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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 Trying to do skeletal visualization in bind pose similar to blender with octahedral mode

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I already achieved drawing octahedral by just porting blender code to c#+opentk. Here ported code:

static float[][] bone_octahedral_verts =new float[6][] {
	new []{ 0.0f, 0.0f,  0.0f},
	new []{ 0.1f, 0.1f,  0.1f},
	new []{ 0.1f, 0.1f, -0.1f},
	new []{-0.1f, 0.1f, -0.1f},
	new []{-0.1f, 0.1f,  0.1f},
	new []{ 0.0f, 1.0f,  0.0f}

		static int[][] bone_octahedral_solid_tris =new int[8][] {
	new []{2, 1, 0}, /* bottom */
	new []{3, 2, 0},
	new []{4, 3, 0},
	new []{1, 4, 0},

	new []{5, 1, 2}, /* top */
	new []{5, 2, 3},
	new []{5, 3, 4},
	new []{5, 4, 1}
		static float M_SQRT1_2=0.707106781186547524401f;
		/* aligned with bone_octahedral_solid_tris */
		static float[][] bone_octahedral_solid_normals =new float[8][] {
	new []{ M_SQRT1_2,   -M_SQRT1_2,    0.00000000f},
	new []{-0.00000000f, -M_SQRT1_2,   -M_SQRT1_2},
	new []{-M_SQRT1_2,   -M_SQRT1_2,    0.00000000f},
	new []{ 0.00000000f, -M_SQRT1_2,    M_SQRT1_2},
	new []{ 0.99388373f,  0.11043154f, -0.00000000f},
	new []{ 0.00000000f,  0.11043154f, -0.99388373f},
	new []{-0.99388373f,  0.11043154f,  0.00000000f},
	new []{ 0.00000000f,  0.11043154f,  0.99388373f}

		static void draw_bone_solid_octahedral(ref Matrix4 mat,float length)


	GL.MultTransposeMatrix(ref mat);
				for (var i = 0; i < 8; i++) {

				GL.PopMatrix ();

Originally blender used displayList+fixed pipeline but i removed displayList. As you see octahedron is normalized along Y axis (head is in {0,0,0} and tail is in {0,1,0}). This mean you have to multiply vertex with skeletal MVP matrix (matrix is loaded once before draw) and then is multiplied by inverted offset matrix for each bone - last thing is scale octa by length.


This gain me correct position and rotation. But i have serious trouble with length. I already spent 3 days for just trying fix length of octa for myself. I read multiple articles and posts including those in gamedev.net forum. Prolly most useful was this discussion: http://gamedev.stackexchange.com/questions/31959/getting-bone-base-and-tip-positions-from-a-transform-matrix

@Matt Kemp pointed out that i could find head and tail by multiplying {0,0,0} and {0,1,0}  (i chose Y axis since octa is normalized along Y axis) positions by one matrix from bone (local/global/offset?) then find length by subtracting these positions. I tried multiple variants of matrix calculations but always got no effect or too big effect (too small bone or too big).


I belive problem lie in matrix calculation or in their order. Here is my rest code for skeletal visualisation:


Loading skeleton (i use assimp.net):

using System;
using Assimp;
using Assimp.Configs;
using OpenTK;
using System.Linq;
using System.Collections.Generic;

namespace SharpAsset.Pipeline
	public class SkeletonPipeline: Pipeline
		public static readonly SkeletonPipeline singleton=new SkeletonPipeline();
		public Scene scene;
		private Dictionary<string,Assimp.Bone> boneNames;
		private List<Assimp.Node> rootBones;

		public override IAsset Import (string pathToFile)
			boneNames = new Dictionary<string, Assimp.Bone>();
			//rootBones = new List<Node> ();
			Assimp.Node rootBone=null;
			foreach (var mesh in scene.Meshes)
				foreach (var bone in mesh.Bones)
					boneNames.Add (bone.Name,bone);
			foreach(var boneName in boneNames.Keys){
				var boneNode=scene.RootNode.FindNode (boneName);
				if (boneNode.Parent == null || !boneNames.ContainsKey (boneNode.Parent.Name)) {
					rootBone = boneNode.Parent;
			var skele = new Skeleton ();
			skele.Name = "_Skeleton";
			skele[rootBone.Name]=CreateBoneTree (ref skele, rootBone,null);
			//bvh_to_vertices (skele[rootBone.Name],);
			Console.WriteLine ("/n Start bone list: /n"+rootBone.Name);
			return skele;
		void PrintBones(Bone n){
			Console.WriteLine (n.Name);
			foreach(var node in n.Children)
				PrintBones (node);
		private int _i;
		private Bone CreateBoneTree(ref Skeleton skele, Node node, Bone parent) {

			var internalNode = new Bone {
				Name = node.Name, Parent = parent,
			if (boneNames.ContainsKey (node.Name)) {
				boneNames [node.Name].OffsetMatrix.Transpose ();
				internalNode.Offset = FromMatrix (boneNames [node.Name].OffsetMatrix);

			}if (internalNode.Name == "") {
				internalNode.Name = "bone_" + _i++;
			//skele[internalNode.Name] = internalNode;
			var trans = node.Transform;
			trans.Transpose(); //drectx stuff
			internalNode.LocalTransform =FromMatrix(trans);
			internalNode.OriginalLocalTransform = internalNode.LocalTransform;
			internalNode.Children = new List<Bone> ();
			for (var i = 0; i < node.ChildCount; i++) {
				var child = CreateBoneTree(ref skele,node.Children[i], internalNode);
				if (child != null) {

			return internalNode;

		private static void CalculateBoneToWorldTransform(Bone child) {
			child.GlobalTransform = child.LocalTransform;
			var parent = child.Parent;
			while (parent != null) {
				child.GlobalTransform *= parent.LocalTransform;
				parent = parent.Parent;
		public override void Export (string pathToExport, string format)
			throw new NotImplementedException ();
		private Matrix4 FromMatrix(Matrix4x4 mat)
			Matrix4 m = new Matrix4();
			m.M11 = mat.A1;
			m.M12 = mat.A2;
			m.M13 = mat.A3;
			m.M14 = mat.A4;
			m.M21 = mat.B1;
			m.M22 = mat.B2;
			m.M23 = mat.B3;
			m.M24 = mat.B4;
			m.M31 = mat.C1;
			m.M32 = mat.C2;
			m.M33 = mat.C3;
			m.M34 = mat.C4;
			m.M41 = mat.D1;
			m.M42 = mat.D2;
			m.M43 = mat.D3;
			m.M44 = mat.D4;
			return m;

show skeleton code (highest level method in opengl renderer)

GL.LoadMatrix(ref skele.MVP);
//foreach (var childBone in skele.bones[0].Children)
var noscale=skele.bones[0].GlobalTransform.Inverted();
DisplayOcta (skele.bones[0],ref noscale);

DisplayOcta method:

void DisplayOcta(Bone bone, ref Matrix4 mvp){
            var mat =bone.Offset.Inverted();
            var copyMat =bone.Offset.Inverted()*bone.GlobalTransform;
            //copyMat.Transpose ();
            var final =copyMat;
            var head = Vector3.Transform (Vector3.Zero,final);
            var tail = Vector3.Transform (Vector3.UnitY,final);
            Console.WriteLine ((tail-head).Length);
            draw_bone_solid_octahedral (ref mat,(tail-head).Length);
            foreach (var childBone in bone.Children) 
                DisplayOcta (childBone,ref mvp);

draw_bone_solid_octahedral is already mentioned on the begining of post. These weird matrix multiplications are result of trying very hard to fix problem one way or another


here are pics to show the problem, first, see how it look in blender:




here is my scene view with exactly same sekeleton




as you see position and rotation of bone itself are same as in blender but length of bones are different

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