button is drawn after the window and should be on top of it completely. However, for some reason the text area is appearing on top of the button. The only reason I can think of that this would happen is if the stencil values were not getting decremented in the pop, and when it comes time to render the button, since those pixels don't have the right stencil value it doesn't draw over. But I can't figure out whats wrong with my code that would cause that to happen.

  Read the article

• Most efficient AABB - Ray intersection algorithm for input/output distance calculation

  - by Tobbey

  Thanks to the following thread : most efficient AABB vs Ray collision algorithms I have seen very fast algorithm for ray/AABB intersection point computation. Unfortunately, most of the recent algorithm are accelerated by omitting the "output" intersection point of the box. In my application, I would interested in getting both the the distance from source ray to input: t0 and source ray to output of bounding box: t1. I have seen for instance Eisemann designed a very fast version regarding plucker, smits, ... , but it does not compare the case when both input/output distance should be computed see: http://www.cg.cs.tu-bs.de/publications/Eisemann07FRA/ Does someone know where I can find more information on algorithm performances for the specific input/output problem ? Thank you in advance

  Read the article

• Mapping a 3D texture to a standard hollow-hull 3D model

  - by John

  I have 3D models which are typical hollow hulls. If such a model also had a 3D volumetric/voxel texture map then given a point P inside such a model, I'd like to be able to find its uvw coordinates within the 3D texture. Is this possible by simply setting 3D texcoords on my existing mesh or does it have to be broken up into polyhedra? Is there a way to map a 3D texture onto a mesh without doing this?

  Read the article

• Sprites, Primitives and logic entity as structs

  - by Jeffrey

  I'm wondering would it be considered acceptable: The window class is responsible for drawing data, so it will have a method: Window::draw(const Sprite&); Window::draw(const Rect&); Window::draw(const Triangle&); Window::draw(const Circle&); and all those primitives + sprites would be just public struct. For example Sprite: struct Sprite { float x, y; // center float origin_x, origin_y; float width, height; float rotation; float scaling; GLuint texture; Sprite(float w, float h); Sprite(float w, float h, float a, float b); void useTexture(std::string file); void setOrigin(float a, float b); void move(float a, float b); // relative move void moveTo(float a, float b); // absolute move void rotate(float a); // relative rotation void rotateTo(float a); // absolute rotation void rotationReset(); void scale(float a); // relative scaling void scaleTo(float a); // absolute scaling void scaleReset(); }; So instead of having each primitive to call their draw() function, which is a little bit off topic for their object, I let the Window class handle all the OpenGL stuff and manipulate them as simple objects that will be drawn later on. Is this pattern used? Does it have any cons against it's primitives-draw-themself pattern? Are there any other related patterns?

  Read the article

• Using multiple indexes with buffer objects in OpenTK

  - by Rushyo

  I've got multiple buffers in OpenGL holding data on position, normals and texcoords. I also have an equal number of buffers holding distinct index data for each of those buffers. I quite like this format (indvidual indexes for each buffer) utilised by COLLADA since it strikes me as optimally efficient at accessing each buffer. I've set up pointers to the relevant data arrays using VertexPointer, NormalPointer, etc however I have no way to assign pointers to the index buffers since DrawElements appear to only look at one ElementArrayBuffer. Can I utilise multiple indices some way or will I be better off using a different technique which can support this? I'd prefer to keep the distinct indices if at all possible.

  Read the article

• Clear edged sprite

  - by Ananth

  I am a newbie to cocos2d. I would like make user to draw similar to what a painting brush would do. I am using CCSprite for that. I almost implemented the velocity, color and opacity factors for that tool, but I couldn't get the Sprite to be as clear as it should be. I can draw only in the below image http://i.imgur.com/KBe0L.png which has blunt edges. But I want it to be harder / clear outside edges as in http://i.stack.imgur.com/GrFlv.png. I am getting no idea to make it clear edged. The piece of code Im using is glEnable(GL_BLEND); [brush.texture setAliasTexParameters]; [brush setBlendFunc:(ccBlendFunc){GL_ONE, GL_ONE_MINUS_SRC_ALPHA}]; [brush visit]; I suspect the problem would be on blending mode. I tried some blending modes, but with no expected results. I am trying this for the past five days and so confused. Can some one help me sort this out? Thanks in advance.

  Read the article

• Rotate an image in a scaled context

  - by nathan

  Here is my working piece of code to rotate an image toward a point (in my case, the mouse cursor). float dx = newx - ploc.x; float dy = newy - ploc.y; float angle = (float) Math.toDegrees(Math.atan2(dy, dx)); Where ploc is the location of the image i'm rotating. And here is the rendering code: g.rotate(loc.x + width / 2, loc.y + height / 2, angle); g.drawImage(frame, loc.x, loc.y); Where loc is the location of the image and "width" and "height" are respectively the width and height of the image. What changes are needed to make it works on a scaled context? e.g make it works with something like g.scale(sx, sy).

  Read the article

• 2D metaball liquid effect - how to feed output of one rendering pass as input to another shader

  - by Guye Incognito

  I'm attempting to make a shader for unity3d web project. I want to implement something like in the great answer by DMGregory in this question. in order to achieve a final look something like this.. Its metaballs with specular and shading. The steps to make this shader are. 1. Convert the feathered blobs into a heightmap. 2. Generate a normalmap from the heightmap 3. Feed the normal map and height map into a standard unity shader, for instance transparent parallax specular. I pretty much have all the pieces I need assembled but I am new to shaders and need help putting them together I can generate a heightmap from the blobs using some fragment shader code I wrote (I'm just using the red channel here cus i dont know if you can access the brightness) half4 frag (v2f i) : COLOR{ half4 texcol,finalColor; texcol = tex2D (_MainTex, i.uv); finalColor=_MyColor; if(texcol.r<_botmcut) { finalColor.r= 0; } else if((texcol.r>_topcut)) { finalColor.r= 0; } else { float r = _topcut-_botmcut; float xpos = _topcut - texcol.r; finalColor.r= (_botmcut + sqrt((xpos*xpos)-(r*r)))/_constant; } return finalColor; } turns these blobs.. into this heightmap Also I've found some CG code that generates a normal map from a height map. The bit of code that makes the normal map from finite differences is here void surf (Input IN, inout SurfaceOutput o) { o.Albedo = fixed3(0.5); float3 normal = UnpackNormal(tex2D(_BumpMap, IN.uv_MainTex)); float me = tex2D(_HeightMap,IN.uv_MainTex).x; float n = tex2D(_HeightMap,float2(IN.uv_MainTex.x,IN.uv_MainTex.y+1.0/_HeightmapDimY)).x; float s = tex2D(_HeightMap,float2(IN.uv_MainTex.x,IN.uv_MainTex.y-1.0/_HeightmapDimY)).x; float e = tex2D(_HeightMap,float2(IN.uv_MainTex.x-1.0/_HeightmapDimX,IN.uv_MainTex.y)).x; float w = tex2D(_HeightMap,float2(IN.uv_MainTex.x+1.0/_HeightmapDimX,IN.uv_MainTex.y)).x; float3 norm = normal; float3 temp = norm; //a temporary vector that is not parallel to norm if(norm.x==1) temp.y+=0.5; else temp.x+=0.5; //form a basis with norm being one of the axes: float3 perp1 = normalize(cross(norm,temp)); float3 perp2 = normalize(cross(norm,perp1)); //use the basis to move the normal in its own space by the offset float3 normalOffset = -_HeightmapStrength * ( ( (n-me) - (s-me) ) * perp1 + ( ( e - me ) - ( w - me ) ) * perp2 ); norm += normalOffset; norm = normalize(norm); o.Normal = norm; } Also here is the built-in transparent parallax specular shader for unity. Shader "Transparent/Parallax Specular" { Properties { _Color ("Main Color", Color) = (1,1,1,1) _SpecColor ("Specular Color", Color) = (0.5, 0.5, 0.5, 0) _Shininess ("Shininess", Range (0.01, 1)) = 0.078125 _Parallax ("Height", Range (0.005, 0.08)) = 0.02 _MainTex ("Base (RGB) TransGloss (A)", 2D) = "white" {} _BumpMap ("Normalmap", 2D) = "bump" {} _ParallaxMap ("Heightmap (A)", 2D) = "black" {} } SubShader { Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"} LOD 600 CGPROGRAM #pragma surface surf BlinnPhong alpha #pragma exclude_renderers flash sampler2D _MainTex; sampler2D _BumpMap; sampler2D _ParallaxMap; fixed4 _Color; half _Shininess; float _Parallax; struct Input { float2 uv_MainTex; float2 uv_BumpMap; float3 viewDir; }; void surf (Input IN, inout SurfaceOutput o) { half h = tex2D (_ParallaxMap, IN.uv_BumpMap).w; float2 offset = ParallaxOffset (h, _Parallax, IN.viewDir); IN.uv_MainTex += offset; IN.uv_BumpMap += offset; fixed4 tex = tex2D(_MainTex, IN.uv_MainTex); o.Albedo = tex.rgb * _Color.rgb; o.Gloss = tex.a; o.Alpha = tex.a * _Color.a; o.Specular = _Shininess; o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap)); } ENDCG } FallBack "Transparent/Bumped Specular" }

  Read the article

• Tangent basis calculation problem

  - by Kirill Daybov

  I have the problem with seams with calculating a tangent basis in my application. I'm using a seems to be right algorithm, but it gives wrong result on the seams. What am I doing wrong? Is there a problem with an algorithm, or with the model? The designer says that our models with our normal maps are rendered correctly in Xoliul Shader Plugin in 3Ds Max, so there should be a way to calculate correct tangent basis programmatically. Here's an example of the problem I'm talking about. Steps, I've already taken: - Tried different algorithm (from Gamasutra, I can't post the link because I don't have enough reputation yet). I got wrong, much worse, results; - Tried to average basis vectors for vertexes are used in multiple faces; - Tried to average basis vectors for vertexes that have same world coordinates (this would be obviously wrong solution, but I've tried it anyway).

  Read the article

• How to draw texture to screen in Unity?

  - by user1306322

  I'm looking for a way to draw textures to screen in Unity in a similar fashion to XNA's SpriteBatch.Draw method. Ideally, I'd like to write a few helper methods to make all my XNA code work in Unity. This is the first issue I've faced on this seemingly long journey. I guess I could just use quads, but I'm not so sure it's the least expensive way performance-wise. I could do that stuff in XNA anyway, but they made SpriteBatch not without a reason, I believe.

  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

• Static "LoD" hack opinions

  - by David Lively

  I've been playing with implementing dynamic level of detail for rendering a very large mesh in XNA. It occurred to me that (duh) the whole point of this is to generate small triangles close to the camera, and larger ones far away. Given that, rather than constantly modifying or swapping index buffers based on a feature's rendered size or distance from the camera, it would be a lot easier (and potentially quite a bit faster), to render a single "fan" or flat wedge/frustum-shaped planar mesh that is tessellated into small triangles close to the near or small end of the frustum and larger ones at the far end, sort of like this (overhead view) (Pardon the gap in the middle - I drew one side and mirrored it) The triangle sizes are chosen so that all are approximately the same size when projected. Then, that mesh would be transformed to track the camera so that the Z axis (center vertical in this image) is always aligned with the view direction projected into the XZ plane. The vertex shader would then read terrain heights from a height texture and adjust the Y coordinate of the mesh to match a height field that defines the terrain. This eliminates the need for culling (since the mesh is generated to match the viewport dimensions) and the need to modify the index and/or vertex buffers when drawing the terrain. Obviously this doesn't address terrain with overhangs, etc, but that could be handled to a certain extent by including a second mesh that defines a sort of "ceiling" via a different texture. The other LoD schemes I've seen aren't particularly difficult to implement and, in some cases, are a lot more flexible, but this seemed like a decent quick-and-dirty way to handle height map-based terrain without getting into geometry manipulation. Has anyone tried this? Opinions?

  Read the article

• How can I make the camera return to the beginning of the terrain when it reaches the end?

  - by wbaccari

  How can I make the camera return to the beginning of the terrain when it reaches the end? I tried using the ICameraSceneNode*-setPosition(). if (camera->getPosition().X>1200.f) camera->setPosition(vector3df(1.f,1550.f,camera->getPosition().Z)); if (camera->getPosition().X<0.f) camera->setPosition(vector3df(1199.f,1550.f,camera->getPosition().Z)); if (camera->getPosition().Z>1200.f) camera->setPosition(vector3df(camera->getPosition().X,1550.f,1.f)); if (camera->getPosition().Z<0.f) camera->setPosition(vector3df(camera->getPosition().X,1550.f,1199.f)); It seems to work fine with a flat terrain (one shade of grey in heightmap) but it starts to produce a strange behavior as soon as i try to add some hills. Edit: The setPosition() call seems to perform a translation of the camera toward the new position, therefore the camera stops at the first obstacle it encounters on its way.

  Read the article

< Previous Page | 313 314 315 316 317 318 319 320 321 322 323 324  | Next Page >