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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 Large triangle/ slow fillrate?

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Hiya, I have an opengl program rendering 800 or so particles with alpha blending. The particles are actually small triangles, the texture is rendered within and clamped so that the corners are not shown (if that doesnt make sense don't worry). Basically i am rendering a ton of triangles and if the triangles are about .1 by .1 by .1 in size the framerate is wonderful, about 100-150. If they are enlarged (for smoke, fire etc) or if you are very very close to them so it fills a lot of the screen the framerate drops down to around 30 fps. I have tried turning off blending as well as textures and those both dont change anything performance wise (or at least nothing noticable). Also i'm in read-only mode for the z buffer I think its just the fill rate for the polygons, how can i fix this? Could it be i'm in some wierd rendering mode? Thanks

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its normal behaviour
use lower quality textures eg tex compression etc or dont draw the particles if they get above a certain size

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Again, even without any texturing at all, just white triangles, its slow.

Is opengl really that slow to fill triangles? is there a way to fix this?

as for sorting the polygons, it shouldnt really matter, if it never writes to the z buffer. Its just adding color to the screen

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Quote:
Original post by Pirosan
Again, even without any texturing at all, just white triangles, its slow.

Is opengl really that slow to fill triangles? is there a way to fix this?

No, your video card really is that slow. OpenGL doesn't have much to do with it.

As to actually being helpful, how about posting some code? I can't imagine that you'd be drawing a particle system with glBegin/End but how are we to know?

Typically, the root problem is overdraw. When you get close to the particle system and a single particle is near screen-size, rasterizing the screen 800 times (for each particle) is just too much for any vid card. Try using LOD for the system, draw less particles as the camera approaches for any system that uses unusually large particles.

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I do use glBegin and glEnd to render my triangles as particles.

My basic code is as follows... i set up the correct modes and calculate the theta (the direction this particular set of polygons is pointing. i do this once per bunch, i'm not expecting a certain set of particles to fly too far apart) in BillboardBegin:


cameraLocation[0] = camX;

cameraLocation[1] = camY;

cameraLocation[2] = camZ;



objectCenter[0] = objPosX;

objectCenter[1] = objPosY;

objectCenter[2] = objPosZ;

float[] distObject = new float[]{(camX - objPosX),(camY - objPosY), (camZ- objPosZ)};



GL11.glDisable(GL11.GL_LIGHTING);

GL11.glEnable(GL11.GL_BLEND);

GL11.glBlendFunc (GL11.GL_SRC_ALPHA, GL11.GL_ONE);



GL11.glDepthMask(false);





theta = (float) Math.atan(distObject[2] / distObject[0]);

System.out.println("the answer is:" + theta);



currCos = (float)(-theta * 180 / 3.14) + 90;

GL11.glTexParameterf(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL11.GL_CLAMP);

GL11.glTexParameterf(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL11.GL_CLAMP);



I render the polygons in DrawBillboard. I have a function which accesses an array of positions and sizes, it calls this method for each particle that is drawn:


GL11.glPushMatrix();

GL11.glTranslatef(p.x, p.y, p.z);

GL11.glRotatef(currCos,0f,1f,0f);


GL11.glBegin(GL11.GL_TRIANGLE_STRIP);


GL11.glTexCoord2f(-.5f,0);

GL11.glColor4f(p.color.r,p.color.g,p.color.b,p.color.a);

GL11.glVertex3f(-1.5f*p.size,-.5f*p.size,0);



GL11.glTexCoord2f(1.5f,0);

GL11.glVertex3f(1.5f*p.size,-.5f*p.size,0);

GL11.glTexCoord2f(0.5f,2);

GL11.glVertex3f(0*p.size,1.5f*p.size,0);


GL11.glEnd();
GL11.glPopMatrix();


You can sumise what i put for BillboardEnd, basically setting lighting to true, blending to false and so on.

Please be aware this is not C++, so the equasions and/or methods may look slightly different. this is Java, but it handles opengl the same way. I know i have done my calculations correctly, don't worry about that

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maybe this is stupid suggestion. but your debug print code could be really slow if it's put in the wrong place.

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not a stupid suggestion at all, thanks im sure that will speed something up :)

but it still slows down, is there a way to better optimize, or perhalps set in a more hardware rendering mode?

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You simply can't draw a ton of huge triangles, create an insane amount of overdraw and waste a ton of fillrate and just expect there to be magical switch to make it go fast. That's like asking for the magical words to make a cripple win olympic gold for 100m. If you can't find a way to prevent each pixel being set a few dozen times that's pretty much it. You can try using your own minimalistic fragment shader, but beyond that there simply is no glQuadrupleFillrate(GL_TRUE) function.

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That responce really didnt get me anywhere, i was being serious. I understand what you are saying, there is no fix it function or mode, i was just fishing around for advice. I don't know if opengl is taking full advantage of my graphics card or not.

In direct X there is a way to set rendering to software or hardware, is there one in opengl?

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The only way I know of would be either deinstalling the graphic card drivers (or installing those that came with Windows) or deliberately using a pixel format that isn't supported.

There was also something you can try. Use shaders or programs and let the fragment shader/program do nothing but output a constant color. That will pretty much tell you your upper limit.

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