qt中根据RGB设置3D模型的值

在Qt中，可以使用QColor类来表示RGB颜色，并将其应用于3D模型。以下是一个示例，演示如何使用QColor设置3D模型的颜色值：

// 创建一个QColor对象来表示红色（255, 0, 0）
QColor color(255, 0, 0);

// 获取3D模型的材质
QMaterial* material = my3DModel->material();

// 将QColor对象转换为Qt3D的QColorRGBA对象
QColorRGBA colorRGBA(color.redF(), color.greenF(), color.blueF(), color.alphaF());

// 设置材质的颜色属性
material->setProperty("ambient", colorRGBA);
material->setProperty("diffuse", colorRGBA);
material->setProperty("specular", colorRGBA);

在上面的示例中，我们创建了一个QColor对象来表示红色，并将其转换为Qt3D的QColorRGBA对象。然后，我们将此颜色值应用于3D模型的材质，通过设置ambient、diffuse和specular属性来改变材质的颜色。

相关问题

Qt opengl assimp使用骨骼动画代码

以下是使用Assimp库和Qt OpenGL实现骨骼动画的示例代码：

首先，我们需要一个包含骨骼动画的3D模型文件。在此示例中，我们将使用Assimp提供的示例模型文件（dragon.dae）。

在我们的Qt OpenGL应用程序中，我们需要使用Assimp库来加载模型文件。以下是加载模型文件的代码：

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

Assimp::Importer importer;
const aiScene* scene = importer.ReadFile("path/to/dragon.dae", aiProcess_Triangulate | aiProcess_FlipUVs | aiProcess_GenSmoothNormals | aiProcess_JoinIdenticalVertices);

在加载模型文件后，我们需要遍历场景中的每个网格并将其渲染到屏幕上。以下是渲染场景的代码：

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

    // 绑定顶点数据
    glBindVertexArray(vao);
    glBindBuffer(GL_ARRAY_BUFFER, vbo);
    glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex) * mesh->mNumVertices, vertices, GL_STATIC_DRAW);
    glEnableVertexAttribArray(0);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
    glEnableVertexAttribArray(1);
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, normal));
    glEnableVertexAttribArray(2);
    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, texCoords));

    // 绑定骨骼数据
    glBindBuffer(GL_ARRAY_BUFFER, vboBones);
    glBufferData(GL_ARRAY_BUFFER, sizeof(BoneData) * mesh->mNumVertices, boneData, GL_STATIC_DRAW);
    glEnableVertexAttribArray(3);
    glVertexAttribIPointer(3, 4, GL_INT, sizeof(BoneData), (void*)0);
    glEnableVertexAttribArray(4);
    glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, sizeof(BoneData), (void*)offsetof(BoneData, weights));

    // 渲染网格
    glDrawElements(GL_TRIANGLES, mesh->mNumFaces * 3, GL_UNSIGNED_INT, indices);
}

注意，我们还需要为每个顶点提供与骨骼动画相关的数据。为此，我们需要在顶点结构体中添加骨骼ID和权重，并在渲染网格时将这些数据绑定到顶点属性中。

以下是顶点结构体和骨骼数据结构体的示例代码：

struct Vertex {
    glm::vec3 position;
    glm::vec3 normal;
    glm::vec2 texCoords;
    int boneIDs[4];
    float boneWeights[4];
};

struct BoneData {
    int ids[4];
    float weights[4];
};

接下来，我们需要实现骨骼动画的更新逻辑。为此，我们需要计算每个骨骼的变换矩阵，并将其乘以每个顶点相对于该骨骼的初始位置。以下是计算骨骼变换矩阵的示例代码：

void calculateBoneTransform(aiNode* node, glm::mat4 parentTransform) {
    glm::mat4 nodeTransform = convertToGLM(node->mTransformation);
    glm::mat4 globalTransform = parentTransform * nodeTransform;

    if (boneMap.find(node->mName.data) != boneMap.end()) {
        BoneData boneData;
        int boneIndex = boneMap[node->mName.data];
        aiMatrix4x4 boneMatrix = scene->mAnimations[0]->mChannels[boneIndex]->mNodeAnimations[frameIndex]->mTransformation;
        boneData.offsetMatrix = convertToGLM(boneMatrix);
        boneTransforms[boneIndex] = globalTransform * boneData.offsetMatrix;
    }

    for (unsigned int i = 0; i < node->mNumChildren; i++) {
        calculateBoneTransform(node->mChildren[i], globalTransform);
    }
}

在每个渲染帧中，我们需要更新当前帧的索引，计算每个骨骼的变换矩阵，并将其传递给着色器程序。以下是更新骨骼动画的示例代码：

// 更新当前帧
float animationTime = fmod(glfwGetTime(), scene->mAnimations[0]->mDuration);
frameIndex = animationTime * ticksPerSecond;

// 计算骨骼变换矩阵
calculateBoneTransform(scene->mRootNode, glm::mat4(1.0f));

// 将骨骼变换矩阵传递给着色器程序
for (unsigned int i = 0; i < MAX_BONES; i++) {
    glUniformMatrix4fv(glGetUniformLocation(shaderProgram, ("bones[" + std::to_string(i) + "]").c_str()), 1, GL_FALSE, glm::value_ptr(boneTransforms[i]));
}

最后，我们需要在着色器程序中实现顶点着色器中的骨骼动画逻辑。以下是顶点着色器中的骨骼动画代码：

#version 330 core

layout (location = 0) in vec3 aPos;
layout (location = 1) in vec3 aNormal;
layout (location = 2) in vec2 aTexCoords;
layout (location = 3) in ivec4 aBoneIDs;
layout (location = 4) in vec4 aBoneWeights;

uniform mat4 projection;
uniform mat4 view;
uniform mat4 model;
uniform mat4 bones[MAX_BONES];

out vec3 FragPos;
out vec3 Normal;
out vec2 TexCoords;

void main() {
    mat4 boneTransform = bones[aBoneIDs[0]] * aBoneWeights[0] + 
                         bones[aBoneIDs[1]] * aBoneWeights[1] + 
                         bones[aBoneIDs[2]] * aBoneWeights[2] + 
                         bones[aBoneIDs[3]] * aBoneWeights[3];
    vec4 transformedPos = boneTransform * vec4(aPos, 1.0);
    vec4 finalPos = model * transformedPos;

    gl_Position = projection * view * finalPos;
    FragPos = vec3(finalPos);
    Normal = mat3(transpose(inverse(model * boneTransform))) * aNormal;
    TexCoords = aTexCoords;
}

在顶点着色器中，我们首先计算每个顶点相对于骨骼的变换矩阵。然后，我们将该矩阵乘以顶点的初始位置，并将结果传递给片段着色器。

在片段着色器中，我们可以像通常一样处理颜色和光照。以下是片段着色器的示例代码：

#version 330 core

in vec3 FragPos;
in vec3 Normal;
in vec2 TexCoords;

uniform sampler2D textureSampler;

out vec4 FragColor;

void main() {
    vec3 objectColor = vec3(1.0, 0.5, 0.31);
    vec3 lightColor = vec3(1.0, 1.0, 1.0);
    vec3 lightPos = vec3(-2.0, 4.0, -1.0);

    vec3 ambient = 0.2 * lightColor;
    vec3 norm = normalize(Normal);
    vec3 lightDir = normalize(lightPos - FragPos);
    float diff = max(dot(norm, lightDir), 0.0);
    vec3 diffuse = diff * lightColor;
    vec3 viewDir = normalize(-FragPos);
    vec3 reflectDir = reflect(-lightDir, norm);
    float spec = pow(max(dot(viewDir, reflectDir), 0.0), 32.0);
    vec3 specular = spec * lightColor;

    vec4 texColor = texture(textureSampler, TexCoords);
    FragColor = vec4((ambient + diffuse + specular) * objectColor * texColor.rgb, texColor.a);
}

这就是使用Assimp库和Qt OpenGL实现骨骼动画的示例代码。希望对你有所帮助！

qt opengl assimp 加载骨骼动画完整代码

下面是使用 Qt、OpenGL 和 Assimp 库加载骨骼动画的完整代码示例。在这个示例中，我们使用 Assimp 库加载一个包含骨骼动画的模型，并在 OpenGL 中渲染它。

#include <QOpenGLWidget>
#include <QOpenGLFunctions>
#include <QOpenGLShaderProgram>
#include <QMatrix4x4>
#include <assimp/Importer.hpp>
#include <assimp/scene.h>
#include <assimp/postprocess.h>

class GLWidget : public QOpenGLWidget, protected QOpenGLFunctions
{
public:
    GLWidget(QWidget *parent = nullptr) : QOpenGLWidget(parent) {}

protected:
    void initializeGL() override {
        initializeOpenGLFunctions();

        // 编译顶点着色器和片段着色器
        m_program.addShaderFromSourceFile(QOpenGLShader::Vertex, ":/shader.vert");
        m_program.addShaderFromSourceFile(QOpenGLShader::Fragment, ":/shader.frag");
        m_program.link();

        // 加载模型
        Assimp::Importer importer;
        const aiScene* scene = importer.ReadFile("model.dae", aiProcess_Triangulate | aiProcess_FlipUVs | aiProcess_GenSmoothNormals | aiProcess_JoinIdenticalVertices | aiProcess_CalcTangentSpace | aiProcess_LimitBoneWeights);
        if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) {
            qWarning() << "Failed to load model:" << importer.GetErrorString();
            return;
        }

        // 初始化骨骼动画
        m_boneMatrices.resize(scene->mNumMeshes);
        m_boneOffsets.resize(scene->mNumMeshes);
        m_boneMapping.resize(scene->mNumMeshes);
        for (unsigned int i = 0; i < scene->mNumMeshes; i++) {
            aiMesh* mesh = scene->mMeshes[i];

            // 计算骨骼权重
            QVector<QVector<QPair<int, float>>> boneWeights(mesh->mNumVertices);
            for (unsigned int j = 0; j < mesh->mNumBones; j++) {
                aiBone* bone = mesh->mBones[j];
                int boneIndex = m_boneMapping[i].value(QString::fromUtf8(bone->mName.C_Str()), -1);
                if (boneIndex == -1) {
                    boneIndex = m_boneOffsets[i].size();
                    m_boneOffsets[i].append(QMatrix4x4());
                    m_boneMapping[i].insert(QString::fromUtf8(bone->mName.C_Str()), boneIndex);
                }
                m_boneOffsets[i][boneIndex] = QMatrix4x4((float*)bone->mOffsetMatrix.Transpose().a1);
                for (unsigned int k = 0; k < bone->mNumWeights; k++) {
                    aiVertexWeight weight = bone->mWeights[k];
                    boneWeights[weight.mVertexId].append(qMakePair(boneIndex, weight.mWeight));
                }
            }

            // 计算每个顶点的骨骼矩阵
            QVector<QVector<QMatrix4x4>> boneMatrices(mesh->mNumVertices);
            for (int j = 0; j < mesh->mNumVertices; j++) {
                QVector<QPair<int, float>> weights = boneWeights[j];
                for (int k = 0; k < weights.size(); k++) {
                    int boneIndex = weights[k].first;
                    float weight = weights[k].second;
                    boneMatrices[j].append(weight * m_boneOffsets[i][boneIndex]);
                }
            }

            // 上传骨骼矩阵到 GPU
            int boneMatrixLocation = m_program.attributeLocation(QString("boneMatrix[%1]").arg(i));
            for (int j = 0; j < boneMatrices.size(); j++) {
                for (int k = 0; k < 4; k++) {
                    for (int l = 0; l < 4; l++) {
                        m_boneMatrices[i][j].data()[k * 4 + l] = boneMatrices[j][k][l];
                    }
                }
            }
            m_program.setAttributeArray(boneMatrixLocation, GL_FLOAT_MAT4, m_boneMatrices[i].constData(), 4);
            m_program.enableAttributeArray(boneMatrixLocation);
        }

        // 上传顶点数据到 GPU
        glGenVertexArrays(1, &m_vao);
        glBindVertexArray(m_vao);
        for (unsigned int i = 0; i < scene->mNumMeshes; i++) {
            aiMesh* mesh = scene->mMeshes[i];
            GLuint vbo;
            glGenBuffers(1, &vbo);
            glBindBuffer(GL_ARRAY_BUFFER, vbo);
            glBufferData(GL_ARRAY_BUFFER, sizeof(float) * (3 + 3 + 2 + 4 * 4) * mesh->mNumVertices, nullptr, GL_STATIC_DRAW);
            float* data = (float*)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
            for (unsigned int j = 0; j < mesh->mNumVertices; j++) {
                aiVector3D position = mesh->mVertices[j];
                aiVector3D normal = mesh->mNormals[j];
                aiVector3D texcoord = mesh->mTextureCoords[0][j];
                for (int k = 0; k < 3; k++) {
                    *data++ = position[k];
                }
                for (int k = 0; k < 3; k++) {
                    *data++ = normal[k];
                }
                for (int k = 0; k < 2; k++) {
                    *data++ = texcoord[k];
                }
                for (int k = 0; k < m_boneMatrices[i][j].size(); k++) {
                    for (int l = 0; l < 4; l++) {
                        for (int m = 0; m < 4; m++) {
                            *data++ = m_boneMatrices[i][j](l, m);
                        }
                    }
                }
            }
            glUnmapBuffer(GL_ARRAY_BUFFER);
            int positionLocation = m_program.attributeLocation("position");
            glVertexAttribPointer(positionLocation, 3, GL_FLOAT, GL_FALSE, sizeof(float) * (3 + 3 + 2 + 4 * 4), (void*)0);
            glEnableVertexAttribArray(positionLocation);
            int normalLocation = m_program.attributeLocation("normal");
            glVertexAttribPointer(normalLocation, 3, GL_FLOAT, GL_FALSE, sizeof(float) * (3 + 3 + 2 + 4 * 4), (void*)(sizeof(float) * 3));
            glEnableVertexAttribArray(normalLocation);
            int texcoordLocation = m_program.attributeLocation("texcoord");
            glVertexAttribPointer(texcoordLocation, 2, GL_FLOAT, GL_FALSE, sizeof(float) * (3 + 3 + 2 + 4 * 4), (void*)(sizeof(float) * 6));
            glEnableVertexAttribArray(texcoordLocation);
            int boneMatrixLocation = m_program.attributeLocation(QString("boneMatrix[%1]").arg(i));
            for (int j = 0; j < 4; j++) {
                glVertexAttribPointer(boneMatrixLocation + j, 4, GL_FLOAT, GL_FALSE, sizeof(float) * (3 + 3 + 2 + 4 * 4), (void*)(sizeof(float) * (8 + j * 4)));
                glEnableVertexAttribArray(boneMatrixLocation + j);
                glVertexAttribDivisor(boneMatrixLocation + j, 1);
            }
        }

        // 加载纹理
        QImage image("texture.png");
        glGenTextures(1, &m_texture);
        glBindTexture(GL_TEXTURE_2D, m_texture);
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image.width(), image.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, image.constBits());
        glGenerateMipmap(GL_TEXTURE_2D);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        glBindTexture(GL_TEXTURE_2D, 0);

        // 开启深度测试和面剔除
        glEnable(GL_DEPTH_TEST);
        glEnable(GL_CULL_FACE);
    }

    void paintGL() override {
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        // 计算相机矩阵和投影矩阵
        QMatrix4x4 cameraMatrix;
        cameraMatrix.translate(0, 0, -10);
        QMatrix4x4 projectionMatrix;
        projectionMatrix.perspective(45, (float)width() / height(), 0.1f, 100.0f);

        // 绘制模型
        m_program.bind();
        m_program.setUniformValue("cameraMatrix", cameraMatrix);
        m_program.setUniformValue("projectionMatrix", projectionMatrix);
        glBindTexture(GL_TEXTURE_2D, m_texture);
        glBindVertexArray(m_vao);
        for (unsigned int i = 0; i < m_boneMatrices.size(); i++) {
            m_program.setUniformValue(QString("boneMatrix[%1]").arg(i), m_boneMatrices[i]);
        }
        for (unsigned int i = 0; i < m_boneMatrices.size(); i++) {
            aiMesh* mesh = scene->mMeshes[i];
            glDrawArrays(GL_TRIANGLES, 0, mesh->mNumVertices);
        }
    }

private:
    QOpenGLShaderProgram m_program;
    GLuint m_vao;
    GLuint m_texture;
    QVector<QMatrix4x4> m_boneMatrices;
    QVector<QVector<QMatrix4x4>> m_boneOffsets;
    QVector<QHash<QString, int>> m_boneMapping;
};

注：这个代码示例中使用 `m_program` 对象表示 OpenGL 着色器程序，`m_vao` 表示 OpenGL 顶点数组对象，`m_texture` 表示 OpenGL 纹理对象，`m_boneMatrices` 表示骨骼矩阵，`m_boneOffsets` 表示骨骼偏移矩阵，`m_boneMapping` 表示骨骼名称到骨骼索引的映射。其中 `:/shader.vert` 和 `:/shader.frag` 是着色器程序的代码文件，`model.dae` 是包含骨骼动画的模型文件，`texture.png` 是纹理文件。