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  • glsl shader to allow color change of skydome ogre3d

    - by Tim
    I'm still very new to all this but learning a lot. I'm putting together an application using Ogre3d as the rendering engine. So far I've got it running, with a simple scene, a day/night cycle system which is working okay. I'm now moving on to looking at changing the color of the skydome material based on the time of day. What I've done so far is to create a struct to hold the ColourValues for the different aspects of the scene. struct todColors { Ogre::ColourValue sky; Ogre::ColourValue ambient; Ogre::ColourValue sun; }; I created an array to store all the colours todColors sceneColours [4]; I populated the array with the colours I want to use for the various times of the day. For instance DayTime (when the sun is high in the sky) sceneColours[2].sky = Ogre::ColourValue(135/255, 206/255, 235/255, 255); sceneColours[2].ambient = Ogre::ColourValue(135/255, 206/255, 235/255, 255); sceneColours[2].sun = Ogre::ColourValue(135/255, 206/255, 235/255, 255); I've got code to work out the time of the day using a float currentHours to store the current hour of the day 10.5 = 10:30 am. This updates constantly and updates the sun as required. I am then calculating the appropriate colours for the time of day when relevant using else if( currentHour >= 4 && currentHour < 7) { // Lerp from night to morning Ogre::ColourValue lerp = Ogre::Math::lerp<Ogre::ColourValue, float>(sceneColours[GT_TOD_NIGHT].sky , sceneColours[GT_TOD_MORNING].sky, (currentHour - 4) / (7 - 4)); } My original attempt to get this to work was to dynamically generate a material with the new colour and apply that material to the skydome. This, as you can probably guess... didn't go well. I know it's possible to use shaders where you can pass information such as colour to the shader from the code but I am unsure if there is an existing simple shader to change a colour like this or if I need to create one. What is involved in creating a shader and material definition that would allow me to change the colour of a material without the overheads of dynamically generating materials all the time? EDIT : I've created a glsl vertex and fragment shaders as follows. Vertex uniform vec4 newColor; void main() { gl_FrontColor = newColor; gl_Position = ftransform(); } Fragment void main() { gl_FragColor = gl_Color; } I can pass a colour to it using ShaderDesigner and it seems to work. I now need to investigate how to use it within Ogre as a material. EDIT : I created a material file like this : vertex_program colour_vs_test glsl { source test.vert default_params { param_named newColor float4 0.0 0.0 0.0 1 } } fragment_program colour_fs_glsl glsl { source test.frag } material Test/SkyColor { technique { pass { lighting off fragment_program_ref colour_fs_glsl { } vertex_program_ref colour_vs_test { } } } } In the code I have tried : Ogre::MaterialPtr material = Ogre::MaterialManager::getSingleton().getByName("Test/SkyColor"); Ogre::GpuProgramParametersSharedPtr params = material->getTechnique(0)->getPass(0)->getVertexProgramParameters(); params->setNamedConstant("newcolor", Ogre::Vector4(0.7, 0.5, 0.3, 1)); I've set that as the Skydome material which seems to work initially. I am doing the same with the code that is attempting to lerp between colours, but when I include it there, it all goes black. Seems like there is now a problem with my colour lerping.

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  • Help understand GLSL directional light on iOS (left handed coord system)

    - by Robse
    I now have changed from GLKBaseEffect to a own shader implementation. I have a shader management, which compiles and applies a shader to the right time and does some shader setup like lights. Please have a look at my vertex shader code. Now, light direction should be provided in eye space, but I think there is something I don't get right. After I setup my view with camera I save a lightMatrix to transform the light from global space to eye space. My modelview and projection setup: - (void)setupViewWithWidth:(int)width height:(int)height camera:(N3DCamera *)aCamera { aCamera.aspect = (float)width / (float)height; float aspect = aCamera.aspect; float far = aCamera.far; float near = aCamera.near; float vFOV = aCamera.fieldOfView; float top = near * tanf(M_PI * vFOV / 360.0f); float bottom = -top; float right = aspect * top; float left = -right; // projection GLKMatrixStackLoadMatrix4(projectionStack, GLKMatrix4MakeFrustum(left, right, bottom, top, near, far)); // identity modelview GLKMatrixStackLoadMatrix4(modelviewStack, GLKMatrix4Identity); // switch to left handed coord system (forward = z+) GLKMatrixStackMultiplyMatrix4(modelviewStack, GLKMatrix4MakeScale(1, 1, -1)); // transform camera GLKMatrixStackMultiplyMatrix4(modelviewStack, GLKMatrix4MakeWithMatrix3(GLKMatrix3Transpose(aCamera.orientation))); GLKMatrixStackTranslate(modelviewStack, -aCamera.position.x, -aCamera.position.y, -aCamera.position.z); } - (GLKMatrix4)modelviewMatrix { return GLKMatrixStackGetMatrix4(modelviewStack); } - (GLKMatrix4)projectionMatrix { return GLKMatrixStackGetMatrix4(projectionStack); } - (GLKMatrix4)modelviewProjectionMatrix { return GLKMatrix4Multiply([self projectionMatrix], [self modelviewMatrix]); } - (GLKMatrix3)normalMatrix { return GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3([self modelviewProjectionMatrix]), NULL); } After that, I save the lightMatrix like this: [self.renderer setupViewWithWidth:view.drawableWidth height:view.drawableHeight camera:self.camera]; self.lightMatrix = [self.renderer modelviewProjectionMatrix]; And just before I render a 3d entity of the scene graph, I setup the light config for its shader with the lightMatrix like this: - (N3DLight)transformedLight:(N3DLight)light transformation:(GLKMatrix4)matrix { N3DLight transformedLight = N3DLightMakeDisabled(); if (N3DLightIsDirectional(light)) { GLKVector3 direction = GLKVector3MakeWithArray(GLKMatrix4MultiplyVector4(matrix, light.position).v); direction = GLKVector3Negate(direction); // HACK -> TODO: get lightMatrix right! transformedLight = N3DLightMakeDirectional(direction, light.diffuse, light.specular); } else { ... } return transformedLight; } You see the line, where I negate the direction!? I can't explain why I need to do that, but if I do, the lights are correct as far as I can tell. Please help me, to get rid of the hack. I'am scared that this has something to do, with my switch to left handed coord system. My vertex shader looks like this: attribute highp vec4 inPosition; attribute lowp vec4 inNormal; ... uniform highp mat4 MVP; uniform highp mat4 MV; uniform lowp mat3 N; uniform lowp vec4 constantColor; uniform lowp vec4 ambient; uniform lowp vec4 light0Position; uniform lowp vec4 light0Diffuse; uniform lowp vec4 light0Specular; varying lowp vec4 vColor; varying lowp vec3 vTexCoord0; vec4 calcDirectional(vec3 dir, vec4 diffuse, vec4 specular, vec3 normal) { float NdotL = max(dot(normal, dir), 0.0); return NdotL * diffuse; } ... vec4 calcLight(vec4 pos, vec4 diffuse, vec4 specular, vec3 normal) { if (pos.w == 0.0) { // Directional Light return calcDirectional(normalize(pos.xyz), diffuse, specular, normal); } else { ... } } void main(void) { // position highp vec4 position = MVP * inPosition; gl_Position = position; // normal lowp vec3 normal = inNormal.xyz / inNormal.w; normal = N * normal; normal = normalize(normal); // colors vColor = constantColor * ambient; // add lights vColor += calcLight(light0Position, light0Diffuse, light0Specular, normal); ... }

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  • Why do my pyramids fade black and then back to colour again

    - by geminiCoder
    I have the following vertecies and norms GLfloat verts[36] = { -0.5, 0, 0.5, 0, 0, -0.5, 0.5, 0, 0.5, 0, 0, -0.5, 0.5, 0, 0.5, 0, 1, 0, -0.5, 0, 0.5, 0, 0, -0.5, 0, 1, 0, 0.5, 0, 0.5, -0.5, 0, 0.5, 0, 1, 0 }; GLfloat norms[36] = { 0, -1, 0, 0, -1, 0, 0, -1, 0, -1, 0.25, 0.5, -1, 0.25, 0.5, -1, 0.25, 0.5, 1, 0.25, -0.5, 1, 0.25, -0.5, 1, 0.25, -0.5, 0, -0.5, -1, 0, -0.5, -1, 0, -0.5, -1 }; I am writing my fists Open GL game, But I need to know for sure if my Normals are correct as the colours aren't rendering correctly. my Pyramids are coloured then fade to black every half rotation then back again. My app so far is based on the boiler plate code provided by apple. heres my modified setUp Method [EAGLContext setCurrentContext:self.context]; [self loadShaders]; self.effect = [[GLKBaseEffect alloc] init]; self.effect.light0.enabled = GL_TRUE; self.effect.light0.diffuseColor = GLKVector4Make(1.0f, 0.4f, 0.4f, 1.0f); glEnable(GL_DEPTH_TEST); glGenVertexArraysOES(1, &_vertexArray); //create vertex array glBindVertexArrayOES(_vertexArray); glGenBuffers(1, &_vertexBuffer); glBindBuffer(GL_ARRAY_BUFFER, _vertexBuffer); glBufferData(GL_ARRAY_BUFFER, sizeof(verts) + sizeof(norms), NULL, GL_STATIC_DRAW); //create vertex buffer big enough for both verts and norms and pass NULL as data.. uint8_t *ptr = (uint8_t *)glMapBufferOES(GL_ARRAY_BUFFER, GL_WRITE_ONLY_OES); //map buffer to pass data to it memcpy(ptr, verts, sizeof(verts)); //copy verts memcpy(ptr+sizeof(verts), norms, sizeof(norms)); //copy norms to position after verts glUnmapBufferOES(GL_ARRAY_BUFFER); glEnableVertexAttribArray(GLKVertexAttribPosition); glVertexAttribPointer(GLKVertexAttribPosition, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(0)); //tell GL where verts are in buffer glEnableVertexAttribArray(GLKVertexAttribNormal); glVertexAttribPointer(GLKVertexAttribNormal, 3, GL_FLOAT, GL_FALSE, 0, BUFFER_OFFSET(sizeof(verts))); //tell GL where norms are in buffer glBindVertexArrayOES(0); And the update method. - (void)update { float aspect = fabsf(self.view.bounds.size.width / self.view.bounds.size.height); GLKMatrix4 projectionMatrix = GLKMatrix4MakePerspective(GLKMathDegreesToRadians(65.0f), aspect, 0.1f, 100.0f); self.effect.transform.projectionMatrix = projectionMatrix; GLKMatrix4 baseModelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -4.0f); baseModelViewMatrix = GLKMatrix4Rotate(baseModelViewMatrix, _rotation, 0.0f, 1.0f, 0.0f); // Compute the model view matrix for the object rendered with GLKit GLKMatrix4 modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, -1.5f); modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, _rotation, 1.0f, 1.0f, 1.0f); modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix); self.effect.transform.modelviewMatrix = modelViewMatrix; // Compute the model view matrix for the object rendered with ES2 modelViewMatrix = GLKMatrix4MakeTranslation(0.0f, 0.0f, 1.5f); modelViewMatrix = GLKMatrix4Rotate(modelViewMatrix, _rotation, 1.0f, 1.0f, 1.0f); modelViewMatrix = GLKMatrix4Multiply(baseModelViewMatrix, modelViewMatrix); _normalMatrix = GLKMatrix3InvertAndTranspose(GLKMatrix4GetMatrix3(modelViewMatrix), NULL); _modelViewProjectionMatrix = GLKMatrix4Multiply(projectionMatrix, modelViewMatrix); _rotation += self.timeSinceLastUpdate * 0.5f; } But providing I understand this correct one pyramid is using the GLKit base effect shaders and the other the shaders which are included in the project. So for both of them to have the same error, I thought it would be the Norms?

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  • How to get this wavefront .obj data onto the frustum?

    - by NoobScratcher
    I've finally figured out how to get the data from a .obj file and store the vertex positions x,y,z into a structure called Points with members x y z which are of type float. I want to know how to get this data onto the screen. Here is my attempt at doing so: //make a fileobject and store list and the index of that list in a c string ifstream file (list[index].c_str() ); std::vector<int>faces; std::vector<Point>points; points.push_back(Point()); Point p; int face[4]; while ( !file.eof() ) { char modelbuffer[10000]; //Get lines and store it in line string file.getline(modelbuffer, 10000); switch(modelbuffer[0]) { case 'v' : sscanf(modelbuffer, "v %f %f %f", &p.x, &p.y, &p.z); points.push_back(p); cout << "Getting Vertex Positions" << endl; cout << "v" << p.x << endl; cout << "v" << p.y << endl; cout << "v" << p.z << endl; break; case 'f': sscanf(modelbuffer, "f %d %d %d %d", face, face+1, face+2, face+3 ); cout << face[0] << endl; cout << face[1] << endl; cout << face[2] << endl; cout << face[3] << endl; faces.push_back(face[0]); faces.push_back(face[1]); faces.push_back(face[2]); faces.push_back(face[3]); } GLuint vertexbuffer; glGenBuffers(1, &vertexbuffer); glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer); glBufferData(GL_ARRAY_BUFFER, points.size(), points.data(), GL_STATIC_DRAW); //glBufferData(GL_ARRAY_BUFFER,sizeof(points), &(points[0]), GL_STATIC_DRAW); glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 0, 0); glVertexPointer(3, GL_FLOAT, sizeof(points),points.data()); glIndexPointer(GL_DOUBLE, 0, faces.data()); glDrawArrays(GL_QUADS, 0, points.size()); glDrawElements(GL_QUADS, faces.size(), GL_UNSIGNED_INT, faces.data()); } As you can see I've clearly failed the end part but I really don't know why its not rendering the data onto the frustum? Does anyone have a solution for this?

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  • error C2146: syntax error : missing ';' before identifier 'vertices'

    - by numerical25
    I would usually search for this error. But in VS C++ Express, this error comes up for just about every mistake you do. Any how I recieve this error below error C2146: syntax error : missing ';' before identifier 'vertices' everytime I add the following code at the top of my document // Create vertex buffer SimpleVertex vertices[] = { D3DXVECTOR3( 0.0f, 0.5f, 0.5f ), D3DXVECTOR3( 0.5f, -0.5f, 0.5f ), D3DXVECTOR3( -0.5f, -0.5f, 0.5f ), }; below is the code in it's entirety. Cant figure out whats wrong. thanks // include the basic windows header file #include "D3Dapp.h" class MyGame: public D3Dapp { public: bool Init3d(); }; MyGame game; // Create vertex buffer SimpleVertex vertices[] = { D3DXVECTOR3( 0.0f, 0.5f, 0.5f ), D3DXVECTOR3( 0.5f, -0.5f, 0.5f ), D3DXVECTOR3( -0.5f, -0.5f, 0.5f ), }; // the entry point for any Windows program int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { game.InitWindow(hInstance , nCmdShow); return game.Run(); } bool MyGame::Init3d() { D3Dapp::Init3d(); return true; }

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  • iPod/iPhone OpenGL ES UIView flashes when updating

    - by Dave Viner
    I have a simple iPhone application which uses OpenGL ES (v1) to draw a line based on the touches of the user. In the XCode Simulator, the code works perfectly. However, when I install the app onto an iPod or iPhone, the OpenGL ES view "flashes" when drawing the line. If I disable the line drawing, the flash disappears. By "flash", I mean that the background image (which is an OpenGL texture) disappears momentarily, and then reappears. It appears as if the entire scene is completely erased and redrawn. The code which handles the line drawing is the following: renderLineFromPoint:(CGPoint)start toPoint:(CGPoint)end { static GLfloat* vertexBuffer = NULL; static NSUInteger vertexMax = 64; NSUInteger vertexCount = 0, count, i; //Allocate vertex array buffer if(vertexBuffer == NULL) vertexBuffer = malloc(vertexMax * 2 * sizeof(GLfloat)); //Add points to the buffer so there are drawing points every X pixels count = MAX(ceilf(sqrtf((end.x - start.x) * (end.x - start.x) + (end.y - start.y) * (end.y - start.y)) / kBrushPixelStep), 1); for(i = 0; i < count; ++i) { if(vertexCount == vertexMax) { vertexMax = 2 * vertexMax; vertexBuffer = realloc(vertexBuffer, vertexMax * 2 * sizeof(GLfloat)); } vertexBuffer[2 * vertexCount + 0] = start.x + (end.x - start.x) * ((GLfloat)i / (GLfloat)count); vertexBuffer[2 * vertexCount + 1] = start.y + (end.y - start.y) * ((GLfloat)i / (GLfloat)count); vertexCount += 1; } //Render the vertex array glVertexPointer(2, GL_FLOAT, 0, vertexBuffer); glDrawArrays(GL_POINTS, 0, vertexCount); //Display the buffer [context presentRenderbuffer:GL_RENDERBUFFER_OES]; } (This function is based on the function of the same name from the GLPaint sample application.) For the life of me, I can not figure out why this causes the screen to flash. The line is drawn properly (both in the Simulator and in the iPod). But, the flash makes it unusable. Anyone have ideas on how to prevent the "flash"?

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  • OpenGL-ES: Change (multiply) color when using color arrays?

    - by arberg
    Following the ideas in OpenGL ES iPhone - drawing anti aliased lines, I am trying to draw stroked anti-aliased lines and I am successful so far. After line is draw by the finger, I wish to fade the path, that is I need to change the opacity (color) of the entire path. I have computed a large array of vertex positions, vertex colors, texture coordinates, and indices and then I give these to opengl but I would like reduce the opacity of all the drawn triangles without having to change each of the color coordinates. Normally I would use glColor4f(r,g,b,a) before calling drawElements, but it has no effect due to the color array. I am working on Android, but I believe it shouldn't make the big difference, as long as it is OpenGL-ES 1.1 (or 1.0). I have the following code : gl.glEnable(GL10.GL_BLEND); gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA); gl.glEnableClientState(GL10.GL_COLOR_ARRAY); gl.glShadeModel(GL10.GL_SMOOTH); gl.glEnableClientState(GL10.GL_VERTEX_ARRAY); gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY); gl.glEnable(GL10.GL_TEXTURE_2D); // Should set rgb to greyish, and alpha to half-transparent, the greyish is // just there to make the question more general its the alpha i'm interested in gl.glColor4f(.75f, .75f, .75f, 0.5f); gl.glVertexPointer(mVertexSize, GL10.GL_FLOAT, 0, mVertexBuffer); gl.glColorPointer(4, GL10.GL_FLOAT, 0, mColorBuffer); gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, mTexCoordBuffer); gl.glDrawElements(GL10.GL_TRIANGLES, indexCount, GL10.GL_UNSIGNED_SHORT, mIndexBuffer.position(startIndex)); If I disable the color array gl.glEnableClientState(GL10.GL_COLOR_ARRAY);, then the glColor4f works, if I enable the color array it does nothing. Is there any way in OpenGl-ES to change the coloring without changing all the color coordinates? I think that in OpenGl one might use a fragment shader, but it seems OpenGL does not have a fragment shader (not that I know how to use one).

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  • Optimized 2D Tile Scrolling in OpenGL

    - by silicus
    Hello, I'm developing a 2D sidescrolling game and I need to optimize my tiling code to get a better frame rate. As of right now I'm using a texture atlas and 16x16 tiles for 480x320 screen resolution. The level scrolls in both directions, and is significantly larger than 1 screen (thousands of pixels). I use glTranslate for the actual scrolling. So far I've tried: Drawing only the on-screen tiles using glTriangles, 2 per square tile (too much overhead) Drawing the entire map as a Display List (great on a small level, way to slow on a large one) Partitioning the map into Display Lists half the size of the screen, then culling display lists (still slows down for 2-directional scrolling, overdraw is not efficient) Any advice is appreciated, but in particular I'm wondering: I've seen Vertex Arrays/VBOs suggested for this because they're dynamic. What's the best way to take advantage of this? If I simply keep 1 screen of vertices plus a bit of overdraw, I'd have to recopy the array every few frames to account for the change in relative coordinates (shift everything over and add the new rows/columns). If I use more overdraw this doesn't seem like a big win; it's like the half-screen display list idea. Does glScissor give any gain if used on a bunch of small tiles like this, be it a display list or a vertex array/VBO Would it be better just to build the level out of large textures and then use glScissor? Would losing the memory saving of tiling be an issue for mobile development if I do this (just curious, I'm currently on a PC)? This approach was mentioned here Thanks :)

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  • Creating an adjacency List for DFS

    - by user200081
    I'm having trouble creating a Depth First Search for my program. So far I have a class of edges and a class of regions. I want to store all the connected edges inside one node of my region. I can tell if something is connected by the getKey() function I have already implemented. If two edges have the same key, then they are connected. For the next region, I want to store another set of connected edges inside that region, etc etc. However, I am not fully understanding DFS and I'm having some trouble implementing it. I'm not sure when/where to call DFS again. Any help would be appreciated! class edge { private: int source, destination, length; int key; edge *next; public: getKey(){ return key; } } class region { edge *data; edge *next; region() { data = new edge(); next = NULL; } }; void runDFS(int i, edge **edge, int a) { region *head = new region(); aa[i]->visited == true;//mark the first vertex as true for(int v = 0; v < a; v++) { if(tem->edge[i].getKey() == tem->edge[v].getKey()) //if the edges of the vertex have the same root { if(head->data == NULL) { head->data = aa[i]; head->data->next == NULL; } //create an edge if(head->data) { head->data->next = aa[i]; head->data->next->next == NULL; }//if there is already a node connected to ti } if(aa[v]->visited == false) runDFS(v, edge, a); //call the DFS again } //for loop }

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  • AMD Socket FM1 A8 3870 3.0Ghz ASUS F1A75-M LE

    - by Tracy
    I am building a new computer for my wife and plan on using an: AMD socket FM1 A8 3870 3.0Ghz quad core processor ASUS f1a75-M LE motherboard Corsair xms3 8gb 1600 memory (2x4) Western Digital Caviar Blue 750gb hd OCZ Vertex 120 gb SSD Coolmax blue 700 watt psu Pioneer 24x dvdrw HEC Blitz mid tower case Windows 7 Home Premium 64 bit Are there any recommended settings that I need to pay close attention too in the BIOS? For example, both the CPU and motherboard have integrated graphics (AMD Radeon HD 6550D and HD 6000, respectively).

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  • Grub Error 18 - Solid State Drive

    - by clint
    I recently used Raw Copy to make an image of my 300gb Raptor Hd to a OCZ Vertex SSD 60GB. And When I pluged in the SSD to boot I get a Grub Error 18. I have tried to changed in the BIOS setting to LBA, Large, Auto, trying different combination's. Any advice. thanks, Clint

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  • ZFS - how to partition SSD for ZIL or L2ARC use?

    - by ewwhite
    I'm working with a Sun x4540 unit with two pools and newly-installed ZIL (OCZ Vertex 2 Pro) and L2ARC (Intel X25-M) devices. Since I need to keep these two pools in the near-term, I'd like to know how to partition these devices to serve both pools of data. I've tried format, parted and fdisk and can't quite seem to get the right combination to generate recognizable partitions for zpool add. The OS in this case is NexentaStor, but I will also need this for general OpenSolaris solutions.

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  • What is the best SSD deal available right now ?

    - by paulgreg
    What is the best 2.5" SSD deal (best performance for a reasonable price and a good size) available right now ? The question is in 'community wiki' mode, so feel free to post the "winner" below : And the winner is... : currently the OCZ Vertex. Prices: * 30GB - $149.99 * 60GB - $239.99 * 120GB - $389.00 * 250GB - $829.00 Speed: * Read: up to 270MBps * Write: up to 210MBps

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  • LWJGL Circle program create's an oval-like shape

    - by N1ghtk1n9
    I'm trying to draw a circle in LWJGL, but when I draw I try to draw it, it makes a shape that's more like an oval rather than a circle. Also, when I change my circleVertexCount 350+, the shape like flips out. I'm really not sure how the code works that creates the vertices(I have taken Geometry and I know the basic trig ratios). I haven't really found that good of tutorials on creating circles. Here's my code: public class Circles { // Setup variables private int WIDTH = 800; private int HEIGHT = 600; private String title = "Circle"; private float fXOffset; private int vbo = 0; private int vao = 0; int circleVertexCount = 300; float[] vertexData = new float[(circleVertexCount + 1) * 4]; public Circles() { setupOpenGL(); setupQuad(); while (!Display.isCloseRequested()) { loop(); adjustVertexData(); Display.update(); Display.sync(60); } Display.destroy(); } public void setupOpenGL() { try { Display.setDisplayMode(new DisplayMode(WIDTH, HEIGHT)); Display.setTitle(title); Display.create(); } catch (LWJGLException e) { e.printStackTrace(); System.exit(-1); } glClearColor(0.0f, 0.0f, 0.0f, 0.0f); } public void setupQuad() { float r = 0.1f; float x; float y; float offSetX = 0f; float offSetY = 0f; double theta = 2.0 * Math.PI; vertexData[0] = (float) Math.sin(theta / circleVertexCount) * r + offSetX; vertexData[1] = (float) Math.cos(theta / circleVertexCount) * r + offSetY; for (int i = 2; i < 400; i += 2) { double angle = theta * i / circleVertexCount; x = (float) Math.cos(angle) * r; vertexData[i] = x + offSetX; } for (int i = 3; i < 404; i += 2) { double angle = Math.PI * 2 * i / circleVertexCount; y = (float) Math.sin(angle) * r; vertexData[i] = y + offSetY; } FloatBuffer vertexBuffer = BufferUtils.createFloatBuffer(vertexData.length); vertexBuffer.put(vertexData); vertexBuffer.flip(); vao = glGenVertexArrays(); glBindVertexArray(vao); vbo = glGenBuffers(); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER,vertexBuffer, GL_STATIC_DRAW); glVertexAttribPointer(0, 2, GL_FLOAT, false, 0, 0); glBindBuffer(GL_ARRAY_BUFFER, 0); glBindVertexArray(0); } public void loop() { glClear(GL_COLOR_BUFFER_BIT); glBindVertexArray(vao); glEnableVertexAttribArray(0); glDrawArrays(GL_TRIANGLE_FAN, 0, vertexData.length / 2); glDisableVertexAttribArray(0); glBindVertexArray(0); } public static void main(String[] args) { new Circles(); } private void adjustVertexData() { float newData[] = new float[vertexData.length]; System.arraycopy(vertexData, 0, newData, 0, vertexData.length); if(Keyboard.isKeyDown(Keyboard.KEY_W)) { fXOffset += 0.05f; } else if(Keyboard.isKeyDown(Keyboard.KEY_S)) { fXOffset -= 0.05f; } for(int i = 0; i < vertexData.length; i += 2) { newData[i] += fXOffset; } FloatBuffer newDataBuffer = BufferUtils.createFloatBuffer(newData.length); newDataBuffer.put(newData); newDataBuffer.flip(); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferSubData(GL_ARRAY_BUFFER, 0, newDataBuffer); glBindBuffer(GL_ARRAY_BUFFER, 0); } } 300 Vertex Count(This is my main problem) 400 Vertex Count - I removed this image, it's bugged out, should be a tiny sliver cut out from the right, like a secant 500 Vertex Count Each 100, it removes more and more of the circle, and so on.

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  • Opengl glVertexAttrib4fv doesn't work?

    - by Naor
    This is my vertex shader: static const GLchar * vertex_shader_source[] = { "#version 430 core \n" "layout (location = 0) in vec4 offset; \n" "void main(void) \n" "{ \n" " const vec4 vertices[3] = vec4[3](vec4( 0.25, -0.25, 0.5, 1.0),\n" " vec4(-0.25, -0.25, 0.5, 1.0), \n" " vec4( 0.25, 0.25, 0.5, 1.0)); \n" " gl_Position = vertices[gl_VertexID] + offset; \n" "} \n" }; and this is what im trying to do: glUseProgram(rendering_program); GLfloat attrib[] = { (float)sin(currentTime) * 0.5f, (float)cos(currentTime) * 0.6f, 0.0f, 0.0f }; glVertexAttrib4fv(0, attrib); glDrawArrays(GL_TRIANGLES, 0, 3); currentTime - The number in seconds since the program has started. Expected result - Triangle moving around the window. Its from the SuperBible book (sixth edition), this is the full code:http://pastebin.com/xA3eCKz1 The triangle should move across the screen but it doesn't.

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  • Where are some good resources to learn Game Development with OpenGL ES 2.X

    - by Mahbubur R Aaman
    Background: From http://www.khronos.org/opengles/2_X/ OpenGL ES 2.0 combines a version of the OpenGL Shading Language for programming vertex and fragment shaders that has been adapted for embedded platforms, together with a streamlined API from OpenGL ES 1.1 that has removed any fixed functionality that can be easily replaced by shader programs, to minimize the cost and power consumption of advanced programmable graphics subsystems. Related Resources The OpenGL ES 2.0 specification, header files, and optional extension specifications The OpenGL ES 2.0 Online Manual Pages The OpenGL ES 3.0 Shading LanguageOnline Reference Pages The OpenGL ES 2.0 Quick Reference Card OpenGL ES 1.X OpenGL ES 2.0 From http://www.cocos2d-iphone.org/archives/2003 Cocos2d Version 2 released and one of primary key point noted as OpenGL ES 2.0 support From http://www.h-online.com/open/news/item/Compiz-now-supports-OpenGL-ES-2-0-1674605.html Compiz now supports OpenGL ES 2.0 My Question : Being as a Game Developer ( I have to work with several game engine Cocos2d, Unity). I need several resources to cope up with OpenGL ES 2.X for better outcome while developing games?

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  • Smooth terrain rendering

    - by __dominic
    I'm trying to render a smooth terrain with Direct3D. I've got a 50*50 grid with all y values = 0, and a set of 3D points that indicate the location on the grid and depth or height of the "valley" or "hill". I need to make the y values of the grid vertices higher or lower depending on how close they are to each 3D point. Thus, in the end I should have a smooth terrain renderer. I'm not sure at all what way I can do this. I've tried changing the height of the vertices based on the distance to each point just using this basic formula: dist = a² + b² + c² where a, b and c are the x, y, and z distance from a vertex to a 3D point. The result I get with this is not smooth at all. I'm thinking there is probably a better way. Here is a screenshot of what I've got for the moment: https://dl.dropbox.com/u/2562049/terrain.jpg

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  • Google I/O 2011: 3D Graphics on Android: Lessons learned from Google Body

    Google I/O 2011: 3D Graphics on Android: Lessons learned from Google Body Nico Weber Google originally built Google Body, a 3D application that renders the human body in incredible detail, for WebGL-capable browsers running on high-end bPCs. To bring the app to Android at a high resolution and frame rate, Nico Weber and Won Chun had a close encounter with Android's graphics stack. In this session Nico will present their findings as best practices for high-end 3D graphics using OpenGL ES 2.0 on Android. The covered topics range from getting accelerated pixels on the screen to fast resource loading, performance guidelines, texture compression, mipmapping, recommended vertex attribute formats, and shader handling. The talk also touches on related topics such as SDK vs NDK, picking, and resource loading. From: GoogleDevelopers Views: 6077 29 ratings Time: 56:09 More in Science & Technology

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  • OpenGL ES 2.0: Filtering Polygons within VBO

    - by Bunkai.Satori
    Say, I send 10 polygon pairs (one polygon pair == one 2d sprite == one rectangle == two triangles) into OpenGL ES 2.0 VBO. The 10 polygon pairs represent one animated 2D object consisting of 10 frames. The 10 frames, of course, can not be rendered all at the same time, but will be rendered in particular order to make up smooth animation. Would you have an advice, how to pick up proper polygon pair for rendering (4 vertices) inside Vertex Shader from the VBO? Creating separate VBO for each frame would end up with thousands of VBOs, which is not the right way of doing it. I use OpenGL ES 2.0, and VBOs for both Vertices and Indices.

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  • Billboard shader without distortion

    - by Nick Wiggill
    I use the standard approach to billboarding within Unity that is OK, but not ideal: transform.LookAt(camera). The problem is that this introduces distortion toward the edges of the viewport, especially as the field of view angle grows larger. This is unlike the perfect billboarding you'd see in eg. Doom when seeing an enemy from any angle and irrespective of where they are located in screen space. Obviously, there are ways to blit an image directly to the viewport, centred around a single vertex, but I'm not hot on shaders. Does anyone have any samples of this approach (GLSL if possible), or any suggestions as to why it isn't typically done this way (vs. the aforementioned quad transformation method)? EDIT: I was confused, thanks Nathan for the heads up. Of course, Causing the quads to look at the camera does not cause them to be parallel to the view plane -- which is what I need.

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  • gpgpu vs. physX for physics simulation

    - by notabene
    Hello First theoretical question. What is better (faster)? Develop your own gpgpu techniques for physics simulation (cloth, fluids, colisions...) or to use PhysX? (If i say develop i mean implement existing algorithms like navier-strokes...) I don't care about what will take more time to develop. What will be faster for end user? As i understand that physx are accelerated through PPU units in gpu, does it mean that physical simulation can run in paralel with rastarization? Are PPUs different units than unified shader units used as vertex/geometry/pixel/gpgpu shader units? And little non-theoretical question: Is physx able to do sofisticated simulation equal to lets say Autodesk's Maya fluid solver? Are there any c++ gpu accelerated physics frameworks to try? (I am interested in both physx and gpgpu, commercial engines are ok too).

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  • FBX 3ds max export, bad vertices

    - by instancedName
    I need to import model in OpenGL via Fbx SdK, and for testing purposes I created a simple box centered in the (0, 0, 0), length 3, in 3ds max. Here's the image: But when i exported it, and imported in the OpenGL it wasn't in the center. Then I exported it in ASCII format, and opened the file in Notepad, and really Z coordinates were 0, and 3. When I converted model to editable mesh and checked every vertex in 3ds max it had expected (+-1.5, +-1.5, +-1.5) coordinates. Can anyone help me with this one? I'm really stuck. I tried to change whole bunch of parameters in 3ds max export, but every time it changes Z koordinate.

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  • GLSL Atmospheric Scattering Issue

    - by mtf1200
    I am attempting to use Sean O'Neil's shaders to accomplish atmospheric scattering. For now I am just using SkyFromSpace and GroundFromSpace. The atmosphere works fine but the planet itself is just a giant dark sphere with a white blotch that follows the camera. I think the problem might rest in the "v3Attenuation" variable as when this is removed the sphere is show (albeit without scattering). Here is the vertex shader. Thanks for the time! uniform mat4 g_WorldViewProjectionMatrix; uniform mat4 g_WorldMatrix; uniform vec3 m_v3CameraPos; // The camera's current position uniform vec3 m_v3LightPos; // The direction vector to the light source uniform vec3 m_v3InvWavelength; // 1 / pow(wavelength, 4) for the red, green, and blue channels uniform float m_fCameraHeight; // The camera's current height uniform float m_fCameraHeight2; // fCameraHeight^2 uniform float m_fOuterRadius; // The outer (atmosphere) radius uniform float m_fOuterRadius2; // fOuterRadius^2 uniform float m_fInnerRadius; // The inner (planetary) radius uniform float m_fInnerRadius2; // fInnerRadius^2 uniform float m_fKrESun; // Kr * ESun uniform float m_fKmESun; // Km * ESun uniform float m_fKr4PI; // Kr * 4 * PI uniform float m_fKm4PI; // Km * 4 * PI uniform float m_fScale; // 1 / (fOuterRadius - fInnerRadius) uniform float m_fScaleDepth; // The scale depth (i.e. the altitude at which the atmosphere's average density is found) uniform float m_fScaleOverScaleDepth; // fScale / fScaleDepth attribute vec4 inPosition; vec3 v3ELightPos = vec3(g_WorldMatrix * vec4(m_v3LightPos, 1.0)); vec3 v3ECameraPos= vec3(g_WorldMatrix * vec4(m_v3CameraPos, 1.0)); const int nSamples = 2; const float fSamples = 2.0; varying vec4 color; float scale(float fCos) { float x = 1.0 - fCos; return m_fScaleDepth * exp(-0.00287 + x*(0.459 + x*(3.83 + x*(-6.80 + x*5.25)))); } void main(void) { gl_Position = g_WorldViewProjectionMatrix * inPosition; // Get the ray from the camera to the vertex and its length (which is the far point of the ray passing through the atmosphere) vec3 v3Pos = vec3(g_WorldMatrix * inPosition); vec3 v3Ray = v3Pos - v3ECameraPos; float fFar = length(v3Ray); v3Ray /= fFar; // Calculate the closest intersection of the ray with the outer atmosphere (which is the near point of the ray passing through the atmosphere) float B = 2.0 * dot(m_v3CameraPos, v3Ray); float C = m_fCameraHeight2 - m_fOuterRadius2; float fDet = max(0.0, B*B - 4.0 * C); float fNear = 0.5 * (-B - sqrt(fDet)); // Calculate the ray's starting position, then calculate its scattering offset vec3 v3Start = m_v3CameraPos + v3Ray * fNear; fFar -= fNear; float fDepth = exp((m_fInnerRadius - m_fOuterRadius) / m_fScaleDepth); float fCameraAngle = dot(-v3Ray, v3Pos) / fFar; float fLightAngle = dot(v3ELightPos, v3Pos) / fFar; float fCameraScale = scale(fCameraAngle); float fLightScale = scale(fLightAngle); float fCameraOffset = fDepth*fCameraScale; float fTemp = (fLightScale + fCameraScale); // Initialize the scattering loop variables float fSampleLength = fFar / fSamples; float fScaledLength = fSampleLength * m_fScale; vec3 v3SampleRay = v3Ray * fSampleLength; vec3 v3SamplePoint = v3Start + v3SampleRay * 0.5; // Now loop through the sample rays vec3 v3FrontColor = vec3(0.0, 0.0, 0.0); vec3 v3Attenuate; for(int i=0; i<nSamples; i++) { float fHeight = length(v3SamplePoint); float fDepth = exp(m_fScaleOverScaleDepth * (m_fInnerRadius - fHeight)); float fScatter = fDepth*fTemp - fCameraOffset; v3Attenuate = exp(-fScatter * (m_v3InvWavelength * m_fKr4PI + m_fKm4PI)); v3FrontColor += v3Attenuate * (fDepth * fScaledLength); v3SamplePoint += v3SampleRay; } vec3 first = v3FrontColor * (m_v3InvWavelength * m_fKrESun + m_fKmESun); vec3 secondary = v3Attenuate; color = vec4((first + vec3(0.25,0.25,0.25) * secondary), 1.0); // ^^ that color is passed to the frag shader and is used as the gl_FragColor } Here is also an image of the problem image

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  • Atmospheric Scattering

    - by Lawrence Kok
    I'm trying to implement atmospheric scattering based on Sean O`Neil algorithm that was published in GPU Gems 2. But I have some trouble getting the shader to work. My latest attempts resulted in: http://img253.imageshack.us/g/scattering01.png/ I've downloaded sample code of O`Neil from: http://http.download.nvidia.com/developer/GPU_Gems_2/CD/Index.html. Made minor adjustments to the shader 'SkyFromAtmosphere' that would allow it to run in AMD RenderMonkey. In the images it is see-able a form of banding occurs, getting an blueish tone. However it is only applied to one half of the sphere, the other half is completely black. Also the banding appears to occur at Zenith instead of Horizon, and for a reason I managed to get pac-man shape. I would appreciate it if somebody could show me what I'm doing wrong. Vertex Shader: uniform mat4 matView; uniform vec4 view_position; uniform vec3 v3LightPos; const int nSamples = 3; const float fSamples = 3.0; const vec3 Wavelength = vec3(0.650,0.570,0.475); const vec3 v3InvWavelength = 1.0f / vec3( Wavelength.x * Wavelength.x * Wavelength.x * Wavelength.x, Wavelength.y * Wavelength.y * Wavelength.y * Wavelength.y, Wavelength.z * Wavelength.z * Wavelength.z * Wavelength.z); const float fInnerRadius = 10; const float fOuterRadius = fInnerRadius * 1.025; const float fInnerRadius2 = fInnerRadius * fInnerRadius; const float fOuterRadius2 = fOuterRadius * fOuterRadius; const float fScale = 1.0 / (fOuterRadius - fInnerRadius); const float fScaleDepth = 0.25; const float fScaleOverScaleDepth = fScale / fScaleDepth; const vec3 v3CameraPos = vec3(0.0, fInnerRadius * 1.015, 0.0); const float fCameraHeight = length(v3CameraPos); const float fCameraHeight2 = fCameraHeight * fCameraHeight; const float fm_ESun = 150.0; const float fm_Kr = 0.0025; const float fm_Km = 0.0010; const float fKrESun = fm_Kr * fm_ESun; const float fKmESun = fm_Km * fm_ESun; const float fKr4PI = fm_Kr * 4 * 3.141592653; const float fKm4PI = fm_Km * 4 * 3.141592653; varying vec3 v3Direction; varying vec4 c0, c1; float scale(float fCos) { float x = 1.0 - fCos; return fScaleDepth * exp(-0.00287 + x*(0.459 + x*(3.83 + x*(-6.80 + x*5.25)))); } void main( void ) { // Get the ray from the camera to the vertex, and its length (which is the far point of the ray passing through the atmosphere) vec3 v3FrontColor = vec3(0.0, 0.0, 0.0); vec3 v3Pos = normalize(gl_Vertex.xyz) * fOuterRadius; vec3 v3Ray = v3CameraPos - v3Pos; float fFar = length(v3Ray); v3Ray = normalize(v3Ray); // Calculate the ray's starting position, then calculate its scattering offset vec3 v3Start = v3CameraPos; float fHeight = length(v3Start); float fDepth = exp(fScaleOverScaleDepth * (fInnerRadius - fCameraHeight)); float fStartAngle = dot(v3Ray, v3Start) / fHeight; float fStartOffset = fDepth*scale(fStartAngle); // Initialize the scattering loop variables float fSampleLength = fFar / fSamples; float fScaledLength = fSampleLength * fScale; vec3 v3SampleRay = v3Ray * fSampleLength; vec3 v3SamplePoint = v3Start + v3SampleRay * 0.5; // Now loop through the sample rays for(int i=0; i<nSamples; i++) { float fHeight = length(v3SamplePoint); float fDepth = exp(fScaleOverScaleDepth * (fInnerRadius - fHeight)); float fLightAngle = dot(normalize(v3LightPos), v3SamplePoint) / fHeight; float fCameraAngle = dot(normalize(v3Ray), v3SamplePoint) / fHeight; float fScatter = (-fStartOffset + fDepth*( scale(fLightAngle) - scale(fCameraAngle)))/* 0.25f*/; vec3 v3Attenuate = exp(-fScatter * (v3InvWavelength * fKr4PI + fKm4PI)); v3FrontColor += v3Attenuate * (fDepth * fScaledLength); v3SamplePoint += v3SampleRay; } // Finally, scale the Mie and Rayleigh colors and set up the varying variables for the pixel shader vec4 newPos = vec4( (gl_Vertex.xyz + view_position.xyz), 1.0); gl_Position = gl_ModelViewProjectionMatrix * vec4(newPos.xyz, 1.0); gl_Position.z = gl_Position.w * 0.99999; c1 = vec4(v3FrontColor * fKmESun, 1.0); c0 = vec4(v3FrontColor * (v3InvWavelength * fKrESun), 1.0); v3Direction = v3CameraPos - v3Pos; } Fragment Shader: uniform vec3 v3LightPos; varying vec3 v3Direction; varying vec4 c0; varying vec4 c1; const float g =-0.90f; const float g2 = g * g; const float Exposure =2; void main(void){ float fCos = dot(normalize(v3LightPos), v3Direction) / length(v3Direction); float fMiePhase = 1.5 * ((1.0 - g2) / (2.0 + g2)) * (1.0 + fCos*fCos) / pow(1.0 + g2 - 2.0*g*fCos, 1.5); gl_FragColor = c0 + fMiePhase * c1; gl_FragColor.a = 1.0; }

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