Qt opengl assimp使用骨骼动画代码

以下是使用Qt、OpenGL和Assimp库实现骨骼动画的代码示例：

1. 加载模型

Assimp::Importer importer;
const aiScene* scene = importer.ReadFile("path/to/model", aiProcess_Triangulate | aiProcess_FlipUVs | aiProcess_CalcTangentSpace | aiProcess_GenSmoothNormals | aiProcess_JoinIdenticalVertices | aiProcess_ImproveCacheLocality | aiProcess_LimitBoneWeights | aiProcess_RemoveRedundantMaterials);

if (!scene || !scene->HasMeshes()) {
    qDebug() << "Failed to load model";
    return;
}

std::vector<Mesh> meshes;
meshes.reserve(scene->mNumMeshes);

for (unsigned int i = 0; i < scene->mNumMeshes; i++) {
    aiMesh* mesh = scene->mMeshes[i];
    meshes.push_back(Mesh(mesh));
}

std::vector<Bone> bones;
bones.reserve(scene->mNumMeshes);

for (unsigned int i = 0; i < scene->mNumMeshes; i++) {
    aiMesh* mesh = scene->mMeshes[i];
    bones.push_back(Bone(mesh, scene->mRootNode));
}

2. 渲染模型

void renderMesh(const Mesh& mesh, const std::vector<Bone>& bones, const QMatrix4x4& modelMatrix, GLuint shaderProgram) {
    glBindVertexArray(mesh.getVAO());
    for (int i = 0; i < mesh.getNumSubMeshes(); i++) {
        const SubMesh& subMesh = mesh.getSubMesh(i);
        glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "model"), 1, GL_FALSE, modelMatrix.data());
        glUniformMatrix4fv(glGetUniformLocation(shaderProgram, "normalMatrix"), 1, GL_FALSE, modelMatrix.normalMatrix().data());
        glUniform1i(glGetUniformLocation(shaderProgram, "hasBones"), subMesh.getNumBones() > 0);

        for (int j = 0; j < subMesh.getNumBones(); j++) {
            const Bone& bone = bones[subMesh.getBone(j)];
            glUniformMatrix4fv(glGetUniformLocation(shaderProgram, ("bones[" + std::to_string(j) + "]").c_str()), 1, GL_FALSE, bone.getFinalTransform().data());
        }

        glDrawElements(GL_TRIANGLES, subMesh.getNumIndices(), GL_UNSIGNED_INT, (void*)(subMesh.getBaseIndex() * sizeof(unsigned int)));
    }
    glBindVertexArray(0);
}

3. 更新骨骼动画

void updateBones(const Bone& bone, const QMatrix4x4& parentTransform, std::vector<Matrix4f>& boneMatrices) {
    QMatrix4x4 nodeTransform = bone.getTransform();

    QMatrix4x4 globalTransform = parentTransform * nodeTransform;

    if (boneMatrices.size() <= bone.getIndex()) {
        boneMatrices.resize(bone.getIndex() + 1);
    }
    boneMatrices[bone.getIndex()] = globalTransform * bone.getOffsetMatrix();

    for (const auto& child : bone.getChildren()) {
        updateBones(child, globalTransform, boneMatrices);
    }
}

std::vector<Matrix4f> boneMatrices;
boneMatrices.reserve(bones.size());

for (const auto& bone : bones) {
    updateBones(bone, QMatrix4x4(), boneMatrices);
}

4. 绑定骨骼动画相关的shader变量

#version 330 core

layout (location = 0) in vec3 position;
layout (location = 1) in vec3 normal;
layout (location = 2) in vec2 texCoord;
layout (location = 3) in ivec4 boneIDs;
layout (location = 4) in vec4 boneWeights;

uniform mat4 model;
uniform mat4 normalMatrix;
uniform bool hasBones;

const int MAX_BONES = 100;

uniform mat4 bones[MAX_BONES];

out vec3 fragPos;
out vec3 fragNormal;
out vec2 fragTexCoord;

void main() {
    vec4 pos = vec4(position, 1.0);
    vec4 norm = vec4(normal, 0.0);

    if (hasBones) {
        mat4 boneTransform = bones[boneIDs.x] * boneWeights.x;
        boneTransform += bones[boneIDs.y] * boneWeights.y;
        boneTransform += bones[boneIDs.z] * boneWeights.z;
        boneTransform += bones[boneIDs.w] * boneWeights.w;

        pos = boneTransform * pos;
        norm = boneTransform * norm;
    }

    gl_Position = model * pos;
    fragPos = gl_Position.xyz;
    fragNormal = normalize((normalMatrix * norm).xyz);
    fragTexCoord = texCoord;
}

注意，在上述代码示例中，假设已经实现了Mesh和Bone类。在Mesh类中，需要实现以下方法：getVAO()、getNumSubMeshes()、getSubMesh()。在Bone类中，需要实现以下方法：getTransform()、getIndex()、getOffsetMatrix()、getFinalTransform()、getChildren()。