Qt opengl assimp使用骨骼动画代码
时间: 2023-10-14 12:05:38 浏览: 155
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:
```c++
#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:
```c++
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:
```c++
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:
```c++
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:
```c++
// 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:
```glsl
#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:
```glsl
#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!
阅读全文