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• ### Similar Content

• 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:
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

# OpenGL OpenGL 3.2+ and GLSL texturing

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Hello all, I have recently begun the switch from old OpenGL to the newer specification that uses VAO's and VBO's for like... everything.
I am having alot of trouble getting texturing to work with GLSL and my VAO's, I managed to get lighting and color with GLSL working earlier(using an individuale VBO for ther verts, color, and normals) so i know my view/projection/model matrixies are all okay. I manually generate all the verticies of a cube into v[108] (im not using TRIAGLE_STRIPS right now so its 2 tri's a side) and then the tex coords for each vertex into t[72]. Since each vertex of 3 floats only requires two tex coords right? Might be useful to know im going off Swiftless's OpenGL 4 GLSL tutorials so I'm using glm and glew.

Also I use glBindAttribute to always pass the vertices position as a vec3 and to pass the tex coords as a vec2 into my Shader program(the same way i passed verts, color and normals earlier)

Any way heres some code:

This generates my VAO from 2 VBO's, one fro my verts and the other tex coords.
glGenVertexArrays(1, &vaoID); glBindVertexArray(vaoID); glGenBuffers(2, &vboID[0]); //Verticies glBindBuffer(GL_ARRAY_BUFFER, vboID[0]); glBufferData(GL_ARRAY_BUFFER, 108 * sizeof(GLfloat), v, GL_STATIC_DRAW); glVertexAttribPointer((GLuint)0, 3, GL_FLOAT, GL_FALSE, 0, 0); glEnableVertexAttribArray(0); //Tex Coords glBindBuffer(GL_ARRAY_BUFFER, vboID[1]); glBufferData(GL_ARRAY_BUFFER, 72 * sizeof(GLfloat), t, GL_STATIC_DRAW); glVertexAttribPointer((GLuint)1, 2, GL_FLOAT, GL_FALSE, 0, 0); glEnableVertexAttribArray(1); glBindVertexArray(0);

Then I draw the cube like so:
 shader->bind(); int projectionMatrixLocation = glGetUniformLocation(shader->id(), "projectionMatrix"); int viewMatrixLocation = glGetUniformLocation(shader->id(), "viewMatrix"); int modelMatrixLocation = glGetUniformLocation(shader->id(), "modelMatrix"); int texture_location = glGetUniformLocation(shader->id(), "texture_color"); glUniformMatrix4fv(projectionMatrixLocation, 1, GL_FALSE, &projectionMatrix[0][0]); glUniformMatrix4fv(viewMatrixLocation, 1, GL_FALSE, &viewMatrix[0][0]); glUniformMatrix4fv(modelMatrixLocation, 1, GL_FALSE, &modelMatrix[0][0]); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glUniform1i(texture_location, 0); glBindVertexArray(vaoID); glDrawArrays(GL_TRIANGLES, 0, 36); glBindVertexArray(0); shader->unbind(); 

...and my Vertex and Pixel(fragment) shaders respectivley:
 #version 150 core uniform mat4 projectionMatrix; uniform mat4 viewMatrix; uniform mat4 modelMatrix; in vec3 in_Position; in vec2 in_TexCoord; void main(void){ gl_TexCoord[0] = in_TexCoord; gl_Position = projectionMatrix * viewMatrix * modelMatrix * vec4(in_Position, 1.0); } 

 #version 150 core uniform sampler2D texture_color; void main(void){ gl_FragColor = texture2D(texture_color, gl_TexCoord[0].st); } 
The result is a white cube that seems to lose its scaleing compared to when I specify a solid gl_FragColor

My assumtion is something to do with gl_TexCoord[0] not being a vec2 like in_TexCoord but I can't seem to find much/any documentaion on GLSL when using custom arrays for everything. All the examples I've seen use gl_MultiTexCoord[0] to pull the tex coords from the now depriciated glMultiTexCoordxx()... I think .
I can post the vertex and tex coords initialization routine if that would help but its alot of crap lol.
I apologize if I'm not giving enough info or too much lol. I greatly appreciate any help given!!

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I'm not sure about the gl_TexCoord[0] issue, but I would suggest just to define your own varying texcoord variable and not use the builtin one. Are you checking shaders and programs for compile errors?

You said you're using glBindAttribute, do you mean glBindAttribLocation?

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If you read Swiftless, he says:

In GLSL 1.50, we no longer have gl_ModelViewMatrix, gl_ProjectionMatrix, gl_Vertex, etc, etc[/quote] So it appears you cannot use the built-in texture coordinate array. Declare your own varying vec2 variable, set it to the attribute texture coordinate in the vertex shader, and feed it to the fragment shader. Also, don't use the built-in fragment color variable. Declare your own vec4. Something like this:

 #version 150 core uniform mat4 projectionMatrix; uniform mat4 viewMatrix; uniform mat4 modelMatrix; in vec3 in_Position; in vec2 in_TexCoord; out vec2 out_TexCoord; void main(void){ out_TexCoord = in_TexCoord; gl_Position = projectionMatrix * viewMatrix * modelMatrix * vec4(in_Position, 1.0); } 

 #version 150 core in vec2 out_TexCoord; uniform sampler2D texture_color; out vec4 FragColor; void main(void){ FragColor = texture2D(texture_color, out_TexCoord.st); }

If that doesn't work, check the stuff that Karwosts mentioned above.

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@karwosts - Yes I meant glBindAttribLocation, sorry I had literally been up all night working with the new GL specification and It was starting to hurt my brain lol.

Okay I dropped the usage of gl_TexCoord[0] and did as Jesse7 suggested but that still didn't work, although not because it's incorrect. The issue seems to be the texture loader I have been using all the time from all my intermediate mode stuff. Not sure what was wrong with it but replaceing it with Swiftless's RAW texture loader code and doing the things Jesse7 suggested worked like a charm. It may be worth noteing that in the fragment shader the line:
FragColor = texture2D(texture_color, out_TexCoord.st);

You don't need the .st at the end of our varying vec2 out_TexCoord, or at least it works without it. What is the purpose of the .st at the end of a vec2 varialbe?
Anyways I hate the RAW format so I guess it's time to write my own Targa loader.
Thank you all for your help!

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What is the purpose of the .st at the end of a vec2 varialbe?
Anyways I hate the RAW format so I guess it's time to write my own Targa loader.
I guess .st is redundant since we have a vec2. For loading Targas and a slew of other formats, you could use FreeImage or DevIL. SOIL is another one but it doesn't seem to work with a core profile.

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Well I had been using a pretty good Targa loader for a while and had even adapted the code to load my own height maps. Although I now have figured out why my texture loader wasn't working In the first place. I tried replaceing the filtering on the RAW texture loader to use mipmaps and used gluBuild2DMipmaps(); but as soon as I ran it resulted in the same black cube. So my old texture loader that also used mipmaps was wrong due to this. I've looked around a bit about GLSL mipmaping and found the command texture2dLod(); So I'm going to persue that route at some point.

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I tried replaceing the filtering on the RAW texture loader to use mipmaps and used gluBuild2DMipmaps(); but as soon as I ran it resulted in the same black cube. So my old texture loader that also used mipmaps was wrong due to this. I've looked around a bit about GLSL mipmaping and found the command texture2dLod(); So I'm going to persue that route at some point.
Yeah, if you use deprecated code with a core profile you sometimes get weird stuff like black textures . I don't much about that GLSL command, but another way of generating mipmaps is by calling glGenerateMipmap () right after you load the texture:
 // use trilinear filtering glBindTexture(GL_TEXTURE_2D, textureId); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); glTexParameteri( GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER, GL_LINEAR ); glTexImage2D(GL_TEXTURE_2D,0,GL_RGBA, w, h, 0, GL_RGBA,GL_UNSIGNED_BYTE,pixels); // generate mipmaps glGenerateMipmap(GL_TEXTURE_2D);