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      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!
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      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.
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    • 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();
    • By Jens Eckervogt
      Hello everyone
      For @80bserver8 nice job - I have found Google search. How did you port from Javascript WebGL to C# OpenTK.?
      I have been searched Google but it shows f***ing Unity 3D. I really want know how do I understand I want start with OpenTK But I want know where is porting of Javascript and C#?
       
      Thanks!
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OpenGL Coordinate System problem w/ Ortho & View Matrices and GL.Viewport

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Hello, I've been in the process of getting my OpenGL ES 2.0 application setup to render correctly. I'm currently just trying to draw simple lines to verify that my coordinate system is setup correctly. I'm also using Xamarin w/ their provided OpenGLView that provides a cross platform opengl context with OpenTK.

However, once I introduced GL.Viewport, a orthographic projection matrix and a view matrix I am unable to get any simple lines to display. Before I introduced these pieces I was able to get lines to display, however they weren't at the desired coordinates, which is what led me to using GL.Viewport and the matrices. I've tried setting my view matrix to look down the positive or negative z-axis, nixed the view matrix all together, different multiplication ordering for the mvpMatrix, as well as removing the use of GL.Viewport. Also, different z-values for the verts of the lines. I am doing something wrong, and I am not sure what.

This is my OpenGL initialization code, w/ my ShaderProgram setup for my verts buffer object and model view projection matrix:

Matrix4 m_projMatrix, m_viewMatrix, m_mvpMatrix;
int m_vpWidth, m_vpHeight;
// Vertex Buffer Data
float[] verts = { 0, 0, 1,
                  100, 100, 1};

private void InitOpengl(int width, int height)
{
  GL.Enable(EnableCap.DepthTest);

  m_vpWidth  = width;
  m_vpHeight = height;
  float ratio = (float)width / height;
      
  m_projMatrix = Matrix4.CreateOrthographic(m_vpWidth, m_vpHeight, 1f, 100f);
  m_viewMatrix = Matrix4.LookAt(Vector3.UnitZ, Vector3.Zero, Vector3.UnitY);
  m_mvpMatrix = m_projMatrix * m_viewMatrix;// Matrix4.Mult(m_viewMatrix, m_projMatrix);
  //m_mvpMatrix  = Matrix4.Mult(m_mvpMatrix, Matrix4.CreateRotationY(0));

  m_shaderPrograms = new ArrayList();

  string vertexLineShaderSrc = 
    @"attribute vec3 vertex_position;
    uniform mat4 mvp;
    void main()
    {
      gl_Position = mvp * vec4(vertex_position, 1.0);
    }";
  string fragLineShaderSrc =
    @"void main()
    {
      gl_FragColor = vec4(0.0, 1.0, 0.0, 1.0);
    }";

  ShaderProgram lineShader = ShaderProgram.CreateShaderProgram(vertexLineShaderSrc, fragLineShaderSrc, () => { GL.DrawArrays(BeginMode.Lines, 0, verts.Length); });
  if (lineShader != null)
  {
    lineShader.AddAttributeLocationData(new AttributeLocationData(lineShader.ShaderProgramId,
      "vertex_position",
      () =>
      {
        int vertexPosAttrib = GL.GetAttribLocation(lineShader.ShaderProgramId, "vertex_position");
        GL.EnableVertexAttribArray(vertexPosAttrib);
        GL.VertexAttribPointer(vertexPosAttrib, 3, VertexAttribPointerType.Float, false, 0, verts);
      }));
    lineShader.AddUniformLocationData(new UniformLocationData(lineShader.ShaderProgramId,
      "mvp",
      () =>
      {
        int mvpUniform = GL.GetUniformLocation(lineShader.ShaderProgramId, "mvp");
        GL.UniformMatrix4(mvpUniform, false, ref m_mvpMatrix);
      }));
    m_shaderPrograms.Add(lineShader);
  }
}

This is my OpenGLView initialization and render code:

m_ogl = new OpenGLView();
m_ogl.HeightRequest = Forms.Context.Resources.DisplayMetrics.HeightPixels;
m_ogl.WidthRequest  = Forms.Context.Resources.DisplayMetrics.WidthPixels;
m_ogl.HasRenderLoop = true;

m_ogl.OnDisplay = (r) =>
{
  if (!m_init)
  {
    InitOpengl((int)m_ogl.HeightRequest, (int)m_ogl.WidthRequest);
    m_init = true;
  }

  GL.ClearColor(System.Drawing.Color.CornflowerBlue);
  GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
  GL.Viewport(0, 0, m_vpWidth, m_vpHeight);

  float ratio = (float)m_vpWidth / m_vpHeight;
  m_projMatrix = Matrix4.CreateOrthographic(m_vpWidth, m_vpHeight, 0, 100);
  m_viewMatrix = Matrix4.LookAt(Vector3.UnitZ, Vector3.Zero, Vector3.UnitY);
  m_mvpMatrix = m_projMatrix * m_viewMatrix;
  //Vector4 value = Vector4.Transform(new Vector4(0, 0, 0, 1), m_mvpMatrix);

  foreach (ShaderProgram shader in m_shaderPrograms)
  {
    GL.UseProgram(shader.ShaderProgramId);
    shader.CallAttributeLocationDataFuncs();
    shader.CallUniformLocationDataFuncs();
    shader.ShaderUseFunc();
    GL.Finish();
  }
};

All I want to do is draw a line from the bottom left of my screen to somewhere in the top right, which is correctly projected into NDC [-1,-1] -> [1,1]

Thank you very much for any insight.

Edited by m11hut

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When I change my render code to be just:

GL.ClearColor(System.Drawing.Color.CornflowerBlue);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
//GL.Viewport(0, 0, m_vpWidth, m_vpHeight);
        
float ratio = (float)m_vpWidth / m_vpHeight;
m_projMatrix = Matrix4.CreateOrthographicOffCenter(-ratio, ratio, -1f, 1f, -1f, 1f);
m_viewMatrix = Matrix4.LookAt(Vector3.UnitZ, Vector3.Zero, Vector3.UnitY);
m_mvpMatrix  = m_projMatrix * m_viewMatrix;

I do get lines to draw, but the coordinate system makes absolutely no sense. (0,0) appears to be the middle center of the device. I also changed my verts[] to be: (0, 0, 0) and (1,1, 0). Where the (1, 1) seems to go off somewhere to the top right. I don't have any idea why this is not working as expected, and it doesn't make any sense.

The only thing I can think of is the Xamarin.Forms.OpenGLView is doing something behind the scenes.

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I'm a little confused about the confusion.  So you are saying that when you send down a vertex at ( 0, 0 ) it is showing up in the center of the device and you want it to show up in the lower left of the device ?

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m_projMatrix = Matrix4.CreateOrthographicOffCenter(-ratio, ratio, -1f, 1f, -1f, 1f);

What this is doing is that it's scaling and moving [left, right] range so that it fits the left to right of you device meaning in the NDC you will have that range normalized to [-1, 1], and it's also moving and scaling [bottom, top] range to fit the bottom and top of the device, normalizing it to [-1, 1] range in NDC which in your case it already is.

As the both ranges are centered at 0, just like the NDC ranges, there is no need for moving, so it's just scaling the ranges to fid the NDC, that's why (0, 0, 0) is at the center of the screen, as it should be, and (1, 1, 0) when normalized to NDC is (1/ratio, 1, 0) which is the reason why it's at the top right.

So there is nothing going wrong, every thing is just working right.

You might want to read further on translations before doing any OGL, this link might be helpful:
http://www.opengl-tutorial.org/beginners-tutorials/tutorial-3-matrices/

Edited by IYP

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