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    • 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. 
      Now I've hit a point where I want to remove one of these instances of object A while the game is running, but I'm not quite sure how to go about it. At first my thought was to update the instanced attribute of Object A and change the positions to some dummy number that I could catch in the vertex shader and then decide there whether to draw the instance of Object A or not, but I think that would be expensive to do while the game is running, considering that it might have to be done several times every frame in some cases. 
      I'm not sure how to proceed, anyone have any tips?
    • 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!
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OpenGL Getting OpenGL functioins

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Hey, guys.

 

I've got very annoying error when trying to build my app using VisualStudio.

 

Here is complete error stack

Error       linker command failed with exit code 1 (use -v to see invocation)   PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\clang.exe  1
Error       undefined reference to 'glGetAttribLocation'    PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   70
Error       undefined reference to 'glCreateProgram'    PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   87
Error       undefined reference to 'glAttachShader' PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   91
Error       undefined reference to 'glAttachShader' PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   92
Error       undefined reference to 'glLinkProgram'  PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   93
Error       undefined reference to 'glGetProgramiv' PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   96
Error       undefined reference to 'glDeleteProgram'    PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   100
Error       undefined reference to 'glCreateShader' PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   111
Error       undefined reference to 'glShaderSource' PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   115
Error       undefined reference to 'glCompileShader'    PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   116
Error       undefined reference to 'glGetShaderiv'  PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   119
Error       undefined reference to 'glGetShaderiv'  PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   124
Error       undefined reference to 'glDeleteShader' PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   128
Error       undefined reference to 'glUseProgram'   PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   172
Error       undefined reference to 'glVertexAttribPointer'  PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   174
Error       undefined reference to 'glEnableVertexAttribArray'  PewPew.NativeActivity   c:\workspace\PewPew\PewPew\PewPew.NativeActivity\Renderer.cpp   175

Well, it seems to be related to OpenGL calls, but I can't understand how exactly.

I've already included

#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>
#include <EGL/egl.h>
#include <GLES/gl.h>

but still no luck.

Any suggestions about what am I doing wrong?

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Probably easiest thing to do is use one of the libraries that takes care of managing openGL extensions for you.

I personally don't use them much because the rendering engines I make are not exactly conventional so I can't really recommend a specific solution. However I do know many people use and have success with GLEW, SDL, GLFW, and not sure what else but there are a few solutions if you google for it.

 

Failing that you can just import them yourself if you only need a few openGL functions and don't want to use a library for some reason, but I don't really recommend it.

For example:

const PFNGLCREATEPROGRAMPROC glCreateProgram = ((PFNGLCREATEPROGRAMPROC)wglGetProcAddress("glCreateProgram"));
Edited by JeffRS

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These are linker errors.  Building a C/C++ executable (and I'm simplifying a lot here) involves two primary steps: compiling your C/C++ source code to object code, then linking your object code together with object code from external libraries to make the final executable.

 

Header files are only relevant for the compiling step and they're sufficient to tell the compiler what function signatures, data types, etc to expect.

 

For linking you also need library files: .lib or .o or whatever, depending on your OS and toolchain.  Header files on their own are not enough, so hence the errors.

 

You mentioned Visual Studio so that brings us to the next piece of information: there are no native library files available for OpenGL versions beyond 1.1 in Windows.  The way to access higher functionality is to use the extension loading mechanism (this is not the same thing as using extensions; a misunderstanding I've seen before elsewhere) to get the entry points.

 

That gets messy which is why the general recommendation you'll see a lot is to use an extension loading library instead of doing it yourself manually.  GLEW is the one that is typically recommended and you're probably going to have the easiest time finding documentation and help on it: http://glew.sourceforge.net/

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Try adding GLESv2 to properties->linker->input->additional dependencies. If it is an option then why not try using v3.1? I didn't have any issues with getting functions (didn't need to) nor linking. Just:

 

#include <EGL/egl.h>
#include <GLES3/gl31.h>
 
and addding
GLESv3
EGL
to library dependancies.
 
Of course if you are limited by the platform you are targeting that won't be an option.

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mhagain

 

I'm sorry, I forgot to mention, that I'm developing an Android application (using NativeActivity), so I'm not sure about an opportunity to use GLEW...

 

Is there another way to use that extension loading mechanism?

Edited by Fennec

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you need to link es2 lib in android.mk file 

 

 

LOCAL_LDLIBS := -llog -landroid -lGLESv2

 

then you just add headers:

 

#include <GLES2/gl2.h>
#include <GLES2/gl2ext.h>

 

 

should work

 

 

//edit comment to that below: uh oh : )

Edited by WiredCat

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WiredCat,
 
Visual Studio doesn't contain make files in NativeActivity applications...
 
 
Nanoha
 
Sorry, I'm very new in all that stuff. Could you please tell me a little bit more detailed about how do I add additional dependencies? I mean, I've found this menu, but if I just put "GLESv2" string here, and try to build my project, it says 

 

Error no such file or directory: 'GLESv2'

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Nanoha
 
Sorry, I'm very new in all that stuff. Could you please tell me a little bit more detailed about how do I add additional dependencies? I mean, I've found this menu, but if I just put "GLESv2" string here, and try to build my project, it says 

 

Error no such file or directory: 'GLESv2'

 

 

I'll start by saying I've just made an Android app using Visual Studio's NativeActivity Application project. It starts out using GLES 1 which at first I tried to change but I had difficulty and just went 'old school' and made do but eventually I needed shaders so I put the effort in to getting my project compiling and linking with GLES 3.1 (I had to change a lot..).

 

I messed a round a lot to get it working but I believe all you need to do is:

open your precompile header pch.h) and add:

#include <EGL/egl.h>
#include <GLES3/gl31.h>
 
If there are other opengl headers being added there remove them.
 
Next right click on your project (PewPew.NativeActivity) and select properties. Expand the linker group and select input. Then in the right pane you should see an option "Library Dependancies". Make sure EGL is there and GLESv3. They should be separated by semicolons. Mine looks like:
%(LibraryDependencies);GLESv3;EGL;m
The 'm' is just the maths lib so you only need that if you are going to be using it.
 
Other than changing my old GLES1 code to the more modern way of doing things I don't recall having to change much to get it building and linking. I didn't need to get any function addresses or install anything to do that for me (such as GLEW).
Edited by Nanoha

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