• Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • 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!
  • Advertisement
  • Advertisement
Sign in to follow this  

OpenGL Optimizing OpenGL FPS

This topic is 886 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi

 looking at this:

I wonder what they still need to optimize on Linux, espcially for use with the upcoming SteamVR.

I've used OpenGL a very little bit on the three main os, but never that much to run into such FPS differences.

Nvidia on Linux should be as fast as on Windows, X-Plane for ex. runs 20% faster with my GTX770 on Ubuntu.

Thanks for feedback, links and ideas to broaden my horizon.

 

Share this post


Link to post
Share on other sites
Advertisement

I've used OpenGL a very little bit on the three main os, but never that much to run into such FPS differences.

Nvidia on Linux should be as fast as on Windows, X-Plane for ex. runs 20% faster with my GTX770 on Ubuntu.

 

This is called proof by example.

 

Game systems are complex. Yours or X-Plane's cases may not stress the same usage scenarios as Alien Isolation does. It could be difference in performance in a feature that has an easy marketed label attachable to it ("oh, it's geometry shaders that are slower", or "oh, tessellation is this much slower") which can be easy to attribute to layman terms, or it might as well not, and it could just be about some internal API call access patterns that a specific engine or a new fancy rendering technique might need to use.

 

What is causing the actual slowdown in this specific case, your guess is as good as anyone else's, and the only way to know is if you could ask the first-hand developers who have access to the code and have profiled the game on multiple platforms.

Share this post


Link to post
Share on other sites


Nvidia on Linux should be as fast as on Windows


Expectation is one thing, but reality is another. Linux and Windows are 2 different operating system with different driver models and other underlying technology that the GPU driver depends on. So there are a multitude of issues that could cause significant differences between any OS and not as simple as, its the same hardware.

Share this post


Link to post
Share on other sites
This could also be Windows D3D vs Linux GL performance.

Different engine renderer, different API, different drivers, different calling patterns, different shader language, different OS.

I would expect that any D3D->GL port would be initially slower, before all the GL workarounds are added in.

Share this post


Link to post
Share on other sites

Yes, probably a dual core, as used in that test, is not enough as one thread alone is needed for hlsl -> glsl conversion?

 

Found out that in Steam settings you can show FPS on Linux. My GTX770 with a i7 and all settings maxed is always above 100FPS with Alien Isolation.

Edited by FGFS

Share this post


Link to post
Share on other sites

Yes, probably a dual core, as used in that test, is not enough as one thread alone is needed for hlsl -> glsl conversion?


This should be one-time-only and at startup/load.  If HLSL is being converted to GLSL at runtime then the developers have done something insane, stupid or malicious.

Share this post


Link to post
Share on other sites

A dualcore seems way outdated for game tests to me. For ex. if you would try X-Plane with a dualcore it would hardly run at all on all os. As X-Plane performs best on Linux, I'm way surprised to see such. The porting was done by a Mac company hence no wonder it needs a multicore.

 

PS: yes it fully uses all 8 cores hence I'm not surprised about such FPS on a dated dualcore

Even a i3 is mentioned as minium in the specs and this ridi* arstecnica gaming test site uses a dualcore!

Edited by FGFS

Share this post


Link to post
Share on other sites

A dualcore seems way outdated for game tests to me. For ex. if you would try X-Plane with a dualcore it would hardly run at all on all os. As X-Plane performs best on Linux, I'm way surprised to see such. The porting was done by a Mac company hence no wonder it needs a multicore.

 

PS: yes it fully uses all 8 cores hence I'm not surprised about such FPS on a dated dualcore

Even a i3 is mentioned as minium in the specs and this ridi* arstecnica gaming test site uses a dualcore!

 

The article does acknowledge this:

 

 

The hardware on that bare bones machine is a little out of date now, but since that hardware is remaining static for both sides of the test, it should suffice for giving an idea of the relative performance between the operating systems.

 

You should note that what we're talking about here is a comparison between two operating systems.  For this kind of test it seems to me that making the test be CPU-bound is what you actually want to do.  Otherwise you'll get pretty much identical results from the same GPU hardware, which would be a meaningless outcome.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement