• Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • 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!
    • 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 !
  • Advertisement
  • Advertisement
Sign in to follow this  

OpenGL GLSL Skinning problem

This topic is 1919 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

Hello community,

 
Ok, first of all, I'm using OpenGL 3, 3ds max, and Delphi to create a skeletal animation demo. I'm using the IGame interface to export meshes from 3ds max to XML - I use the sample included in the SDK.
 
Now, I'm going to describe as precisely as I can what I do.
 
Passing bone weights to the shader
I'll skip parsing geometry, because it works okay. Now, if a mesh is skinned (using the Physique modifier), the resulting XML contains information about bone influences for each vertex, like so:
    <Skin VertexID="2" Type="Rigid">
       <Bone BoneID="22" Weight="1,000000"></Bone>
    </Skin>
    ...
    <Skin VertexID="14" Type="Blended">
       <Bone BoneID="22" Weight="0,986472"></Bone>
       <Bone BoneID="14" Weight="0,013015"></Bone>
       <Bone BoneID="23" Weight="0,000513"></Bone>
    </Skin>
    ...
    <Skin VertexID="31" Type="Blended">
       <Bone BoneID="22" Weight="0,948354"></Bone>
       <Bone BoneID="23" Weight="0,030462"></Bone>
       <Bone BoneID="23" Weight="0,011265"></Bone>
       <Bone BoneID="14" Weight="0,009909"></Bone>
       <Bone BoneID="23" Weight="0,000011"></Bone>
    </Skin>

My shader assumes that there should be always 4 bones, which influence a single vertex, and as you can see, sometimes there is sulprus/insufficient number of them, so I decided to:

  1. Sum up weights of the same bone - take a look at vertex 31 - there are five entries, but after summing them up, we're left with three.
  2. Pad the remaining number of weights with zero.
Right now, I have a list of bone IDs/vertex weight pairs, which I pass to the shader like so:
    const
       MAX_BONES_PER_VERTEX = 4;
    
    type
       TVertexWeight = record
          BoneID: Integer;
          Weight: Single; // standard float
       end;
    ...
    var
      L: TList<TVertexWeight>;
    ...
    glGenBuffers(1, @FBonesVBO);
    glBindBuffer(GL_ARRAY_BUFFER, FBonesVBO);
    glBufferData(GL_ARRAY_BUFFER, L.ListSize, L.ListPointer, GL_STATIC_DRAW);
    
    glEnableVertexAttribArray(FBoneIDsAttr);
    glVertexAttribIPointer(FBoneIDsAttr, MAX_BONES_PER_VERTEX, GL_INT,
       SizeOf(TVertexWeight), PInteger(0));
    
    glEnableVertexAttribArray(FWeightsAttr);
    glVertexAttribPointer(FWeightsAttr, MAX_BONES_PER_VERTEX, GL_FLOAT,
       False, SizeOf(TVertexWeight), PInteger(4));

I think this part is working fine, because when I hardcode an identity matrix in the shader, the model is rendered in its bind pose.

 
Computing bone matrices
For now, I just want to display the model in a pose which it would be in, let's say, frame 49:
3oZhZ.png
 
Here's the code I use:
procedure CalculateBones(const SequenceName: String; const FrameID: Integer;
const ABone: TAnimatedMeshBone; const ParentTransform: TBrainMatrix);
var
   Samples: TBrainList<TAnimatedMeshAnimationSample>;
   BoneSample: TAnimatedMeshAnimationSample;
   I: Integer;
   BoneTransform, GlobalTransform: TBrainMatrix;
   Children: TBonesList;
begin
   Samples := TBrainList<TAnimatedMeshAnimationSample>.Create();
   Children := TBonesList.Create();
   try
      FAnims[SequenceName].SamplesByFrame(FrameID, Samples);
      BoneSample := nil;
      for I := 0 to Samples.Count -1 do
         if (Samples[I].Bone.ID = ABone.ID) then
         begin
            BoneSample := Samples[I];
            break;
         end;


      BoneTransform := ABone.OffsetMatrix;
      if (BoneSample <> nil) then
         BoneTransform := BoneSample.Matrix;
      
      GlobalTransform := Mat4Multiply(ParentTransform, BoneTransform);


      BoneMatrices.Add(GlobalTransform);


      FBones.BonesByParentID(ABone.ID, Children);
      for I := 0 to Children.Count -1 do
         CalculateBones(SequenceName, FrameID, Children[I], GlobalTransform);
   finally
      Samples.Free();
      Children.Free();
   end;
end;
...
BoneMatrices := TBrainList<TBrainMatrix>.Create();
try
   // A bone's offset matrix is the bind pose.
   CalculateBones('zhuxian2', 49, FBones.RootBone, FBones.RootBone.OffsetMatrix);
   glUniformMatrix4fv(FShader.GetUniformLocation('boneMatrices'),
      BoneMatrices.Count, False, BoneMatrices.ListPointer);
finally
   BoneMatrices.Free();
end;
A bone's OffsetMatrix is basically the bind pose (regarding to what the exporter says, it's in object space) of the bone. Now, a TAnimatedMeshAnimationSample contains position and rotation (in quaternion) of a bone in the given frame. The loop at the top of CalculateBones() basically checks if in the given frame (in this case, 49th) there's transformation data for the given bone.
 
After launching the code above, all I get is this: (please ignore the lack of textures for now)
HBJjC.png
 
But when I change the initial parent transform from FBones.RootBone.OffsetMatrix to Mat4Identity() (basically use an identity matrix), the model is displayed in its bind pose:
5hcab.png
 
Vertex shader code

 

#version 150


#define MAX_BONES_PER_VERTEX 4
#define MAX_BONES 32


uniform mat4 proj;
uniform mat4 modelview;
uniform mat4 boneMatrices[MAX_BONES];


in vec3 vertex;
in vec3 normal;
in vec2 texCoord;
in ivec4 boneIDs;
in vec4 boneWeights;


out vec4 fragmentColor;


float phong_weightCalc(in vec3 light_pos, in vec3 frag_normal) {
   return max(0.0, dot(frag_normal, light_pos));
}


mat4 getBoneMatrix(int boneIndex) {
   mat4 retMat = mat4(1.0);
   if (boneIDs[boneIndex] != 0) {
      retMat = boneMatrices[boneIDs[boneIndex]];
   }
   return retMat;   
}


float getWeight(int boneIndex) {
   float res = 1.0;
   if (boneIDs[boneIndex] != 0) {
      res = boneWeights[boneIndex];
   }
   return res;
}


void main() {
   vec3 EC_Light_location = vec3(0.0, 1.0, 1.0);
   
   float diffuse_weight = phong_weightCalc(
      normalize(EC_Light_location),
      normalize(normal)
   );
   
   fragmentColor = clamp(
      (
         (vec4(0.2, 0.2, 0.2, 1.0))
         + (vec4(0.8, 0.8, 0.8, 1.0) * diffuse_weight)
      ), 
      0.0, 1.0);
         
   float totalWeight = 0.0;
   vec4 PosL = vec4(0.0, 0.0, 0.0, 1.0);
   for (int i = 0; i < MAX_BONES_PER_VERTEX; i++) {
      float w = getWeight(i);
      PosL += w * (vec4(vertex, 1.0) * getBoneMatrix(i));
      totalWeight += w;
   }
   PosL /= totalWeight;
   PosL.w = 1.0;


   gl_Position = proj * modelview * PosL;
}

 

The question is, can someone point out what is wrong with the code?

 
Thank you very much.
 
PS. If you need any more information, please let me know.

 

Share this post


Link to post
Share on other sites
Advertisement

I'm afraid I haven't read through all the code, but one quick idea; when you create a 'Pad the remaining number of weights with zero' are you also setting the bone ID to something valid? I once had an issue on a console where a weight of zero combined with an invalid bone matrix to produce a non-zero garbage value on the GPU.

Share this post


Link to post
Share on other sites

[quote name='C0lumbo' timestamp='1358784975' post='5023946']
when you create a 'Pad the remaining number of weights with zero' are you also setting the bone ID to something valid?
[/quote]

Yes, I set it to zero, then in the shader I verify whether the bone ID is set to 0, like so:

 

 

mat4 getBoneMatrix(int boneIndex) {
   mat4 retMat = mat4(1.0);
   if (boneIDs[boneIndex] != 0) {
      retMat = boneMatrices[boneIDs[boneIndex]];
   }
   return retMat;   
}

float getWeight(int boneIndex) {
   float res = 1.0;
   if (boneIDs[boneIndex] != 0) {
      res = boneWeights[boneIndex];
   }
   return res;
}

Share this post


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

  • Advertisement