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    • 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; using System.Collections.Generic; using System.IO; namespace Tutorial_08.net.sourceskyboxer { public class WaveFrontLoader { private static List<Vector3> vertices; private static List<Vector2> textures; private static List<Vector3> normals; private static List<int> indices; private static float[] verticesArray; private static float[] normalsArray; private static float[] texturesArray; private static int[] indicesArray; private static string[] lines; public static RawModel LoadObjModel(string filename, Loader loader) { if (!File.Exists("Contents/" + filename + ".obj")) { throw new FileNotFoundException("Error: wavefront file doesn't exist path: " + filename + ".png"); } vertices = new List<Vector3>(); textures = new List<Vector2>(); normals = new List<Vector3>(); indices = new List<int>(); lines = File.ReadAllLines("Contents/" + filename + ".obj"); try { foreach (string line in lines) { if (line == "" || line.StartsWith("#")) continue; string[] token = line.Split(' '); switch(token[0]) { case ("o"): string o = token[1]; break; case "v": Vector3 vertex = new Vector3(float.Parse(token[1]), float.Parse(token[2]), float.Parse(token[3])); vertices.Add(vertex); break; case "vn": Vector3 normal = new Vector3(float.Parse(token[1]), float.Parse(token[2]), float.Parse(token[3])); normals.Add(normal); break; case "vt": Vector2 texture = new Vector2(float.Parse(token[1]), float.Parse(token[2])); textures.Add(texture); break; case "f": texturesArray = new float[vertices.Count * 2]; normalsArray = new float[vertices.Count * 3]; verticesArray = new float[vertices.Count * 3]; indicesArray = new int[indices.Count]; int vertexPointer = 0; foreach (Vector3 vex in vertices) { verticesArray[vertexPointer++] = vex.X; verticesArray[vertexPointer++] = vex.Y; verticesArray[vertexPointer++] = vex.Z; } for (int i = 0; i < indices.Count; i++) { indicesArray[i] = indices[i]; } break; } } } catch (FileNotFoundException f) { throw new FileNotFoundException($"OBJ file not found: {f.FileName}", f); } catch (ArgumentException ae) { throw new ArgumentException("OBJ file is damaged", ae); } return loader.loadToVAO(verticesArray, texturesArray, indicesArray); } } } 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();
    • 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!
    • By mike44
      Hi
      I draw in a OpenGL framebuffer. All is fine but it eats FPS (frames per second), hence I wonder if I could execute the framebuffer drawing only every 5-10th loop or so?
      Many thanks
       
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OpenGL Code for legacy openGL but still compatible with new openGL

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I am developing a tool that need to support as a wish the old legacy openGL, but I still would like to make the things easy to be used with new openGL (using minimal switches and code reuse) The thing I need to develop dont need special features, just show triangles, simple color materials, normals, maybe textures. It would be something that can be done with legacy openGL, but I would like to still be able to use to extended in future to use some more features from shaders.. Could you suggest some tutorials or way that I can achieve this goal?

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Well, you could use OpenGL 3.x core context (or maybe OpenGL ES 2.0) while programming to avoid using legacy calls, use shaders with a low #version to allow easier conversion to the legacy version, use VBO, avoid doing fancy modern stuff, and everytime you add a call to a gl function you would need to check if it also exists in the legacy version (most likely 2.0 or 2.1, maybe 1.5 with some extensions) and only use it if thats true. Probably, you will find missing calls you need and then have to find a way around that, like creating a single VAO only when using the modern version. You would also need to regularly test with the legacy version.

That is, if you want to do all the extraneous work.rolleyes.gif

Edited by wintertime

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Thanks. I am also looking for a way to structure the data (polygons) so it can be more easily used in the two versions. What format could be handled by the two verions?

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Thanks. I am also looking for a way to structure the data (polygons) so it can be more easily used in the two versions. What format could be handled by the two verions?

You might want to check the list of formats supported by glInterleavedArrays to see if any of those would suit you. Here is the manual page. If you want to go the structures of arrays route, I believe anything that GL1.1 gl[Vertex|Normal|Texcoord|Color]Pointer works with also works with shaders in the newer versions.

 

If you want a more specific answer, you may want to wait for someone more experienced to chime in.

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You need to be more specific. OpenGL is not a carefully designed API with clear distinctions between versions. It's a collection of extensions and modifications, occasionally rolled up into an amalgamation christened with a version number, and then implemented to (often wildly) varying degrees of correctness and completeness by the many various hardware vendors. OpenGL apps tended to be very crash-prone or misbehave in crazy ways unless applications stuck to very vendor-specific limited subsets or specific sequences of function calls. In games, this was often just, "figure out how Quake did it, because that's the only thing the hardware driver vendors actually ****ing tested." Very modern drivers are much much better, but if you only cared about modern systems you wouldn't be asking about legacy version support, I'd wager. smile.png


Do you need to target OpenGL 2.0? 1.4? 1.0? What "era" of hardware? Are any particular extensions allowed? What operating systems need to be supported? Whose drivers do you need to remain compatible with? Are you even referring to actual OpenGL or is this legacy OpenGL|ES you're asking about?

The answers to those questions (and more I'm probably not remembering) will heavily modify the answer to your original question.


Opinion: If you need to support legacy systems and you aren't targeting some UNIX then just use DirectX 8 or 9; you'll spend less time wrestling with Khronos' API or implementations and be able to spend more time making a better application.

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Thanks for the answers. I mean by "legacy" the glBegin style with no extensions. So, the very basic of triangles, vertex color, vertex normals, textures. light. Something that will look like a beginner did in end 90's happy.png

No openES but it will need to support *nixs (linux and macOS) and win.

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You can write the whole thing in a modern GL version, and then write your own old skool Begin/Vertex/End functions on top.

One big game engine that I used did that -- it was built for D3D9/GCM/GX, but provided a GL1.x style API for immediate mode rendering.

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You can write the whole thing in a modern GL version, and then write your own old skool Begin/Vertex/End functions on top.

 

Would you like to explain it better? What do you mean "on top" ? Will that mix the two somehow at same time? Thanks!

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Thanks for the answers. I mean by "legacy" the glBegin style with no extensions. So, the very basic of triangles, vertex color, vertex normals, textures. light. Something that will look like a beginner did in end 90's happy.png

No openES but it will need to support *nixs (linux and macOS) and win.

Now I feel like we may be missing a critical piece of information. Will it be you who would use the glBegin etc. style programming, or will it be whoever it was who wished for this support?

 

 

You can write the whole thing in a modern GL version, and then write your own old skool Begin/Vertex/End functions on top.

 

Would you like to explain it better? What do you mean "on top" ? Will that mix the two somehow at same time? Thanks!

 

Hodgman means that you would write your own Begin function that sets up some lists or arrays to collect vertexes etc., Vertex functions that add to those, and an End function that actually draws those primitives using modern OpenGL. So it would be your very own implementation of "legacy OpenGL" using modern OpenGL.

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Is the program actually required to run on machines with very old GPU and drivers that only support GL1.x, no shaders etc. or is it just that you want to supply a legacy OpenGL style API for users of the program?

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