我正在使用OpenGL v.3.3。以及来自learningopengl.com的完整源代码示例。我可以从教程(nanosuit.obj)中运行纹理化模型,但是当我尝试加载另一个没有纹理但具有.mtl文件的.obj模型时,它显示为深色。我认为问题可能出在我用来加载模型的着色器中,但我不知道如何重做着色器的代码来解决我的问题。
这是我用来渲染模型的主要功能:
void COpenGLControl::oglInitialize(void)
{
static PIXELFORMATDESCRIPTOR pfd =
{
sizeof(PIXELFORMATDESCRIPTOR),
1,
PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA,
32, // bit depth
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
16, // z-buffer depth
0, 0, 0, 0, 0, 0, 0,
};
// Get device context only once.
hdc = GetDC()->m_hDC;
// Pixel format.
m_nPixelFormat = ChoosePixelFormat(hdc, &pfd);
SetPixelFormat(hdc, m_nPixelFormat, &pfd);
// Create the OpenGL Rendering Context.
hrc = wglCreateContext(hdc);
wglMakeCurrent(hdc, hrc);
if (!gladLoadGL())
{
AfxMessageBox(L"Error loading glad");
return;
}
// configure global opengl state
// -----------------------------
glEnable(GL_DEPTH_TEST);
// build and compile shaders
ourShader = Shader("resource/shaders/modelLoading.vs", "resource/shaders/modelLoading.frag");
// load models
ourModel = Model("resource/models/car12/LaFerrari.obj");
// Send draw request
OnDraw(NULL);
}
void COpenGLControl::oglDrawScene(void)
{
// render
// ------
glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// don't forget to enable shader before setting uniforms
ourShader.use();
// view/projection transformations
glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)900 / (float)900, 0.1f, 100.0f);
glm::mat4 view = camera.GetViewMatrix();
ourShader.setMat4("projection", projection);
ourShader.setMat4("view", view);
// render the loaded model
glm::mat4 model = glm::mat4(1.0f);
model = glm::translate(model, glm::vec3(0.0f, 0.0f, 0.0f));
model = glm::scale(model, glm::vec3(0.010f, 0.010f, 0.010f));
model = glm::rotate(model, glm::radians(-30.0f), glm::vec3(0.0f, 1.0f, 0.0f));
model = glm::rotate(model, glm::radians(20.0f), glm::vec3(1.0f, 0.0f, 0.0f));
ourShader.setMat4("model", model);
ourModel.Draw(ourShader);
}
mesh.h
#ifndef MESH_H
#define MESH_H
#include <glad/glad.h> // holds all OpenGL type declarations
#include <glm.hpp>
#include <gtc/matrix_transform.hpp>
#include "shader_m.h"
#include <string>
#include <fstream>
#include <sstream>
#include <iostream>
#include <vector>
using namespace std;
struct Vertex {
// position
glm::vec3 Position;
// normal
glm::vec3 Normal;
// texCoords
glm::vec2 TexCoords;
// tangent
glm::vec3 Tangent;
// bitangent
glm::vec3 Bitangent;
};
struct Material {
//Material color lighting
glm::vec4 Ka;
//Diffuse reflection
glm::vec4 Kd;
//Mirror reflection
glm::vec4 Ks;
};
struct Texture {
unsigned int id;
string type;
string path;
};
class Mesh {
public:
/* Mesh Data */
vector<Vertex> vertices;
vector<unsigned int> indices;
vector<Texture> textures;
Material mats;
unsigned int VAO;
unsigned int uniformBlockIndex;
/* Functions */
// constructor
Mesh(vector<Vertex> vertices, vector<unsigned int> indices, vector<Texture> textures, Material mat)
{
this->vertices = vertices;
this->indices = indices;
this->textures = textures;
this->mats = mat;
// now that we have all the required data, set the vertex buffers and its attribute pointers.
setupMesh();
}
// render the mesh
void Draw(Shader shader)
{
// bind appropriate textures
unsigned int diffuseNr = 1;
unsigned int specularNr = 1;
unsigned int normalNr = 1;
unsigned int heightNr = 1;
for (unsigned int i = 0; i < textures.size(); i++)
{
glActiveTexture(GL_TEXTURE0 + i); // active proper texture unit before binding
// retrieve texture number (the N in diffuse_textureN)
string number;
string name = textures[i].type;
if (name == "texture_diffuse")
number = std::to_string(diffuseNr++);
else if (name == "texture_specular")
number = std::to_string(specularNr++); // transfer unsigned int to stream
else if (name == "texture_normal")
number = std::to_string(normalNr++); // transfer unsigned int to stream
else if (name == "texture_height")
number = std::to_string(heightNr++); // transfer unsigned int to stream
// now set the sampler to the correct texture unit
glUniform1i(glGetUniformLocation(shader.ID, (name + number).c_str()), i);
// and finally bind the texture
glBindTexture(GL_TEXTURE_2D, textures[i].id);
}
// draw mesh
glBindVertexArray(VAO);
glBindBufferRange(GL_UNIFORM_BUFFER, 0, uniformBlockIndex, 0, sizeof(Material));
glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
// always good practice to set everything back to defaults once configured.
glActiveTexture(GL_TEXTURE0);
}
private:
/* Render data */
unsigned int VBO, EBO;
/* Functions */
// initializes all the buffer objects/arrays
void setupMesh()
{
// create buffers/arrays
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
glGenBuffers(1, &EBO);
glGenBuffers(1, &uniformBlockIndex);
glBindVertexArray(VAO);
// load data into vertex buffers
glBindBuffer(GL_ARRAY_BUFFER, VBO);
// A great thing about structs is that their memory layout is sequential for all its items.
// The effect is that we can simply pass a pointer to the struct and it translates perfectly to a glm::vec3/2 array which
// again translates to 3/2 floats which translates to a byte array.
glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex) + sizeof(mats), &vertices[0], GL_STATIC_DRAW);
glBindBuffer(GL_UNIFORM_BUFFER, uniformBlockIndex);
glBufferData(GL_UNIFORM_BUFFER, sizeof(mats), (void*)(&mats), GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), &indices[0], GL_STATIC_DRAW);
// set the vertex attribute pointers
// vertex Positions
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);
// vertex normals
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Normal));
// vertex texture coords
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, TexCoords));
// vertex tangent
glEnableVertexAttribArray(3);
glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Tangent));
// vertex bitangent
glEnableVertexAttribArray(4);
glVertexAttribPointer(4, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Bitangent));
//glBindVertexArray(0);
}
};
#endif
model.cpp
#include "pch.h"
#include "model.h"
Model::Model(void)
{
}
Model::Model(string const& path, bool gamma)
{
loadModel(path);
}
void Model::Draw(Shader shader)
{
for (unsigned int i = 0; i < meshes.size(); i++)
meshes[i].Draw(shader);
}
void Model::loadModel(string const& path)
{
// read file via ASSIMP
Assimp::Importer importer;
const aiScene* scene = importer.ReadFile(path, aiProcess_Triangulate | aiProcess_FlipUVs | aiProcess_CalcTangentSpace);
// check for errors
if (!scene || scene->mFlags & AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) // if is Not Zero
{
cout << "ERROR::ASSIMP:: " << importer.GetErrorString() << endl;
return;
}
// retrieve the directory path of the filepath
directory = path.substr(0, path.find_last_of('/'));
// process ASSIMP's root node recursively
processNode(scene->mRootNode, scene);
}
void Model::processNode(aiNode* node, const aiScene* scene)
{
// process each mesh located at the current node
for (unsigned int i = 0; i < node->mNumMeshes; i++)
{
// the node object only contains indices to index the actual objects in the scene.
// the scene contains all the data, node is just to keep stuff organized (like relations between nodes).
aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
meshes.push_back(processMesh(mesh, scene));
}
// after we've processed all of the meshes (if any) we then recursively process each of the children nodes
for (unsigned int i = 0; i < node->mNumChildren; i++)
{
processNode(node->mChildren[i], scene);
}
}
Mesh Model::processMesh(aiMesh* mesh, const aiScene* scene)
{
// data to fill
vector<Vertex> vertices;
vector<unsigned int> indices;
vector<Texture> textures;
// Walk through each of the mesh's vertices
for (unsigned int i = 0; i < mesh->mNumVertices; i++)
{
Vertex vertex;
glm::vec3 vector; // we declare a placeholder vector since assimp uses its own vector class that doesn't directly convert to glm's vec3 class so we transfer the data to this placeholder glm::vec3 first.
// positions
if (!mesh->mVertices == NULL)
{
vector.x = mesh->mVertices[i].x;
vector.y = mesh->mVertices[i].y;
vector.z = mesh->mVertices[i].z;
vertex.Position = vector;
}
else
{
vertex.Position = glm::vec3(0.0f, 0.0f, 0.0f);
//AfxMessageBox(L"Positions is NULL");
}
// normals
if (!mesh->mNormals == NULL)
{
vector.x = mesh->mNormals[i].x;
vector.y = mesh->mNormals[i].y;
vector.z = mesh->mNormals[i].z;
vertex.Normal = vector;
}
else
{
vertex.Normal = glm::vec3(0.0f, 0.0f, 0.0f);
//AfxMessageBox(L"Normals is NULL");
}
// texture coordinates
if (mesh->mTextureCoords[0]) // does the mesh contain texture coordinates?
{
glm::vec2 vec;
// a vertex can contain up to 8 different texture coordinates. We thus make the assumption that we won't
// use models where a vertex can have multiple texture coordinates so we always take the first set (0).
vec.x = mesh->mTextureCoords[0][i].x;
vec.y = mesh->mTextureCoords[0][i].y;
vertex.TexCoords = vec;
}
else
{
vertex.TexCoords = glm::vec2(0.0f, 0.0f);
//AfxMessageBox(L"TextCoords is NULL");
}
// tangent
if (!mesh->mTangents == NULL)
{
vector.x = mesh->mTangents[i].x;
vector.y = mesh->mTangents[i].y;
vector.z = mesh->mTangents[i].z;
vertex.Tangent = vector;
}
else
{
vertex.Tangent = glm::vec3(0.0f, 0.0f, 0.0f);
//AfxMessageBox(L"TextCoords is NULL");
}
// bitangent
if (!mesh->mBitangents == NULL)
{
vector.x = mesh->mBitangents[i].x;
vector.y = mesh->mBitangents[i].y;
vector.z = mesh->mBitangents[i].z;
vertex.Bitangent = vector;
}
else
{
vertex.Bitangent = glm::vec3(0.0f, 0.0f, 0.0f);
//AfxMessageBox(L"Bitangent is NULL");
}
vertices.push_back(vertex);
}
// now wak through each of the mesh's faces (a face is a mesh its triangle) and retrieve the corresponding vertex indices.
for (unsigned int i = 0; i < mesh->mNumFaces; i++)
{
aiFace face = mesh->mFaces[i];
// retrieve all indices of the face and store them in the indices vector
for (unsigned int j = 0; j < face.mNumIndices; j++)
indices.push_back(face.mIndices[j]);
}
// process materials
aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex];
aiColor3D color;
Material mat;
// Read mtl file vertex data
material->Get(AI_MATKEY_COLOR_AMBIENT, color);
mat.Ka = glm::vec4(color.r, color.g, color.b, 1.0);
material->Get(AI_MATKEY_COLOR_DIFFUSE, color);
mat.Kd = glm::vec4(color.r, color.g, color.b, 1.0);
material->Get(AI_MATKEY_COLOR_SPECULAR, color);
mat.Ks = glm::vec4(color.r, color.g, color.b, 1.0);
// we assume a convention for sampler names in the shaders. Each diffuse texture should be named
// as 'texture_diffuseN' where N is a sequential number ranging from 1 to MAX_SAMPLER_NUMBER.
// Same applies to other texture as the following list summarizes:
// diffuse: texture_diffuseN
// specular: texture_specularN
// normal: texture_normalN
// 1. diffuse maps
vector<Texture> diffuseMaps = loadMaterialTextures(material, aiTextureType_DIFFUSE, "texture_diffuse");
textures.insert(textures.end(), diffuseMaps.begin(), diffuseMaps.end());
// 2. specular maps
vector<Texture> specularMaps = loadMaterialTextures(material, aiTextureType_SPECULAR, "texture_specular");
textures.insert(textures.end(), specularMaps.begin(), specularMaps.end());
// 3. normal maps
std::vector<Texture> normalMaps = loadMaterialTextures(material, aiTextureType_HEIGHT, "texture_normal");
textures.insert(textures.end(), normalMaps.begin(), normalMaps.end());
// 4. height maps
std::vector<Texture> heightMaps = loadMaterialTextures(material, aiTextureType_AMBIENT, "texture_height");
textures.insert(textures.end(), heightMaps.begin(), heightMaps.end());
// return a mesh object created from the extracted mesh data
return Mesh(vertices, indices, textures, mat);
}
vector<Texture> Model::loadMaterialTextures(aiMaterial* mat, aiTextureType type, string typeName)
{
vector<Texture> textures;
for (unsigned int i = 0; i < mat->GetTextureCount(type); i++)
{
aiString str;
mat->GetTexture(type, i, &str);
// check if texture was loaded before and if so, continue to next iteration: skip loading a new texture
bool skip = false;
for (unsigned int j = 0; j < textures_loaded.size(); j++)
{
if (std::strcmp(textures_loaded[j].path.data(), str.C_Str()) == 0)
{
textures.push_back(textures_loaded[j]);
skip = true; // a texture with the same filepath has already been loaded, continue to next one. (optimization)
break;
}
}
if (!skip)
{ // if texture hasn't been loaded already, load it
Texture texture;
texture.id = TextureFromFile(str.C_Str(), this->directory, false);
texture.type = typeName;
texture.path = str.C_Str();
textures.push_back(texture);
textures_loaded.push_back(texture); // store it as texture loaded for entire model, to ensure we won't unnecesery load duplicate textures.
}
}
return textures;
}
unsigned int Model::TextureFromFile(const char* path, const string& directory, bool gamma)
{
//string filename = string(path);
//filename = directory + '/' + filename;
string filename = string(path);
if (directory.find(R"(/)") != std::string::npos)
{
filename = directory + R"(/)" + filename;
}
else if (directory.find(R"(\\)") != std::string::npos)
{
filename = directory + R"(\\)" + filename;
}
stbi_set_flip_vertically_on_load(false);
unsigned int textureID;
glGenTextures(1, &textureID);
int width, height, nrComponents;
unsigned char* data = stbi_load(filename.c_str(), &width, &height, &nrComponents, 0);
if (data)
{
GLenum format;
if (nrComponents == 1)
format = GL_RED;
else if (nrComponents == 3)
format = GL_RGB;
else if (nrComponents == 4)
format = GL_RGBA;
glBindTexture(GL_TEXTURE_2D, textureID);
glTexImage2D(GL_TEXTURE_2D, 0, format, width, height, 0, format, GL_UNSIGNED_BYTE, data);
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);
stbi_image_free(data);
}
else
{
std::cout << "Texture failed to load at path: " << path << std::endl;
stbi_image_free(data);
}
return textureID;
}
也附有图片(深色图片是我程序的结果,彩色图片是AbViewer免费obj查看器的结果)。请帮助我找到解决方案,我在做什么错?
这里是着色器
modelloading.vs
#version 330 core
layout ( location = 0 ) in vec3 position;
layout ( location = 1 ) in vec3 normal;
layout ( location = 2 ) in vec2 texCoords;
out vec2 TexCoords;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main( )
{
gl_Position = projection * view * model * vec4( position, 1.0f );
TexCoords = texCoords;
}
modelLoading.frag
#version 330 core
in vec2 TexCoords;
out vec4 color;
uniform sampler2D texture_diffuse;
void main( )
{
color = vec4( texture( texture_diffuse, TexCoords ));
}
[据推测,GLSL程序希望绑定纹理以进行渲染。 在这种情况下,可以使用两种方法-将GLSL代码修改为 (可选)忽略纹理获取,或创建并绑定虚拟白色 缺少纹理贴图的纹理]
我是OpenGL的新手(学习的第二天),请给我更详细的解释该怎么做