Qt opengl assimp使用骨骼动画代码

以下是使用Qt、OpenGL和Assimp实现骨骼动画的示例代码：

首先，需要在项目中包含assimp库和Qt的OpenGL模块。可以使用以下命令将它们添加到.pro文件中：

LIBS += -lassimp
QT += opengl

然后，需要编写一个用于渲染模型的OpenGL窗口类。以下是一个简单的示例：

#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <assimp/Importer.hpp>
#include <assimp/scene.h>
#include <assimp/postprocess.h>

class OpenGLWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
public:
    OpenGLWidget(QWidget *parent = 0);
    ~OpenGLWidget();

protected:
    void initializeGL();
    void resizeGL(int w, int h);
    void paintGL();

private:
    Assimp::Importer m_importer;
    const aiScene *m_scene;
};

在初始化函数中，需要加载模型并设置OpenGL状态：

void OpenGLWidget::initializeGL()
{
    initializeOpenGLFunctions();

    // Load model
    m_scene = m_importer.ReadFile("model.dae", aiProcess_Triangulate | aiProcess_GenSmoothNormals | aiProcess_FlipUVs | aiProcess_LimitBoneWeights);

    // Set up OpenGL state
    glEnable(GL_DEPTH_TEST);
    glDepthFunc(GL_LESS);
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
}

在绘制函数中，需要遍历场景中的所有节点和网格，并计算每个节点的变换矩阵。以下是绘制函数的示例代码：

void OpenGLWidget::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    // Set up camera
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(45.0, (double)width() / (double)height(), 0.1, 100.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

    // Draw meshes
    for (unsigned int i = 0; i < m_scene->mNumMeshes; i++)
    {
        const aiMesh *mesh = m_scene->mMeshes[i];

        // Set up vertex positions and normals
        glEnableClientState(GL_VERTEX_ARRAY);
        glVertexPointer(3, GL_FLOAT, 0, mesh->mVertices);
        glEnableClientState(GL_NORMAL_ARRAY);
        glNormalPointer(GL_FLOAT, 0, mesh->mNormals);

        // Set up bone weights and indices
        if (mesh->HasBones())
        {
            glEnableVertexAttribArray(4);
            glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, sizeof(VertexBoneData), (const GLvoid*)offsetof(VertexBoneData, weights));
            glEnableVertexAttribArray(5);
            glVertexAttribPointer(5, 4, GL_FLOAT, GL_FALSE, sizeof(VertexBoneData), (const GLvoid*)offsetof(VertexBoneData, indices));

            // Calculate bone matrices
            std::vector<aiMatrix4x4> boneMatrices(mesh->mNumBones);
            for (unsigned int j = 0; j < mesh->mNumBones; j++)
            {
                const aiBone *bone = mesh->mBones[j];
                aiMatrix4x4 boneMatrix = bone->mOffsetMatrix;
                const aiNode *node = m_scene->mRootNode->FindNode(bone->mName);
                while (node && node != mesh->mBones[j]->mNode)
                {
                    boneMatrix = node->mTransformation * boneMatrix;
                    node = node->mParent;
                }
                boneMatrices[j] = boneMatrix;
            }

            // Set up bone matrices
            glUniformMatrix4fv(glGetUniformLocation(m_shaderProgram.programId(), "boneMatrices"), mesh->mNumBones, GL_FALSE, (const GLfloat*)&boneMatrices[0]);
        }

        // Draw triangles
        glDrawElements(GL_TRIANGLES, mesh->mNumFaces * 3, GL_UNSIGNED_INT, mesh->mFaces[0].mIndices);

        // Disable vertex and normal arrays
        glDisableClientState(GL_VERTEX_ARRAY);
        glDisableClientState(GL_NORMAL_ARRAY);

        // Disable bone weights and indices
        if (mesh->HasBones())
        {
            glDisableVertexAttribArray(4);
            glDisableVertexAttribArray(5);
        }
    }

    // Swap buffers
    swapBuffers();
}

在这个示例中，假设模型使用了骨骼动画。因此，需要设置每个网格的顶点数据结构，其中包含每个顶点的骨骼权重和索引。以下是这个数据结构的示例代码：

struct VertexBoneData
{
    float weights[4];
    unsigned int indices[4];
};

在顶点着色器中，需要将顶点位置和法线变换为相机空间，并使用骨骼权重和索引来计算每个顶点的最终位置。以下是顶点着色器的示例代码：

#version 330

uniform mat4 projectionMatrix;
uniform mat4 modelViewMatrix;
uniform mat4 boneMatrices[100];

in vec3 vertexPosition;
in vec3 vertexNormal;
in vec4 vertexWeights;
in ivec4 vertexIndices;

out vec3 normal;

void main()
{
    mat4 boneMatrix = boneMatrices[vertexIndices.x] * vertexWeights.x;
    boneMatrix += boneMatrices[vertexIndices.y] * vertexWeights.y;
    boneMatrix += boneMatrices[vertexIndices.z] * vertexWeights.z;
    boneMatrix += boneMatrices[vertexIndices.w] * vertexWeights.w;

    gl_Position = projectionMatrix * modelViewMatrix * boneMatrix * vec4(vertexPosition, 1.0);
    normal = normalize(mat3(modelViewMatrix * boneMatrix) * vertexNormal);
}

在片段着色器中，可以使用法线和光照计算每个像素的颜色。以下是片段着色器的示例代码：

#version 330

uniform vec3 lightPosition;

in vec3 normal;

out vec4 fragmentColor;

void main()
{
    vec3 ambientColor = vec3(0.2, 0.2, 0.2);
    vec3 diffuseColor = vec3(1.0, 1.0, 1.0);
    vec3 specularColor = vec3(1.0, 1.0, 1.0);
    float shininess = 50.0;

    vec3 lightDirection = normalize(lightPosition - gl_FragCoord.xyz);
    vec3 normalDirection = normalize(normal);
    vec3 reflectionDirection = reflect(-lightDirection, normalDirection);

    float diffuseFactor = max(dot(lightDirection, normalDirection), 0.0);
    vec3 diffuseComponent = diffuseColor * diffuseFactor;

    float specularFactor = pow(max(dot(reflectionDirection, normalize(-gl_FragCoord.xyz)), 0.0), shininess);
    vec3 specularComponent = specularColor * specularFactor;

    fragmentColor = vec4(ambientColor + diffuseComponent + specularComponent, 1.0);
}

最后，需要在Qt应用程序中创建OpenGL窗口并运行事件循环。以下是一个简单的示例：

#include <QApplication>
#include "OpenGLWidget.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    OpenGLWidget w;
    w.show();

    return a.exec();
}

这就是使用Qt、OpenGL和Assimp实现骨骼动画的基本步骤和代码示例。