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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:

      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:
      - Dynamic shader generation based on material properties
      - Dynamic sorting of meshes to be renderd based on shader and material
      - Rendering large amounts of static meshes
      - Hierarchical culling (detail + view frustum)
      - Limited support for dynamic (i.e. moving) meshes
      - Normal, Parallax and Relief Mapping implementations
      - Wind animations based on vertex displacement
      - A very basic integration of the Bullet physics engine
      - Procedural Grass generation
      - Some post processing effects (Depth of Field, Light Volumes, Screen Space Reflections, God Rays)
      - Caching mechanisms for textures, shaders, materials and meshes

      Features I would like to have:
      - Global illumination methods
      - Scalable physics
      - Occlusion culling
      - A nice procedural terrain generator
      - Scripting
      - 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
      Quadtree detail and view frustum culling

      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.


    • 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 ==========  
      #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; }  
    • 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!
    • By Fadey Duh
      Good evening everyone!

      I was wondering if there is something equivalent of  GL_NV_blend_equation_advanced for AMD?
      Basically I'm trying to find more compatible version of it.

      Thank you!
    • By Jens Eckervogt
      Hello guys, 
      Please tell me! 
      How do I know? Why does wavefront not show for me?
      I already checked I have non errors yet.
      using OpenTK; using System.Collections.Generic; using System.IO; using System.Text; namespace Tutorial_08.net.sourceskyboxer { public class WaveFrontLoader { private static List<Vector3> inPositions; private static List<Vector2> inTexcoords; private static List<Vector3> inNormals; private static List<float> positions; private static List<float> texcoords; private static List<int> indices; public static RawModel LoadObjModel(string filename, Loader loader) { inPositions = new List<Vector3>(); inTexcoords = new List<Vector2>(); inNormals = new List<Vector3>(); positions = new List<float>(); texcoords = new List<float>(); indices = new List<int>(); int nextIdx = 0; using (var reader = new StreamReader(File.Open("Contents/" + filename + ".obj", FileMode.Open), Encoding.UTF8)) { string line = reader.ReadLine(); int i = reader.Read(); while (true) { string[] currentLine = line.Split(); if (currentLine[0] == "v") { Vector3 pos = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inPositions.Add(pos); if (currentLine[1] == "t") { Vector2 tex = new Vector2(float.Parse(currentLine[1]), float.Parse(currentLine[2])); inTexcoords.Add(tex); } if (currentLine[1] == "n") { Vector3 nom = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inNormals.Add(nom); } } if (currentLine[0] == "f") { Vector3 pos = inPositions[0]; positions.Add(pos.X); positions.Add(pos.Y); positions.Add(pos.Z); Vector2 tc = inTexcoords[0]; texcoords.Add(tc.X); texcoords.Add(tc.Y); indices.Add(nextIdx); ++nextIdx; } reader.Close(); return loader.loadToVAO(positions.ToArray(), texcoords.ToArray(), indices.ToArray()); } } } } } And It have tried other method but it can't show for me.  I am mad now. Because any OpenTK developers won't help me.
      Please help me how do I fix.

      And my download (mega.nz) should it is original but I tried no success...
      - Add blend source and png file here I have tried tried,.....  
      PS: Why is our community not active? I wait very longer. Stop to lie me!
      Thanks !
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OpenGL Glsl ray tracing

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I'm trying to make a ray tracer in OpenGL compute shaders. I have just made it so the rays can collide with spheres with no secondary rays or lighting effects but it runs really slow with even just a few spheres at around 50ms per frame. I changed it so the compute shader didn't try anything which made it quite a bit faster. Can anyone see what could be slowing it down?. Each ray loops through every shape and tries to intersect it


here is the compute shader



#version 430 core
layout (local_size_x = 1, local_size_y = 1) in;
layout(rgba32f, binding = 0) uniform image2D img_output;

uniform vec3 playerView;
uniform mat4 viewMatrix;
vec3 spherePositions[3] = {vec3(0.0f,0.0f, 3.0f),vec3(-1.0f,0.0f, 2.0f),vec3(3.0f,-50.0f,100.0f)};
float sphereRadii[3] = {1.0f, 0.3f,50.0f};
vec4 computeSphereIntercept(vec3 ray,float closestRayHit,vec3 position,float radius,vec3 colour);

void main() {
    //vec4 pixel = vec4(1.0f,1.0f,1.0f, 1.0);
    ivec2 pixelCoords = ivec2(gl_GlobalInvocationID.xy);
    vec4 collision = vec4(1.0f,1.0f,1.0f,100.0f);

    vec3 ray = normalize(vec3(mix(-1.33,1.33,(pixelCoords.x/800.0)),mix(1,-1,(pixelCoords.y/600.0)),1));
    //float nearestRayHit = 100.0f;
    for(int i = 0;i < 3;i++){
        if(length(cross(ray,spherePositions))-length(spherePositions) <= sphereRadii){
            collision = computeSphereIntercept(ray,collision.w,spherePositions,sphereRadii,collision.xyz);


        //nearestRayHit = collision.w;
        //pixel = vec4(collision.xyz,1.0f);

    // output to a specific pixel in the image
    imageStore(img_output, pixelCoords, vec4(collision.xyz,1.0f));

vec4 computeSphereIntercept(vec3 ray,float closestRayHit,vec3 position,float radius,vec3 colour){
    vec3 spherePos = (viewMatrix * vec4(position,1.0f)).xyz;

    float distRaySphereCollision = dot(ray,spherePos);
    vec3 raySphereCollision = ray*distRaySphereCollision;
    //float centerToRaySphereCollision = length(raySphereCollision-spherePos);
    float centerToRaySphereCollision = pow(raySphereCollision.x-spherePos.x,2)+pow(raySphereCollision.y-spherePos.y,2)+pow(raySphereCollision.z-spherePos.z,2);
    float interceptEdgeFromRaySphereCollision = sqrt(pow(radius,2)-centerToRaySphereCollision);
    if(closestRayHit > distRaySphereCollision-interceptEdgeFromRaySphereCollision && distRaySphereCollision > 0 && centerToRaySphereCollision <= radius*radius && pow(spherePos.x,2)+pow(spherePos.y,2)+pow(spherePos.z,2) >= radius*radius){
        closestRayHit = distRaySphereCollision-interceptEdgeFromRaySphereCollision;
        colour = vec3(1.0f,0.0f,0.0f);
    else if(closestRayHit > distRaySphereCollision+interceptEdgeFromRaySphereCollision && pow(spherePos.x,2)+pow(spherePos.y,2)+pow(spherePos.z,2) < radius*radius){
        closestRayHit = distRaySphereCollision-interceptEdgeFromRaySphereCollision;
        colour = vec3(1.0f,0.0f,0.0f);

    return vec4(colour.xyz,closestRayHit);



how it determines collision with a sphere is it finds the distance to the point where it makes a 90 degrees angle from that point to the sphere and that point to the camera, if the distance from  that point to the sphere is bigger than its radius no collision, if the distance is less than it finds the exact spot where it hits with one square root I think.



Edited by Ben Danger

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Each ray loops through every shape

This could be the cause.

Normally one's trying to implement some kind of partitioning. kD-trees layed up linearly in memory, bounding hierarchies, etc.

I didn't trace rays myself though, but quite good results was achieved in the era before computing shaders.

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Each ray loops through every shape

This could be the cause.
Normally one's trying to implement some kind of partitioning. kD-trees layed up linearly in memory, bounding hierarchies, etc.
I didn't trace rays myself though, but quite good results was achieved in the era before computing shaders.

I was planning on using octrees for storing voxels. Are you familiar with voxel quest? I'm pretty sure it uses ray tracing, how could it be possible to have such high res graphics like it? Although I'm not expecting to have anything that good it just bugs me that it's possible and I can't figure out how

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layout (local_size_x = 1, local_size_y = 1) in;


This means only one thread out of 32 on NV or 64 on AMD does any work, all other threads are idle.


Change to local size of 8 each, so one thread group opereates on 8x8 pixels.

Each thread needs to pick the proper pixel to construct it's ray, the rest of the code probably don't needs much changes.

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I canged the local size to 8 x 8 and if anything hte performance is worse, is this correct for local size of 8 x 8?
glDispatchCompute((GLuint)SCREENWIDTH, (GLuint)SCREENHEIGHT, 1);

I tested it it with a global size of SCREENWIDTH/8 and SCREENHEIGHT/8 and it runs much faster. It seems that originally I was having 63 inactive shader threads then when I changed the local size to 8x8 i was accidentally drawing 64x the pixels than the screen had.

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