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    • 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!
    • By Jens Eckervogt
      Hello guys, 
       
      Please tell me! 
      How do I know? Why does wavefront not show for me?
      I already checked I have non errors yet.
      using OpenTK; using System.Collections.Generic; using System.IO; using System.Text; namespace Tutorial_08.net.sourceskyboxer { public class WaveFrontLoader { private static List<Vector3> inPositions; private static List<Vector2> inTexcoords; private static List<Vector3> inNormals; private static List<float> positions; private static List<float> texcoords; private static List<int> indices; public static RawModel LoadObjModel(string filename, Loader loader) { inPositions = new List<Vector3>(); inTexcoords = new List<Vector2>(); inNormals = new List<Vector3>(); positions = new List<float>(); texcoords = new List<float>(); indices = new List<int>(); int nextIdx = 0; using (var reader = new StreamReader(File.Open("Contents/" + filename + ".obj", FileMode.Open), Encoding.UTF8)) { string line = reader.ReadLine(); int i = reader.Read(); while (true) { string[] currentLine = line.Split(); if (currentLine[0] == "v") { Vector3 pos = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inPositions.Add(pos); if (currentLine[1] == "t") { Vector2 tex = new Vector2(float.Parse(currentLine[1]), float.Parse(currentLine[2])); inTexcoords.Add(tex); } if (currentLine[1] == "n") { Vector3 nom = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inNormals.Add(nom); } } if (currentLine[0] == "f") { Vector3 pos = inPositions[0]; positions.Add(pos.X); positions.Add(pos.Y); positions.Add(pos.Z); Vector2 tc = inTexcoords[0]; texcoords.Add(tc.X); texcoords.Add(tc.Y); indices.Add(nextIdx); ++nextIdx; } reader.Close(); return loader.loadToVAO(positions.ToArray(), texcoords.ToArray(), indices.ToArray()); } } } } } And It have tried other method but it can't show for me.  I am mad now. Because any OpenTK developers won't help me.
      Please help me how do I fix.

      And my download (mega.nz) should it is original but I tried no success...
      - Add blend source and png file here I have tried tried,.....  
       
      PS: Why is our community not active? I wait very longer. Stop to lie me!
      Thanks !
    • By codelyoko373
      I wasn't sure if this would be the right place for a topic like this so sorry if it isn't.
      I'm currently working on a project for Uni using FreeGLUT to make a simple solar system simulation. I've got to the point where I've implemented all the planets and have used a Scene Graph to link them all together. The issue I'm having with now though is basically the planets and moons orbit correctly at their own orbit speeds.
      I'm not really experienced with using matrices for stuff like this so It's likely why I can't figure out how exactly to get it working. This is where I'm applying the transformation matrices, as well as pushing and popping them. This is within the Render function that every planet including the sun and moons will have and run.
      if (tag != "Sun") { glRotatef(orbitAngle, orbitRotation.X, orbitRotation.Y, orbitRotation.Z); } glPushMatrix(); glTranslatef(position.X, position.Y, position.Z); glRotatef(rotationAngle, rotation.X, rotation.Y, rotation.Z); glScalef(scale.X, scale.Y, scale.Z); glDrawElements(GL_TRIANGLES, mesh->indiceCount, GL_UNSIGNED_SHORT, mesh->indices); if (tag != "Sun") { glPopMatrix(); } The "If(tag != "Sun")" parts are my attempts are getting the planets to orbit correctly though it likely isn't the way I'm meant to be doing it. So I was wondering if someone would be able to help me? As I really don't have an idea on what I would do to get it working. Using the if statement is truthfully the closest I've got to it working but there are still weird effects like the planets orbiting faster then they should depending on the number of planets actually be updated/rendered.
    • By Jens Eckervogt
      Hello everyone, 
      I have problem with texture
      using System; using OpenTK; using OpenTK.Input; using OpenTK.Graphics; using OpenTK.Graphics.OpenGL4; using System.Drawing; using System.Reflection; namespace Tutorial_05 { class Game : GameWindow { private static int WIDTH = 1200; private static int HEIGHT = 720; private static KeyboardState keyState; private int vaoID; private int vboID; private int iboID; private Vector3[] vertices = { new Vector3(-0.5f, 0.5f, 0.0f), // V0 new Vector3(-0.5f, -0.5f, 0.0f), // V1 new Vector3(0.5f, -0.5f, 0.0f), // V2 new Vector3(0.5f, 0.5f, 0.0f) // V3 }; private Vector2[] texcoords = { new Vector2(0, 0), new Vector2(0, 1), new Vector2(1, 1), new Vector2(1, 0) }; private int[] indices = { 0, 1, 3, 3, 1, 2 }; private string vertsrc = @"#version 450 core in vec3 position; in vec2 textureCoords; out vec2 pass_textureCoords; void main(void) { gl_Position = vec4(position, 1.0); pass_textureCoords = textureCoords; }"; private string fragsrc = @"#version 450 core in vec2 pass_textureCoords; out vec4 out_color; uniform sampler2D textureSampler; void main(void) { out_color = texture(textureSampler, pass_textureCoords); }"; private int programID; private int vertexShaderID; private int fragmentShaderID; private int textureID; private Bitmap texsrc; public Game() : base(WIDTH, HEIGHT, GraphicsMode.Default, "Tutorial 05 - Texturing", GameWindowFlags.Default, DisplayDevice.Default, 4, 5, GraphicsContextFlags.Default) { } protected override void OnLoad(EventArgs e) { base.OnLoad(e); CursorVisible = true; GL.GenVertexArrays(1, out vaoID); GL.BindVertexArray(vaoID); GL.GenBuffers(1, out vboID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(vertices.Length * Vector3.SizeInBytes), vertices, BufferUsageHint.StaticDraw); GL.GenBuffers(1, out iboID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(int)), indices, BufferUsageHint.StaticDraw); vertexShaderID = GL.CreateShader(ShaderType.VertexShader); GL.ShaderSource(vertexShaderID, vertsrc); GL.CompileShader(vertexShaderID); fragmentShaderID = GL.CreateShader(ShaderType.FragmentShader); GL.ShaderSource(fragmentShaderID, fragsrc); GL.CompileShader(fragmentShaderID); programID = GL.CreateProgram(); GL.AttachShader(programID, vertexShaderID); GL.AttachShader(programID, fragmentShaderID); GL.LinkProgram(programID); // Loading texture from embedded resource texsrc = new Bitmap(Assembly.GetEntryAssembly().GetManifestResourceStream("Tutorial_05.example.png")); textureID = GL.GenTexture(); GL.BindTexture(TextureTarget.Texture2D, textureID); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)All.Linear); GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)All.Linear); GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba, texsrc.Width, texsrc.Height, 0, PixelFormat.Bgra, PixelType.UnsignedByte, IntPtr.Zero); System.Drawing.Imaging.BitmapData bitmap_data = texsrc.LockBits(new Rectangle(0, 0, texsrc.Width, texsrc.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb); GL.TexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, texsrc.Width, texsrc.Height, PixelFormat.Bgra, PixelType.UnsignedByte, bitmap_data.Scan0); texsrc.UnlockBits(bitmap_data); GL.Enable(EnableCap.Texture2D); GL.BufferData(BufferTarget.TextureBuffer, (IntPtr)(texcoords.Length * Vector2.SizeInBytes), texcoords, BufferUsageHint.StaticDraw); GL.BindAttribLocation(programID, 0, "position"); GL.BindAttribLocation(programID, 1, "textureCoords"); } protected override void OnResize(EventArgs e) { base.OnResize(e); GL.Viewport(0, 0, ClientRectangle.Width, ClientRectangle.Height); } protected override void OnUpdateFrame(FrameEventArgs e) { base.OnUpdateFrame(e); keyState = Keyboard.GetState(); if (keyState.IsKeyDown(Key.Escape)) { Exit(); } } protected override void OnRenderFrame(FrameEventArgs e) { base.OnRenderFrame(e); // Prepare for background GL.Clear(ClearBufferMask.ColorBufferBit); GL.ClearColor(Color4.Red); // Draw traingles GL.EnableVertexAttribArray(0); GL.EnableVertexAttribArray(1); GL.BindVertexArray(vaoID); GL.UseProgram(programID); GL.BindBuffer(BufferTarget.ArrayBuffer, vboID); GL.VertexAttribPointer(0, 3, VertexAttribPointerType.Float, false, 0, IntPtr.Zero); GL.ActiveTexture(TextureUnit.Texture0); GL.BindTexture(TextureTarget.Texture3D, textureID); GL.BindBuffer(BufferTarget.ElementArrayBuffer, iboID); GL.DrawElements(BeginMode.Triangles, indices.Length, DrawElementsType.UnsignedInt, 0); GL.DisableVertexAttribArray(0); GL.DisableVertexAttribArray(1); SwapBuffers(); } protected override void OnClosed(EventArgs e) { base.OnClosed(e); GL.DeleteVertexArray(vaoID); GL.DeleteBuffer(vboID); } } } I can not remember where do I add GL.Uniform2();
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OpenGL trouble getting started

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So I'm giving OpenGL another shot, after approx. 1 year without touching it at all and never having got very far into it to begin with. My choice of starting point was NeHe's tutorials and the first tutorial went off without a hitch. The second lesson, however, is giving me a bit of trouble. It still compiles and runs fine, but nothing new is displayed. I added the code for drawing a triangle and a quad, but nothing shows up. I followed the tutorial exactly, so I don't know what's going on. Does anyone have any suggesstions? I'll provide code on request, but seeing as it's already on the NeHe site, it doesn't seem appropriate at this time. Thanks.

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Well, the first thing I'd do is make sure that your OpenGL application is correctly set up with Windows/WinAPI.
So basically, make sure you have a valid OpenGL rendering context.

When you know OpenGL is set up correctly, you should make sure your projection/modelview matrices are correct.

If you are using GLU, then to get correct matrices all you have to do is this:


glMatrixMode(GL_PROJECTION);
glLoadIdentity();

gluPerspective(field_of_view, screen_width / screen_height, near_plane, far_plane);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();



When you have your identity matrix loaded (or basically, the view of the world is reset), the camera is looking down the Z axis, which is <0.0, 0.0, -1.0>.
That way, you can render a basic quad with a common Z value of -10.0, and it will be visible without changing your camera orientation.


glBegin(GL_QUADS);
glVertex3f(-1.0f, -1.0f, -10.0f);
glVertex3f(1.0f, -1.0f, -10.0f);
glVertex3f(1.0f, 1.0f, -10.0f);
glVertex3f(-1.0f, 1.0f, -10.0f);
glEnd();



Here's a minimal complete application which shows a rotating quad.


#define SCREEN_WIDTH 1024
#define SCREEN_HEIGHT 768
#define BITSPERPIXEL 32
#define DEPTHBUFFER_PRES 24

#include <windows.h>
#include <gl/gl.h>
#include <gl/glu.h>

HWND hWnd;
HDC hDC;
HGLRC hRC;

/****************************************************************************************

Window procedure (WinAPI)

*****************************************************************************************/

LRESULT CALLBACK WndProc (HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK WndProc (HWND hWnd, UINT message,
WPARAM wParam, LPARAM lParam)
{

switch (message)
{
case WM_CLOSE:
PostQuitMessage (0);
return 0;

case WM_KEYDOWN:

//If ESC is pressed, close the application.
if (wParam == VK_ESCAPE)
{
PostQuitMessage(0);
return 0;
}

return 0;
default:
return DefWindowProc (hWnd, message, wParam, lParam);
}
}

int WINAPI WinMain (HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int iCmdShow)
{
/****************************************************************************************

Open up a window

*****************************************************************************************/

WNDCLASSEX wc;
PIXELFORMATDESCRIPTOR pfd;
int f = 0;

//Register window class
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_OWNDC;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor (NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH) GetStockObject (BLACK_BRUSH);
wc.lpszMenuName = NULL;
wc.lpszClassName = "FSWindow";
wc.hIconSm = LoadIcon(NULL, IDI_WINLOGO);
RegisterClassEx(&wc);

//Enable fullscreen
DEVMODE dmScreenSettings;
ZeroMemory (&dmScreenSettings, sizeof (DEVMODE));
dmScreenSettings.dmSize = sizeof (DEVMODE);
dmScreenSettings.dmPelsWidth = SCREEN_WIDTH;
dmScreenSettings.dmPelsHeight = SCREEN_HEIGHT;
dmScreenSettings.dmBitsPerPel = BITSPERPIXEL;
dmScreenSettings.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
ChangeDisplaySettings(&dmScreenSettings, CDS_FULLSCREEN);
RECT windowRect = {0, 0, SCREEN_WIDTH, SCREEN_HEIGHT};
AdjustWindowRectEx (&windowRect, WS_POPUP, 0, WS_EX_APPWINDOW | WS_EX_TOPMOST);



//Open window
hWnd = CreateWindowEx(WS_EX_APPWINDOW | WS_EX_TOPMOST,
"FSWindow",
"Test window",
WS_POPUP,
0, 0,
SCREEN_WIDTH,
SCREEN_HEIGHT,
HWND_DESKTOP,
NULL,
hInstance,
NULL);

//Show the window
ShowWindow(hWnd, SW_NORMAL);






/****************************************************************************************

Create rendering context for OpenGL

*****************************************************************************************/

hDC = GetDC(hWnd);

//Setup pixelformat on the device context
memset(&pfd, 0, sizeof(pfd));

pfd.nSize = sizeof(pfd);
pfd.nVersion = 1;
pfd.dwFlags = PFD_DRAW_TO_WINDOW |
PFD_SUPPORT_OPENGL |
PFD_DOUBLEBUFFER;
pfd.iPixelType = PFD_TYPE_RGBA;
pfd.cColorBits = BITSPERPIXEL;
pfd.cDepthBits = DEPTHBUFFER_PRES;
pfd.iLayerType = PFD_MAIN_PLANE;

f = ChoosePixelFormat(hDC, &pfd);
SetPixelFormat(hDC, f, &pfd);

//Create and enable rendering context
hRC = wglCreateContext(hDC);
wglMakeCurrent(hDC, hRC);






/****************************************************************************************

Set up OpenGL

*****************************************************************************************/


// Set up matrices
float field_of_view = 45.0f;
float screen_width = SCREEN_WIDTH;
float screen_height = SCREEN_HEIGHT;
float near_plane = 1.0f;
float far_plane = 100.0f;

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(field_of_view, screen_width / screen_height, near_plane, far_plane);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();








/****************************************************************************************

Main loop

*****************************************************************************************/

bool quit = false;
float rot = 0.0f;
MSG msg;

while (quit == false)
{
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
if (msg.message == WM_QUIT)
{
quit = TRUE;
}
else
{
TranslateMessage (&msg);
DispatchMessage (&msg);
}
}

//Clear backbuffer and reset camera
glClear(GL_COLOR_BUFFER_BIT);
glLoadIdentity();

//Rotate around Z axis
rot += 0.001f;
glRotatef(rot, 0, 0, 1);

//Draw quad
glBegin(GL_QUADS);
glColor3f(1.0f, 0.0f, 0.0f);
glVertex3f(-1.0f, -1.0f, -10.0f);

glColor3f(0.0f, 1.0f, 0.0f);
glVertex3f(1.0f, -1.0f, -10.0f);

glColor3f(0.0f, 0.0f, 1.0f);
glVertex3f(1.0f, 1.0f, -10.0f);

glColor3f(1.0f, 0.0f, 1.0f);
glVertex3f(-1.0f, 1.0f, -10.0f);
glEnd();

//Show what we have drawn to the screen
SwapBuffers(hDC);
}



/****************************************************************************************

Close application

*****************************************************************************************/

wglMakeCurrent(NULL, NULL);
wglDeleteContext(hRC);

ReleaseDC(hWnd, hDC);
DestroyWindow(hWnd);
ChangeDisplaySettings(NULL, 0);
UnregisterClass("FSWindow", hInstance);
}

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Thanks for the reply and the assistance. I got it working and am continuing through the lessons without too much trouble. Thanks.

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