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About akaitora

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  1. akaitora

    Gaussian based Weights

    Hi. I was studying the Bloom tutorial on!Advanced-Lighting/Bloom I understand the benefits of using a Gaussian blur for achieving a Bloom effect. I understand that the author of this tutorial is using the gaussian values as weights which are used to determine how much neighboring pixels should affect the current pixel when blurred. In this tutorial, the author chooses to use the following weights, 0.227027, 0.1945946, 0.1216216, 0.054054, 0.016216 Where 0.227027 + (0.1945946*2.0) + (0.1216216 * 2.0) + (0.054054 * 2.0) + (0.016216 *2.0) comes out to about 1. The author chooses to same 4 samples to the left and right of the current pixel for a total sample count of 9 per axis. All that makes sense but what I don't understand is how to calculate the weights myself. For example, lets say I wanted a sample count of some arbitrary number like 5. With a sample count of 5, the formula would then need to be A + (B * 2.0) + (C * 2.0) + (D * 2.0) + (E * 2.0) = 1 What I want to do is figure out how to calculate the wights, A,B,C,D, and E given the sample count. Thanks!
  2. Why/When should you call DiscardResource?   What does this method buy you?  Is it essentially like the free method in C?  
  3. Hey guys! My team just released our latest creation, "Deer Hunter 2016". We managed to get featured in the iTunes, Google Play, and Amazon stores.  It is available on both iOS and Android platforms.     iTunes   Google Play   Amazon
  4. akaitora

    Corrupted Vertex Buffer

    mhagain, thanks for the solution!  That fixed it!  I didn't realized that glVertexAttribPointer required the buffer to be bound before use.  Thanks for the heads up!
  5. akaitora

    Math for Game Developers: Advanced Vectors

    Great video!  For more information on the Dot Product and its properties along with some more real world use cases, check out my article.
  6. akaitora

    Corrupted Vertex Buffer

    btw, for my Begin/End shader code,  I am doing the following     //--------------------------------------------------------------------- void ShaderFx::BeginPass() {     glUseProgram(shaderProgram);          if( !modelHasUvs )     {         GLint vertexAttribLocation = glGetAttribLocation(shaderProgram, "vertex");         glEnableVertexAttribArray(vertexAttribLocation);         glVertexAttribPointer(vertexAttribLocation, 3, GL_FLOAT, GL_FALSE, 0, 0);     }     else     {                  GLint vertexAttribLocation = glGetAttribLocation(shaderProgram, "vertex");         glEnableVertexAttribArray(vertexAttribLocation);         glVertexAttribPointer(vertexAttribLocation, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), 0);                  GLuint texCoordAttribLocation = glGetAttribLocation(shaderProgram, "uv");         glEnableVertexAttribArray(texCoordAttribLocation);         glVertexAttribPointer(texCoordAttribLocation, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (const GLvoid*)(3 * sizeof(GLfloat)));              } }   //--------------------------------------------------------------------- void ShaderFx::EndPass() {     GLint vertexAttribLocation = glGetAttribLocation(shaderProgram, "vertex");     GLuint texCoordAttribLocation = glGetAttribLocation(shaderProgram, "uv");          glDisableVertexAttribArray(vertexAttribLocation);     glDisableVertexAttribArray(texCoordAttribLocation); }  
  7. akaitora

    Corrupted Vertex Buffer

    Good catch!  Unfortunately I forgot to mention that I am handing the shader for the QuadGeom in a higher level class like so.     void onRenderImage(ApplicationContext &context) {     glClearColor(0.0, 0.3, 0, 1);     glEnable(GL_DEPTH_TEST);          glViewport(0, 0, context.ResolutionWidth, context.ResolutionHeight);     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);          context.ShaderFx->BeginPass();          context.ShaderFx->SetVector2Parameter("resolution", context.ResolutionWidth, context.ResolutionHeight);          context.ShaderFx->SetFloatParameter("time", context.TimeInSecondsSinceStartup);               float mouseX = (float)((context.MouseX - context.WindowPosX)) / context.ResolutionWidth;     float mouseY = (float)(-(context.MouseY - context.WindowPosY)) / context.ResolutionHeight;          context.ShaderFx->SetVector2Parameter("mouse", mouseX, mouseY);          context.QuadGeo->Render();          context.ShaderFx->EndPass();          glDisable(GL_DEPTH_TEST);     context.DisplayText->DrawString("", 0, 0); }     Any other ideas?  Thanks!
  8. Hi!  I am  trying to render 2 vertex buffers.  Each is setup a bit different.  The first only has positions whereas the second has both positions and uv coordinates.  If I only try to render one, the one I render looks great.  It doesn't matter which I render.  But if I render both together,  both vertex buffer become corrupt.  On screen, they both look like triangles even though they are suppose to be quads.  When I try making both use the same vertex format,  (I.E. verts and uvs) they render correctly.  This almost makes me think that they are somehow referencing each other somehow which is breaking the stride.  I am not explicitly unbinding my VBOs.  According to the OpenGL docs, I shouldn't need to.  However even when I do, it causes a crash.  Below are the classes for the 2 VBOs in question.   #include "QuadGeometry.h"   #include <iostream> using namespace std;   const float QuadGeometry::verts[] = {     -1.0f, 1.0f, 0.0f,     -1.0f, -1.0f, 0.0f,     1.0f, -1.0f, 0.0f,     -1.0f, 1.0f, 0.0f,     1.0, 1.0, 0.0f };   //--------------------------------------------------------------------- void QuadGeometry::Initialize() {     glGenBuffers(1, &vertexBuffer);     glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);     glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW); }   //--------------------------------------------------------------------- void QuadGeometry::Render() {     glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);     glDrawArrays(GL_TRIANGLE_STRIP, 0, 5); }     //--------------------------------------------------------------------- DisplayText::DisplayText() {     shaderFx = new ShaderFx();     shaderFx->Load( "shaders/font/vertex.glsl", "shaders/font/fragment.glsl", true );          vertexBuffer = 0;          textureSurface = nullptr;     textureSurface = SDL_LoadBMP("assets/textures/ddrsmall.bmp");     if( !textureSurface )     {         cout<< "Failed to Load Texture!\n";     }          /*     glGenTextures(1, &textureId);     glBindTexture(GL_TEXTURE_2D, textureId);          glTexImage2D(GL_TEXTURE_2D , 0 , 3 , textureSurface->w,                  textureSurface->h , 0 , GL_RGB , GL_UNSIGNED_BYTE ,                  textureSurface->pixels);          glTexParameteri(GL_TEXTURE_2D , GL_TEXTURE_MIN_FILTER , GL_LINEAR);     glTexParameteri(GL_TEXTURE_2D , GL_TEXTURE_MAG_FILTER , GL_LINEAR);     */ }   //--------------------------------------------------------------------- void DisplayText::CreateNewVertexBuffer() {     float verts[] =     {         //x    //y    //z   //u   //v         -1.0f,  1.0f,  0.0f, 0.0,  1.0,         -1.0f, -1.0f,  0.0f, 0.0,  0.0,          1.0f, -1.0f,  0.0f, 1.0,  0.0,         -1.0f,  1.0f,  0.0f, 0.0,  1.0,          1.0f,  1.0f,  0.0f, 1.0,  1.0     };          glGenBuffers(1, &vertexBuffer);     glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);     glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_DRAW); }     //--------------------------------------------------------------------- void DisplayText::DrawString(std::string string, int x, int y) {     if( vertexBuffer <= 0 )     {         CreateNewVertexBuffer();     }          shaderFx->BeginPass();          glm::mat4 Projection = glm::perspective(45.0f, 800.0f/600.0f, 0.1f, 1000.f);     glm::mat4 View = glm::translate(glm::mat4(1.0f), glm::vec3(0.0f, 0.0f, -7.0f));     glm::mat4 Model = glm::scale(glm::mat4(1.0f), glm::vec3(1.0f));     glm::mat4 modelViewMat = View * Model;          shaderFx->SetMatrix4x4Parameter("modelViewMatrix", &modelViewMat[0][0]);     shaderFx->SetMatrix4x4Parameter("projectionMatrix", &Projection[0][0]);          glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer);     glDrawArrays(GL_TRIANGLE_STRIP, 0, 5);          shaderFx->EndPass();          oldString = string; }   Any ideas would be helpful!  Thanks!
  9. Tonight I wrote a tutorial explaining how to procedurally generate noise in a shader if you need to.   Take a look here.   I hope it helps someone!  =)    
  10. A short article tI wrote that attempts to give a little insight into how this is done mathematically.  
  11. akaitora

    Roughness in a Reflection

    So if I understand correctly, from a shader perspective, we sample a cubemap just like we would as normal.  The only difference is that the cubemap is been blurred offline. Perhaps we have multiple versions of the blur per mip map.  
  12. I came across this site   And I want to write a shader that uses a cubemap for reflection but I want to take into account the roughness of the reflection.  Essentially it looks like the roughness more or less blurs the texture.  This model seems to be used in Physically based shaders.  I am curious if anyone can point me to an article that explains the formula for adding roughness to augment a reflection vector in a shader.  Thanks!
  13. akaitora

    Procedural Lightning

    Hey renman29!  That is very kind of you to say and I am glad you liked it!   I actually just made a few small adjustments to make more of a dynamic looking energy field.  It uses 2 passes of fractional brownian motion.
  14. Hey guys!  Here is a shader I wrote that demonstrates a simple way to do procedural lightning.     You will need a WebGL enabled browser to view the demo.  
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