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    • By racarate
      Hey everybody!
      I am trying to replicate all these cool on-screen debug visuals I see in all the SIGGRAPH and GDC talks, but I really don't know where to start.  The only resource I know of is almost 16 years old:
      http://number-none.com/product/Interactive Profiling, Part 1/index.html
      Does anybody have a more up-to-date reference?  Do people use minimal UI libraries like Dear ImgGui?  Also, If I am profiling OpenGL ES 3.0 (which doesn't have timer queries) is there really anything I can do to measure performance GPU-wise?  Or should I just chart CPU-side frame time?  I feel like this is something people re-invent for every game there has gotta be a tutorial out there... right?
       
       
    • By Achivai
      Hey, I am semi-new to 3d-programming and I've hit a snag. I have one object, let's call it Object A. This object has a long int array of 3d xyz-positions stored in it's vbo as an instanced attribute. I am using these numbers to instance object A a couple of thousand times. So far so good. 
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    • By fleissi
      Hey guys!

      I'm new here and I recently started developing my own rendering engine. It's open source, based on OpenGL/DirectX and C++.
      The full source code is hosted on github:
      https://github.com/fleissna/flyEngine

      I would appreciate if people with experience in game development / engine desgin could take a look at my source code. I'm looking for honest, constructive criticism on how to improve the engine.
      I'm currently writing my master's thesis in computer science and in the recent year I've gone through all the basics about graphics programming, learned DirectX and OpenGL, read some articles on Nvidia GPU Gems, read books and integrated some of this stuff step by step into the engine.

      I know about the basics, but I feel like there is some missing link that I didn't get yet to merge all those little pieces together.

      Features I have so far:
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      - Dynamic sorting of meshes to be renderd based on shader and material
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      - A very basic integration of the Bullet physics engine
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      - Caching mechanisms for textures, shaders, materials and meshes

      Features I would like to have:
      - Global illumination methods
      - Scalable physics
      - Occlusion culling
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      - Level Editing
      - Sound system
      - Optimization techniques

      Books I have so far:
      - Real-Time Rendering Third Edition
      - 3D Game Programming with DirectX 11
      - Vulkan Cookbook (not started yet)

      I hope you guys can take a look at my source code and if you're really motivated, feel free to contribute :-)
      There are some videos on youtube that demonstrate some of the features:
      Procedural grass on the GPU
      Procedural Terrain Engine
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      The long term goal is to turn this into a commercial game engine. I'm aware that this is a very ambitious goal, but I'm sure it's possible if you work hard for it.

      Bye,

      Phil
    • By tj8146
      I have attached my project in a .zip file if you wish to run it for yourself.
      I am making a simple 2d top-down game and I am trying to run my code to see if my window creation is working and to see if my timer is also working with it. Every time I run it though I get errors. And when I fix those errors, more come, then the same errors keep appearing. I end up just going round in circles.  Is there anyone who could help with this? 
       
      Errors when I build my code:
      1>Renderer.cpp 1>c:\users\documents\opengl\game\game\renderer.h(15): error C2039: 'string': is not a member of 'std' 1>c:\program files (x86)\windows kits\10\include\10.0.16299.0\ucrt\stddef.h(18): note: see declaration of 'std' 1>c:\users\documents\opengl\game\game\renderer.h(15): error C2061: syntax error: identifier 'string' 1>c:\users\documents\opengl\game\game\renderer.cpp(28): error C2511: 'bool Game::Rendering::initialize(int,int,bool,std::string)': overloaded member function not found in 'Game::Rendering' 1>c:\users\documents\opengl\game\game\renderer.h(9): note: see declaration of 'Game::Rendering' 1>c:\users\documents\opengl\game\game\renderer.cpp(35): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>c:\users\documents\opengl\game\game\renderer.cpp(36): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>c:\users\documents\opengl\game\game\renderer.cpp(43): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>Done building project "Game.vcxproj" -- FAILED. ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========  
       
      Renderer.cpp
      #include <GL/glew.h> #include <GLFW/glfw3.h> #include "Renderer.h" #include "Timer.h" #include <iostream> namespace Game { GLFWwindow* window; /* Initialize the library */ Rendering::Rendering() { mClock = new Clock; } Rendering::~Rendering() { shutdown(); } bool Rendering::initialize(uint width, uint height, bool fullscreen, std::string window_title) { if (!glfwInit()) { return -1; } /* Create a windowed mode window and its OpenGL context */ window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL); if (!window) { glfwTerminate(); return -1; } /* Make the window's context current */ glfwMakeContextCurrent(window); glViewport(0, 0, (GLsizei)width, (GLsizei)height); glOrtho(0, (GLsizei)width, (GLsizei)height, 0, 1, -1); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glfwSwapInterval(1); glEnable(GL_SMOOTH); glEnable(GL_DEPTH_TEST); glEnable(GL_BLEND); glDepthFunc(GL_LEQUAL); glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); glEnable(GL_TEXTURE_2D); glLoadIdentity(); return true; } bool Rendering::render() { /* Loop until the user closes the window */ if (!glfwWindowShouldClose(window)) return false; /* Render here */ mClock->reset(); glfwPollEvents(); if (mClock->step()) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glfwSwapBuffers(window); mClock->update(); } return true; } void Rendering::shutdown() { glfwDestroyWindow(window); glfwTerminate(); } GLFWwindow* Rendering::getCurrentWindow() { return window; } } Renderer.h
      #pragma once namespace Game { class Clock; class Rendering { public: Rendering(); ~Rendering(); bool initialize(uint width, uint height, bool fullscreen, std::string window_title = "Rendering window"); void shutdown(); bool render(); GLFWwindow* getCurrentWindow(); private: GLFWwindow * window; Clock* mClock; }; } Timer.cpp
      #include <GL/glew.h> #include <GLFW/glfw3.h> #include <time.h> #include "Timer.h" namespace Game { Clock::Clock() : mTicksPerSecond(50), mSkipTics(1000 / mTicksPerSecond), mMaxFrameSkip(10), mLoops(0) { mLastTick = tick(); } Clock::~Clock() { } bool Clock::step() { if (tick() > mLastTick && mLoops < mMaxFrameSkip) return true; return false; } void Clock::reset() { mLoops = 0; } void Clock::update() { mLastTick += mSkipTics; mLoops++; } clock_t Clock::tick() { return clock(); } } TImer.h
      #pragma once #include "Common.h" namespace Game { class Clock { public: Clock(); ~Clock(); void update(); bool step(); void reset(); clock_t tick(); private: uint mTicksPerSecond; ufloat mSkipTics; uint mMaxFrameSkip; uint mLoops; uint mLastTick; }; } Common.h
      #pragma once #include <cstdio> #include <cstdlib> #include <ctime> #include <cstring> #include <cmath> #include <iostream> namespace Game { typedef unsigned char uchar; typedef unsigned short ushort; typedef unsigned int uint; typedef unsigned long ulong; typedef float ufloat; }  
      Game.zip
    • By lxjk
      Hi guys,
      There are many ways to do light culling in tile-based shading. I've been playing with this idea for a while, and just want to throw it out there.
      Because tile frustums are general small compared to light radius, I tried using cone test to reduce false positives introduced by commonly used sphere-frustum test.
      On top of that, I use distance to camera rather than depth for near/far test (aka. sliced by spheres).
      This method can be naturally extended to clustered light culling as well.
      The following image shows the general ideas

       
      Performance-wise I get around 15% improvement over sphere-frustum test. You can also see how a single light performs as the following: from left to right (1) standard rendering of a point light; then tiles passed the test of (2) sphere-frustum test; (3) cone test; (4) spherical-sliced cone test
       

       
      I put the details in my blog post (https://lxjk.github.io/2018/03/25/Improve-Tile-based-Light-Culling-with-Spherical-sliced-Cone.html), GLSL source code included!
       
      Eric
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OpenGL Texture on Quad gets distorted

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Hello guys, I'm not really a OpenGL-programmer and are just using OpenGL for a little thing I have to do, so please don't laugh at me :) I have several GL_QUADS on which I apply a picture as a texture. However, when I rotate the surfaces, I noticed that the texture gets sort of "distorted". I've spent literally several hours searching Google to find a solution. Just after a few minutes I found out that this is caused because internally OpenGL "splits" my quad into two triangles. And this is exactly what happens: Even though it's supposed to look (sorta) like this: I've even spent several more hours to try out solutions but none of them really worked (for example using glTexCoord4f() instead of glTexCoord2f()), or of course I was doing something wrong. Here's my current code for the quad:
glBegin(GL_QUADS);
  glTexCoord2f(0.0f, 0.0f);
  glVertex3f(-item->width/2.0f, 0.0f, z); //bottom left

  glTexCoord2f(1.0f, 0.0f);
  glVertex3f(item->width/2.0f, 0.0f, z); //bottom right

  glTexCoord2f(1.0f, 1.0f);
  glVertex3f(item->width/2.0f, item->height, z); //top right

  glTexCoord2f(0.0f, 1.0f);
  glVertex3f(-item->width/2.0f, item->height, z); //top left
glEnd();
The only solution that is slightly improving the view is to use a GL_POLYGON and draw a polygon with lots of vertexes, but I don't think that's the only solution? Thank you guys in advance!

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Thanks. But I already tried that and as I said it didn't produce my expected result (probably because I'm totally lost on how to actually use it correctly).
I looked at the sample code and tried to use it on mine:

glBegin(GL_QUADS);
GLfloat tx = item->height * item->width/2.0f;

glTexCoord2f(0.0f, 0.0f);
glVertex2f(-item->width/2.0f, 0.0f); //Bottom Left

glTexCoord2f(1.0f, 0.0f);
glVertex2f(item->width/2.0f, 0.0f); //Bottom Right

glTexCoord4f(tx, tx, 0.0f, tx);
glVertex2f(item->width/2.0f, item->height); //Top Right

glTexCoord4f(-tx, tx, 0.0f, tx);
glVertex2f(-item->width/2.0f, item->height); //Top Left

glEnd();


That's what the original picture looks like:


And here's what I get :)


I obviously have no clue on how to use that tx-variable correctly... Can someone please clue me in or something?

Thanks.

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First of all, in openGL usually texure has inverted y's compared to Vertices.
glBegin(GL_QUADS);
//TexCoords
//0,1----1,1
//| |
//| |
//| |
//| |
//| |
//| |
//0,0----1,0
//VertexCoords
//-x,-y---- x,-y
// | |
// | |
// | |
// | |
// | |
// | |
//-x, y---- x, y
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-item->width/2.0f, item->height/2.0f, z); //bottom left
glTexCoord2f(1.0f, 0.0f);
glVertex3f(item->width/2.0f, item->height/2.0f, z); //bottom right
glTexCoord2f(1.0f, 1.0f);
glVertex3f(item->width/2.0f, -item->height/2.0f, z); //top right
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-item->width/2.0f, -item->height/2.0f, z); //top left
glEnd();

And second, most propably you may want to draw "from texture's middle" so it's good to have [-x/2,-y/2] to [x/2,y/2]
i fixed this for you, you're welcome.

PS. also this may become usefull as texcoord explaination
PS2. If this fails: divide the quad to two triangles AND figure out which Coords are needed.
glBegin(GL_TRIANGLES);//note that we can draw more than one figure between Begin and End
glTexCoord2f(0.0f, 0.0f);
glVertex3f(-item->width/2.0f, item->height/2.0f, z); //bottom left
glTexCoord2f(1.0f, 0.0f);
glVertex3f(item->width/2.0f, item->height/2.0f, z); //bottom right
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-item->width/2.0f, -item->height/2.0f, z); //top left
//TexCoords
//0,1----1,1
//| \ |
//| \ |
//| \ |
//| \ |
//| \ |
//| \ |
//0,0----1,0
//VertexCoords
//-x,-y---- x,-y
// | \ |
// | \ |
// | \ |
// | \ |
// | \ |
// | \ |
//-x, y---- x, y
glTexCoord2f(1.0f, 0.0f);
glVertex3f(item->width/2.0f, item->height/2.0f, z); //bottom right
glTexCoord2f(0.0f, 1.0f);
glVertex3f(-item->width/2.0f, -item->height/2.0f, z); //top left
glTexCoord2f(1.0f, 1.0f);
glVertex3f(item->width/2.0f, -item->height/2.0f, z); //top right
glEnd();



[Edited by - YanPL on April 4, 2008 12:32:08 PM]

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Hello,

Thanks for the quick replies and the sample codes.
Unfortunately splitting the image into two triangles results in the same perspective distortion as here:


Also, having the texture start in the middle (width/2, height/2) didn't help it either :(

@dpadam450
I'm not quite sure what you're talking about :P
But here's my GL init:
glEnable(GL_TEXTURE_2D);
glEnable(GL_DEPTH_TEST);
glEnable(GL_BLEND);

glDepthFunc(GL_LEQUAL);
glClearDepth(1.0f);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glShadeModel(GL_SMOOTH);

glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);


And my resize:
glViewport(0, 0, width, height);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();

GLfloat aspect = (GLfloat)width/(GLfloat)height;
GLfloat nearz = 0.1f;
GLfloat top = tan((90.0f*PI/180.0f)*0.5f)*nearz;

glFrustum(aspect*(-top), aspect*top, -top, top, nearz, 500.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();

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