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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 Slightly confusing Z value problem

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I'm working on writing a simple graphics engine, and I've got the window creation and setup for OGL working fine, but drawing seems to be another matter.
while( engine.run() ){
	driver->beginScene();	// clears the window with glClear




		glColor3f(1.0f, 1.0f, 1.0f);
		glVertex3f(0,   0,   1);
		glVertex3f(50,  100, 1);
		glVertex3f(100, 50,  1);



	driver->endScene();	// actually renders the window

Here's what I'm trying to draw just to make sure that drawing works. I have this drawing, but something is confusing me. Why am I able to see it? I was under the impression that when you draw something at a positive z value, then it is drawn behind the camera, and a negative z value is in front of the camera. I mean, I haven't moved the camera or anything. Here's my OGL init code, and the beginScene and endScene functions:
 * Initialises the video driver.
 * \param screenSize A dimension2d object containing the height and width of the screen
bool COpenGLDriver::initDriver(const video::dimension2d& screenSize)
	int nPixelFormat;

		sizeof(PIXELFORMATDESCRIPTOR),		// size of the structure
		1,									// version. Always set to 1
		PFD_DRAW_TO_WINDOW |				// support window
		PFD_SUPPORT_OPENGL |				// support opengl
		PFD_DOUBLEBUFFER,					// support double buffering
		PFD_TYPE_RGBA,						// RGBA color mode
		32,									// 32-bit color mode
		0, 0, 0, 0, 0, 0,					// ignore color bits, not used
		0,									// no alpha buffer
		0,									// ignore shift bit
		0,									// no accumulation buffer
		0, 0, 0, 0,							// ignore accumulation bits
		16,									// 16-bit z-buffer size
		0,									// no stencil buffer
		0,									// no auxillary buffer
		PFD_MAIN_PLANE,						// main drawing plane
		0,									// reserved
		0, 0, 0								// layer masks ignored

	// if get hdc fails
	if( !(hDC = GetDC(Window)) ){
		util::Message::print("COpenGLDriver::initDriver: Cannot create a GL device context.");
		return false;

	// chose best matching pixel format, return index
	if( !(nPixelFormat=ChoosePixelFormat(hDC, &pfd)) ){
		util::Message::print("COpenGLDriver::initDriver: Cannot find a suitable pixel format.");
		return false;

	// set pixel format to device context
	if( !SetPixelFormat(hDC, nPixelFormat, &pfd) ){
		util::Message::print("COpenGLDriver::initDriver: Cannot set the pixel format.");
		return false;

	// create rendering context
	if( !(hRC=wglCreateContext(hDC)) ){
		util::Message::print("COpenGLDriver::initDriver: Cannot create a GL rendering context.");
		return false;

	// activate rendering context
	if( !wglMakeCurrent(hDC, hRC) ){
		util::Message::print("COpenGLDriver::initDriver: Cannot activate GL rendering context.");
		return false;

	glViewport(0, 0, (int)screenSize.width, (int)screenSize.height);	// reset the current opengl viewport

	glShadeModel(GL_SMOOTH);		// enable smooth shading

	glDisable(GL_LIGHTING);			// lighting disabled
	glFrontFace(GL_CW);				//

	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);		// really nice perspective calculations

	glClearDepth(1.0f);			// set gl clear depth

	return true;	// init went well

 * Does OGL housekeeping, like clearing the screen and depth buffer
 * \param c A CColor object that represents the color to clear the screen to. Defaults to black.
void COpenGLDriver::beginScene(video::CColor c = video::CColor(0.0f,0.0f,0.0f))
	glClearColor(	c.getRedFloat(), c.getGreenFloat(),
					c.getBlueFloat(), c.getAlphaFloat()
				);						// Set clear color

	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);// Clear Screen And Depth Buffer

 * Does OGL housekeeping for the end of rendering a frame.
void COpenGLDriver::endScene()
	SwapBuffers(hDC);	// render the scene to the window

Is it something that I've done in complete ignorance? I am able to see the triangle in a range of about -1 to +1. Any ideas? Because this doens't look different from other OGL init code that I've gotten from tutorials.

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Yes, you are correct about the way z values work.
To nitpick, opengl doesn't actually think of the view in terms of a "camera". Think of it in terms of moving the object you're drawing towards (positive) or away from (negative) the viewer. You can always perform a translation first if you prefer to use positive numbers. Do it before your calls to glBegin ... glEnd and not during.

glTranslatef(0.0f,0.0f,-10.0f) or something. What that's doing in english is moving the object 10 units into the screen along the z axis (away from the camera).

You can only see the triangle in a short range onscreen because the viewing frustum (what you can see onscreen) is set up this way by default. You can alter this:

glViewport (0, 0, (GLsizei)(windowwidth), (GLsizei)(windowheight)); // Reset The Current Viewport
glMatrixMode (GL_PROJECTION); // Select The Projection Matrix
glLoadIdentity (); // Reset The Projection Matrix
gluPerspective (45.0f, (GLfloat)(windowwidth)/(GLfloat)(windowheight),1.0f, 500.0f); // Calculate The Aspect Ratio Of The Window
glMatrixMode (GL_MODELVIEW); // Select The Modelview Matrix
glLoadIdentity (); // Reset The Modelview Matrix

Could be placed in the initialisation routine, although it would serve much better as part of a routine called when the window is resized as well. The key part is the gluPerspective call. (you'll need to #include <gl/glu.h>) 45.0f is the fov in the y direction (in degrees), and the 1.0f and 500.0f correspond to the front and back clipping planes of the view frustum, and are always positive values. In this example, you will only see things that are at least 1.0f in front of the "camera", and at most 500.0f units away from (still in front of) the camera. Try playing with these values.

When you rotate the camera around on the screen, you're actually rotating the objects around the camera (initially, but if you do translations followed by rotations this isn't true), but in any case it means that polygons with negative z values will be visible when you rotate them into view.

Hope that helps

Also, you're using the glVertex3f command, which expects coordinates specified using floats. Although it doesn't really matter that much, get into the habit of writing 1.0f instead of 1 (as that's an integer). Makes no difference to a human but it'll get rid of some compilation warnings (it's satisfying to see your code compile with 0 warnings & 0 errors :) )

i.e. glVertex3f(0.0f, 0.0f, 1.0f);

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