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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:
      - 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.

      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
    • 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 Opengl Multiple renderings, how to improve performance?

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Hello everybody I am working on an application that needs to render the scene from multiple points of view. I notice that if I render once, even if the frag shader is long and complicated (writing to multiple 3D textures) it runs at 65 FPS. As soon as I add another rendering pass before that (simply rendering to 2 targets, colour and normals+depth) the framerate drops to 40. If I add a shadowmap pass it drops even further to 25-30 FPS. What is the best way to cope with multiple renderings and still retain a high framerate?

 

This is what I have right now:

1 - a shader that computes the normal+depth and colors, 2 targets on the same FBO

2 - the same shader gets called again for the shadowmap (different uniform parameters) but renders to a different FBO target

3 - a shader that writes values on a 3D texture using imageStore, new FBO

4 - a last shader that performs ray marching through the 3D texture and, at the same time, reads from the 2 maps created before

if i just run step 3 and 4 i get 65 FPS, if i add the 2 steps above the performance drops and the only explanation I have is that I am doing something useless in the middle cause the shaders in 3 and 4 are way more complicated (1000+ lines)

Thank you 

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It's not strange that a severely un-optimized shader of 20 lines will get outperformed by a severely optimized shader of 100 lines (so to speak that is). Add the fact that you're using the same shader multiple times to render multiple viewpoints and your performance will go down the drain.

 

With that being said, we have no clue what your shaders look like so we can't really comment on anything if you're doing something wrong or not. It might be in the shaders, it might be in the way you are using the FBO, it might be something totally unrelated to either!

 

I'd suggest using a profiler to see where your bottleneck is, (double) check your shaders (1000+ lines for a single shader seems like a lot, but I don't know what you're aiming for) and check your code for silly mistakes.

 

But if you want help, post some code along with an explanation of what you're trying to achieve and I'm sure these lovely people are able to help you out!

Edited by Rld_

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I have Nsights installed in VS 13, would it work as a profiler for glsl? Btw the big shader is fine cause everything runs fast when i run it alone. The other one is slowing things down, Also, I have 5 FBOs with a total of 6 targets, maybe this is one of the things that is slowing down everything

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I never used Nsights before, but it seems like an option to rule some things out, but I'm not sure if it enables you to profile your shaders. A quick google already showed some options for you that might do the trick a bit better specifically for shaders.

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So I started doing some debugging with Nsight and I took a look at the events. This is what I saw:

 

I have numerous calls like this 

void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 15)	0x00010000	1539	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 1188, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 000354FC, GLint basevertex = 38051)	0x00010000	21038	22504
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003678C, GLint basevertex = 38847)	0x00010000	17446	15872
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 000373D4, GLint basevertex = 39373)	0x00010000	16933	15292
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003801C, GLint basevertex = 39899)	0x00010000	21552	14868
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 00038C64, GLint basevertex = 40425)	0x00010000	17960	14080
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 1188, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 000398AC, GLint basevertex = 40951)	0x00010000	16933	21740
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 1188, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003AB3C, GLint basevertex = 41747)	0x00010000	16420	21856
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003BDCC, GLint basevertex = 42543)	0x00010000	16933	15432
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003CA14, GLint basevertex = 43069)	0x00010000	16933	15448
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003D65C, GLint basevertex = 43595)	0x00010000	16420	14704
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 786, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003E2A4, GLint basevertex = 44121)	0x00010000	16933	13788
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 1188, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0003EEEC, GLint basevertex = 44647)	0x00010000	16420	21668

and I guess I could turn those draw calls into a single call.

I then noticed this other thing:

void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 10)	0x00010000	1539	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 612, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0004017C, GLint basevertex = 45443)	0x00010000	21038	30748
void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 12)	0x00010000	1026	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 612, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 00040B0C, GLint basevertex = 45959)	0x00010000	20525	28388
void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 10)	0x00010000	1026	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 444, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0004149C, GLint basevertex = 46475)	0x00010000	20525	55416
void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 11)	0x00010000	1026	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 480, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 00041B8C, GLint basevertex = 46797)	0x00010000	20525	13716
void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 12)	0x00010000	1026	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 336, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0004230C, GLint basevertex = 47117)	0x00010000	20525	10060
void glBindTexture(GLenum target = GL_TEXTURE_2D, GLuint texture = 11)	0x00010000	1026	0
void glDrawElementsBaseVertex(GLenum mode = GL_TRIANGLES, GLsizei count = 480, GLenum type = GL_UNSIGNED_INT, GLvoid* indices = 0004284C, GLint basevertex = 47349)	0x00010000	20525	11676

Now in this one as you can notice I keep binding to the same 3 textures back and forth. Would it make sense to sort my elements based on texture object when I load the model, so that I can bind one texture and make all the draw calls and then go to the next?

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I'm not sure how expensive texture binding is, but it will probably increase performance by some if you keep it all together. Constantly (re)binding shaders is a costly thing, so you probably do want to have that sorted out.

 

Having less draw calls might also help.

 

You might also benefit from timing your instructions, see if something is taking up more time than it should. Most, if not all, profilers have an option to see your highest bottlenecks, but you can also time specific functions yourself if you want that.

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I notice that if I render once, even if the frag shader is long and complicated (writing to multiple 3D textures) it runs at 65 FPS1. As soon as I add another rendering pass before that (simply rendering to 2 targets, colour and normals+depth) the framerate drops to 40 FPS2. If I add a shadowmap pass it drops even further to 25-30 FPS3

That's 1=15.4ms, 2=25ms, 3=40 to 33ms per frame maximum from the CPU and GPU.

So your original pass is 15.4ms, your added pass is (25-15.4=) 9.6ms, and your shadowmap pass is (33-25= / 40-25=) 8ms to 15 ms.
 
Those all sound like feasible numbers... I don't know why you expect to be able to do more work without spending more milliseconds of GPU time wink.png tongue.png
 
You can use gl_ext_timer_query to measure how long different passes are taking on the GPU. e.g. insert a query before/after your shadowmap pass, and then next frame, retrieve the results of the query to find out what the duration of those commands on the GPU actually was.

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Actually I turned off vsync so that I get the actual FPS. So these are the actual results (voxelization is the expensive shader)

 

voxelization alone: 94 FPS

 

normal+depth and color pass alone: 240 FPS (I could improve this by using a g-buffer instead of 2 textures)

 

shadowmap alone: 135 FPS

 

normal+depth+color & shadowmap: 160 FPS (those 2 passes use the same shader)

 

second pass + shadowmap + voxelisation (in this order) : 67 FPS

 

The weird thing is that if I run the shadowmap pass alone it's slower than if i run it after th other pass, so it means that I am probabily wasting something. 

I will go on and try to optimize the voxelisation part. It's the cyril crassin method of rendering everything while using the geometry shader to project to the dominant axis and use the fragment shader to write to a 3d texture. Right now I am writing to the 3d Tex by using imageStore even though that doesn't seem the bottleneck of the shader.

 

If I use gl_ext_timer_query i get those results

 

normal+depth & color : 10,336,416 ns

shadowmap: 5,412,064 ns

voxelise: 55,344,416 ns

which should run at 14 fps...

 

all I did was

glBeginQuery(GL_TIME_ELAPSED_EXT, queries[0]);
firstPass();
glEndQuery(GL_TIME_ELAPSED_EXT);
glBeginQuery(GL_TIME_ELAPSED_EXT, queries[1]);
ShadowMapPass();
glEndQuery(GL_TIME_ELAPSED_EXT);
glDisable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glBeginQuery(GL_TIME_ELAPSED_EXT, queries[2]);
Voxelize(false);
glEndQuery(GL_TIME_ELAPSED_EXT);

while (!available) {
	glGetQueryObjectiv(queries[4 - 1], GL_QUERY_RESULT_AVAILABLE, &available);
}
for (int i = 0; i < 3; i++) {
  // See how much time the rendering of object i took in nanoseconds.
  glGetQueryObjectui64vEXT(queries[i], GL_QUERY_RESULT, &timeElapsed);
}

I assure that the fps count above is correct because it is the same one that is displayed by NSight

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As demonstrated by Hodgman above: Using a non-linear measure like FPS (which is in fact reciprocal) is meaningless for quantitative assessment of relative performance. 

 

However, in your query code, IMHO this line

glGetQueryObjectiv(queries[4 - 1], GL_QUERY_RESULT_AVAILABLE, &available);

should read so

glGetQueryObjectiv(queries[3 - 1], GL_QUERY_RESULT_AVAILABLE, &available);

because you want to wait for queries[2] to be ready, not for (the not existing) queries[3].

Edited by haegarr

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