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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

This topic is 402 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

## Recommended Posts

I have implemented the depthmap and have gotten it to render the depthmap.

The problem I am having is when implementing the shadows. Now since this is part of a bigger project that uses Deferred Rendering, the code does not match the code in the tutorial but I am using the same concept.

#version 440
layout (location = 0) in vec3 vertexPos;
layout (location = 1) in vec2 texCoords;

out vec2 TexCoords;
out vec4 FragPosLightSpace;

uniform mat4 model;
uniform sampler2D gPosition;
uniform mat4 lightSpaceMatrix;

void main()
{
gl_Position = vec4(vertexPos, 1.0f);
TexCoords = texCoords;
vec3 FragmentPos = vec3(model * texture(gPosition, texCoords));
FragPosLightSpace = lightSpaceMatrix * vec4(FragmentPos, 1.0);
}

#version 440
out vec4 FragColor;
in vec2 TexCoords;
in vec4 FragPosLightSpace;

uniform sampler2D gPosition;
uniform sampler2D gNormal;
uniform sampler2D gAlbedoSpec;
uniform sampler2D depthMap;

struct Light {
vec3 Position;
vec3 Color;

float Linear;
};

const int NR_LIGHTS = 32;
uniform Light lights[NR_LIGHTS];
uniform vec3 viewPos;

{
//Perform perspective divide
vec3 projCoords = fragPosLightSpace.xyz / fragPosLightSpace.w;
//Transform to [0,1] range
projCoords = projCoords * 0.5 + 0.5;
//Get closest depth value from light's perspective (using [0,1] range fragPosLight as coords)
float closestDepth = texture(depthMap, projCoords.xy).r;
//Get depth of current fragment from light's perspective
float currentDepth = projCoords.z;
//Check wheter current frag pos is in shadow
if(currentDepth > closestDepth)
{
}

}

void main()
{
// Retrieve data from G-buffer
vec3 FragPos = texture(gPosition, TexCoords).rgb;
vec3 Normal = texture(gNormal, TexCoords).rgb;
vec3 color = texture(gAlbedoSpec, TexCoords).rgb;
float Specular = texture(gAlbedoSpec, TexCoords).a;

vec3 viewDir = normalize(viewPos - FragPos);
for(int i = 0; i < NR_LIGHTS; ++i)
{
vec3 lightDir = normalize(lights[i].Position - FragPos);
vec3 diffuse = max(dot(Normal, lightDir), 0.0) * color * lights[i].Color;
// Specular
vec3 halfwayDir = normalize(lightDir + viewDir);
float spec = pow(max(dot(Normal, halfwayDir), 0.0), 16.0);
vec3 specular = lights[i].Color * spec * Specular;
// Attenuation
float distance = length(lights[i].Position - FragPos);
float attenuation = 1.0 / (1.0 + lights[i].Linear * distance + lights[i].Quadratic * distance * distance);
diffuse *= attenuation;
specular *= attenuation;
lighting += diffuse + specular;
}
lighting * color;
FragColor = vec4(lighting, 1.0f);
float depthValue = texture(depthMap,TexCoords).r;
// Test depthmap
//FragColor = vec4(vec3(depthValue),1.0);
}

The ShadowCalculation is the function that calculates if a position is in shadows or not. And it pretty much follows the same concept as the tutorial does.

Now if I run all this, all I get is a white screen, I thought it might be because I had the setting of shadow wrong so I tried setting float shadow = 1.0 and then in the if-statement setting shadows to 0.0. Now I dont get a completly white screen but the shadows are not showing. I feel like I am close to a solution but have kinda gotten stuck right now and would appreciate if someone could tell me what the problem is or could be.

Edited by ChobitsTheZero

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The shadow map is supposed to be a depth map, but you're taking vectors out of it in the vertex shader... using completely unrelated texture coordinates, no less, this doesn't make any sense whatsoever.

You could think of the shadow map texture as a lookup table for ray tracing the primary light rays, i.e. the ray between the fragment position and the light source. You will basically have to transform the fragment two different ways, for two different "cameras" to get the values you need to do this calculation. One of the cameras represents the main display, and the other represents the light. The light camera was previously used to create the depth map, in which each texel represents a single ray of light, and the depth value is the distance a light ray can travel before it gets obstructed. To perform the shadow calculation, you will test if the distance traveled by the light is shorter than the actual distance to the fragment that's being shaded, to determine if the light is obstructed before it reaches the fragment in question.

Thus, your vertex shader shouldn't do texture lookups, it should just output the position of the vertex in lightspace, i.e. lightSpaceMatrix * vec4(vertexPos, 1)

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The shadow map is supposed to be a depth map, but you're taking vectors out of it in the vertex shader... using completely unrelated texture coordinates, no less, this doesn't make any sense whatsoever.

You could think of the shadow map texture as a lookup table for ray tracing the primary light rays, i.e. the ray between the fragment position and the light source. You will basically have to transform the fragment two different ways, for two different "cameras" to get the values you need to do this calculation. One of the cameras represents the main display, and the other represents the light. The light camera was previously used to create the depth map, in which each texel represents a single ray of light, and the depth value is the distance a light ray can travel before it gets obstructed. To perform the shadow calculation, you will test if the distance traveled by the light is shorter than the actual distance to the fragment that's being shaded, to determine if the light is obstructed before it reaches the fragment in question.

Thus, your vertex shader shouldn't do texture lookups, it should just output the position of the vertex in lightspace, i.e. lightSpaceMatrix * vec4(vertexPos, 1)

I see! That really helps! I have kinda been short on time and really stressed due to exams so I basically has to rush through it all. But I shouldn't try to make excuses, I guess i'm just bad at understanding how excatly 3D programming works.

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Okey so, I did what you said but it seems that there is also another problem which I can't really figure out what it is. So now there are shadows, but they dont seem to be at the correct position. Instead of being behind the models they are instead infront of them and slightly above them. I was thinking that maybe I had to multiple the vec4(vertexPos, 1) with model, but that also gave a weird result.

#Edit: Nevermind I was able to solve it, appearantly the lightspacematrix had some issues with it.

Edited by ChobitsTheZero