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    • By racarate
      Hey everybody!
      I am trying to replicate all these cool on-screen debug visuals I see in all the SIGGRAPH and GDC talks, but I really don't know where to start.  The only resource I know of is almost 16 years old:
      http://number-none.com/product/Interactive Profiling, Part 1/index.html
      Does anybody have a more up-to-date reference?  Do people use minimal UI libraries like Dear ImgGui?  Also, If I am profiling OpenGL ES 3.0 (which doesn't have timer queries) is there really anything I can do to measure performance GPU-wise?  Or should I just chart CPU-side frame time?  I feel like this is something people re-invent for every game there has gotta be a tutorial out there... right?
    • 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:

      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!
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OpenGL 2D lighting in OpenGL with GLSL, how?

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Hello everyone!

I am new to this forum so sorry it I posted this in the wrong section.

Anyways, I want to create 2D lightning with GLSL just like here:


And here:


I am using Java for my game. I was just wondering, how would I achieve this?

I am currently able to draw a light using LWJGL's built in functions like glLight but I am not sure how to add lights like in the videos!


Please help I've been searching the net for 2 days but without any success...

Any help would be appreciated!

Thank you very much!

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Hey, thanks for you answer!

I already saw this but it doesn't really show me how to do it with code.

Hopefully I will find something :)

Been searching for 2 Days.... Even posted a question on Stack Overflow....

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looks liek its 2d  so then.


you draw everything in screen coords first of all you put everything between -1..1 in vertex buffer


same for positions of lights you define the radius of light that is properly scaled, you draw the light now you test every fragment with every occluder  (or you can make a 2d texture that already makes the shadow volume <- this seems reasonable unless you kniwo how to pass multiple objects to shader)


rest looks obvious... loop through lights apply the correct fragment.

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Thanks WiredCat!

I understand the concept fully now :)

Still kind of confused with the actual code...

From other sources on the net I realised that lightning is actually making an image darker. I would need to render my normal scene and a black rectangle on top of it. Then add transparency or coloring where the light is.


Once again, still confused with the code :)

I could REALLY use an example, it would be easier to learn.


Thank you very much for your answer!

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since when light darkens the image you start with completely black scene,, then you blend the result for each light with lets say



unfortunatetly i never wrote such thing, so i cant provide you with the code.


But first of all you could tell me if you even know how to render a quad that is 32x32 pixels at the center of the screen? well if not, then giving you a sample code would be really unwise

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second video on post above mine  actually says how shadows are rendered, you need really to consider how you want to cast shadows yourself, do that on cpu or gpu, anyway you  will have to pass (im talking about that second yt vid) a set of points to shader for every occluder that will tell your shader (in gpu shadowcomputing)  that everything between those two (actualy 2 volumes, 4 verts cast that) is black even blacker than MicroblackShotgun 55 smile.png




Btw that tutorial on nehe is outdated and uses FixedFunctionPipeline which is not what you want to use in 2015, i am not sure how this could help you since you say its an eaisiest thing to do thats the only thing you need to know, along with sending shadowcasters to the shader) (or making that on cpu whioch will be easier but slower)


so i think you really dont know how to draw that quad in the center



for gpu implementation and without taking into account unifroms and unfirmbuffers you could store in first pixel number of occluders. then for every next  pixels you could apply there occluders positions, then in main lighting shader you will form a triangle (or two planes when you loop throug occluders) and if anything is between the shadowvlume you make it black.


since he draws a quad that is somewhat a filled circle with radius of rect_size/2.0 you will need some kind of bias, 

Edited by WiredCat

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Well, since I can't find any good tutorials on how to do lightning in 2D I am stuck with whatever I can find smile.png


I'll see what I can do with shaders. Hoping to implement lightning soon smile.png


Oh, and are you talking about drawing a quad in the center using ONLY GLSL or using Java aswell? Because In Java it's way to easy... glBegin(GL_QUADS); glVertex2f(...).... Sorry I'm to lazy to write it down now tongue.png



Alright just saw you edited your last post. I'm looking at it super confused haha

Edited by mateo226

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well after defining the RADIUS and LIGHT COLOR IN THE SHADER you could do that


vertex shader:

attribute vec3 Vpos;
varying vec2 vert;

void main()
vert = Vpos.xy; //pass texture coord
gl_Position = vec4(Vpos.xy, 0.0, 1.0);

in fragment


something liek that:

varying vec2 vert;

varying vec3 vertex_pos;
uniform vec3 LPOS;
uniform vec3 LDIFF;

uniform float LRadius;

float n3ddistance(vec3 first_point, vec3 second_point)
float x = first_point.x-second_point.x;
float y = first_point.y-second_point.y;
float z = first_point.z-second_point.z;
float val = x*x + y*y + z*z;
return sqrt(val);

void main()
	float dst = n3ddistance(LPOS, vertex_pos);
	float intensity = clamp(1.0 - dst / LRadius, 0.0, 1.0);
	vec4 color = vec4(LDIFF.x, LDIFF.y, LDIFF.z, 1.0)*intensity;
	gl_FragColor = color;

ofc that wont compile i just mixed two different shaders


vertex is from drawing a fullscreen quad on screen 


second is a pointlight but in 3d so (additionallyi pass a vertex position to fragment shader)


looks like this:



still one thing to consider you need to know if you will pass light radius in ndc coord (or screen coords ) or in worldspace coords everything is enterely up to you

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