我正在OpenGL 3.3中构建一个3D模型查看器，但我无法正确显示我的纹理 . 我很确定texcoords（来自我正在加载的对象）是正确的 .
这是我的代码：main.cpp
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "glm/glm.hpp"
#include "glm/gtc/matrix_transform.hpp"
#include "glm/gtc/type_ptr.hpp"
#include "InputState.h"
#include "Viewer.h"
#include "Shader.hpp"
#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"
#define TINYOBJLOADER_IMPLEMENTATION
#include "tiny_obj_loader.h"
std::string folder = "cube-tex/";
std::string objPath = folder + "cube-tex.obj";
std::vector<tinyobj::shape_t> shapes;
std::vector<tinyobj::material_t> materials;
std::vector<GLuint> texID;
std::string meshMode = "WIREFRAME";
std::string lightMode = "DIRECTIONAL";
double startTime = glfwGetTime();
float initScale = 1;
float zoom = 0;
float xRot, yRot;
int winX = 500;
int winY = 500;
std::vector<unsigned int> vaoHandle;
ObjectViewer *ObjCam;
Viewer *Camera;
glm::vec3 cameraPos(0.0f, 0.0f, -10.0f);
// Data structure storing mouse input info
InputState Input;
unsigned int programID;
unsigned int debugShader;
unsigned int lightTexShader;
//
// Callbacks
//
void key_callback(GLFWwindow* window,
int key, int scancode, int action, int mods)
{
if (action == GLFW_PRESS) {
switch(key)
{
case GLFW_KEY_S:
if (programID == lightTexShader) {
programID = debugShader;
meshMode = "WIREFRAME";
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
}
else {
programID = lightTexShader;
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
}
break;
case GLFW_KEY_ESCAPE: // escape key pressed
glfwSetWindowShouldClose(window, GL_TRUE);
break;
case GLFW_KEY_D:
if(programID == debugShader){
if(meshMode == "WIREFRAME") {
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
meshMode = "NORMAL";
}else if(meshMode == "NORMAL"){
meshMode = "MATERIAL";
}else{
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
meshMode = "WIREFRAME";
}
}
break;
case GLFW_KEY_L:
if(programID == lightTexShader){
if(lightMode == "DIRECTIONAL") {
lightMode = "HEADLIGHT";
}else if(lightMode == "HEADLIGHT"){
lightMode = "ROTATING";
}else{
lightMode = "DIRECTIONAL";
}
}
break;
default:
break;
}
}
}
// Set the projection matrix. Takes into account window aspect ratio, so called
// when the window is resized.
void setProjection(unsigned int id)
{
glm::mat4 projection;
projection = glm::perspective( (float)M_PI/3.0f, (float) winX / winY, 1.0f, 30.0f );
// Load it to the shader program
int projHandle = glGetUniformLocation(id, "projection");
if (projHandle == -1) {
std::cout << "Uniform: projection_matrix is not an active uniform label\n";
}
glUniformMatrix4fv( projHandle, 1, false, glm::value_ptr(projection) );
}
// Called when the window is resized.
void reshape_callback( GLFWwindow *window, int x, int y )
{
winX = x;
winY = y;
setProjection(programID);
glViewport( 0, 0, x, y );
}
void mouse_pos_callback(GLFWwindow* window, double x, double y)
{
// Use a global data structure to store mouse info
// We can then use it however we want
Input.update((float)x, (float)y);
}
void mouse_button_callback(GLFWwindow* window, int button, int action, int mods)
{
if (button == GLFW_MOUSE_BUTTON_RIGHT && action == GLFW_PRESS) {
Input.rMousePressed = true;
}
else if (button == GLFW_MOUSE_BUTTON_RIGHT && action == GLFW_RELEASE) {
Input.rMousePressed = false;
}
else if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_PRESS) {
Input.lMousePressed = true;
}
else if (button == GLFW_MOUSE_BUTTON_LEFT && action == GLFW_RELEASE) {
Input.lMousePressed = false;
}
}
int setupLight()
{
// light position uniform
int lightposHandle = glGetUniformLocation(programID, "light_pos");
if (lightposHandle == -1) {
fprintf(stderr, "Error: can't find matrix uniforms\n");
exit(1);
}
// Uniform lighting variables
int lightambientHandle = glGetUniformLocation(programID, "light_ambient");
int lightdiffuseHandle = glGetUniformLocation(programID, "light_diffuse");
int lightspecularHandle = glGetUniformLocation(programID, "light_specular");
if ( lightambientHandle == -1 ||
lightdiffuseHandle == -1 ||
lightspecularHandle == -1) {
fprintf(stderr, "Error: can't find light uniform variables\n");
return 1;
}
float lightPos[4]; // light position //= { 0.0f, 10.0f, 0.0f, 1.0f };
float lightambient[3]; // ambient light components
float lightdiffuse[3]; // diffuse light components
float lightspecular[3]; // specular light components
if(lightMode == "DIRECTIONAL"){
lightambient[0] = 0.0f;
lightambient[1] = 0.0f;
lightambient[2] = 0.0f;
lightdiffuse[0] = 0.5f;
lightdiffuse[1] = 0.5f;
lightdiffuse[2] = 1.0f;
lightspecular[0] = 1.0f;
lightspecular[1] = 1.0f;
lightspecular[2] = 1.0f;
lightPos[0] = -10.0f;
lightPos[1] = -10.0f;
lightPos[2] = -10.0f;
lightPos[3] = 0.0f;
}else if(lightMode == "HEADLIGHT"){
lightambient[0] = 0.0f;
lightambient[1] = 0.0f;
lightambient[2] = 0.0f;
lightdiffuse[0] = 1.0f;
lightdiffuse[1] = 1.0f;
lightdiffuse[2] = 1.0f;
lightspecular[0] = 1.0f;
lightspecular[1] = 1.0f;
lightspecular[2] = 1.0f;
glm::mat3 rotMat(Camera->getViewMtx());
glm::vec3 d((Camera->getViewMtx())[3]);
glm::vec3 tmp = -d * rotMat;
lightPos[0] = tmp[0];
lightPos[1] = tmp[1];
lightPos[2] = tmp[2];
lightPos[3] = 1.0f;
}else if(lightMode == "ROTATING"){
lightambient[0] = 0.0f;
lightambient[1] = 0.0f;
lightambient[2] = 0.0f;
lightdiffuse[0] = 1.0f;
lightdiffuse[1] = 1.0f;
lightdiffuse[2] = 0.2f;
lightspecular[0] = 1.0f;
lightspecular[1] = 1.0f;
lightspecular[2] = 0.2f;
double now = glfwGetTime();
lightPos[0] = 10 * cos((now - startTime));
lightPos[1] = 0.0f;
lightPos[2] = 10 * sin((now - startTime));
lightPos[3] = 1.0f;
}
glUniform4fv(lightposHandle, 1, lightPos);
glUniform3fv(lightambientHandle, 1, lightambient);
glUniform3fv(lightdiffuseHandle, 1, lightdiffuse);
glUniform3fv(lightspecularHandle, 1, lightspecular);
return 0; // return success
}
void computeInitScale(){
float minX = 0;
float minY = 0;
float maxX = 0;
float maxY = 0;
for(int i = 0; i < shapes.size(); i++){
for(int j = 0; j < shapes[i].mesh.positions.size()/3; j++){
//max and min X
if(shapes[i].mesh.positions[3*j+0] > maxX){
maxX = shapes[i].mesh.positions[3*j+0];
}else if(shapes[i].mesh.positions[3*j+0] < minX){
minX = shapes[i].mesh.positions[3*j+0];
}
//max and min Y
if(shapes[i].mesh.positions[3*j+1] > maxY){
maxY = shapes[i].mesh.positions[3*j+1];
}else if(shapes[i].mesh.positions[3*j+1] < minY){
minY = shapes[i].mesh.positions[3*j+1];
}
}
}
initScale = 2 / std::max(maxX - minX, maxY - minY);
}
void loadRGBTexture(const char *path)
{
int x, y, n;
// Load from file. Force RGB image pixel format
unsigned char *data = stbi_load(path, &x, &y, &n, 3);
// Copy to GPU as data for the currently active texture.
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, x, y, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
stbi_image_free(data);
glGenerateMipmap(GL_TEXTURE_2D);
}
void setMaterials(int i){
// material
int mtlambientHandle = glGetUniformLocation(programID, "mtl_ambient");
int mtldiffuseHandle = glGetUniformLocation(programID, "mtl_diffuse");
int mtlspecularHandle = glGetUniformLocation(programID, "mtl_specular");
if (mtlambientHandle == -1 || mtldiffuseHandle == -1 || mtlspecularHandle == -1) {
fprintf(stderr, "Error: can't find material uniform variables\n");
}
float mtlambient[3];
mtlambient[0] = materials[shapes[i].mesh.material_ids[0]].ambient[0];
mtlambient[1] = materials[shapes[i].mesh.material_ids[0]].ambient[1];
mtlambient[2] = materials[shapes[i].mesh.material_ids[0]].ambient[2];
float mtldiffuse[3];
mtldiffuse[0] = materials[shapes[i].mesh.material_ids[0]].diffuse[0];
mtldiffuse[1] = materials[shapes[i].mesh.material_ids[0]].diffuse[1];
mtldiffuse[2] = materials[shapes[i].mesh.material_ids[0]].diffuse[2];
float mtlspecular[3];
mtlspecular[0] = materials[shapes[i].mesh.material_ids[0]].specular[0];
mtlspecular[1] = materials[shapes[i].mesh.material_ids[0]].specular[1];
mtlspecular[2] = materials[shapes[i].mesh.material_ids[0]].specular[2];
glUniform3fv(mtlambientHandle, 1, mtlambient);
glUniform3fv(mtldiffuseHandle, 1, mtldiffuse);
glUniform3fv(mtlspecularHandle, 1, mtlspecular);
}
void loadObj(){
std::string err;
bool ret = tinyobj::LoadObj(shapes, materials, err, objPath.c_str(), folder.c_str());
if (!err.empty()) {
std::cerr << err << std::endl;
}
if (!ret) {
exit(1);
}
std::cout << "# of shapes : " << shapes.size() << std::endl;
std::cout << "# of materials : " << materials.size() << std::endl;
for (size_t i = 0; i < shapes.size(); i++) {
printf("shape[%ld].name = %s\n", i, shapes[i].name.c_str());
printf("Size of shape[%ld].indices: %ld\n", i, shapes[i].mesh.indices.size());
printf("Size of shape[%ld].material_ids: %ld\n", i, shapes[i].mesh.material_ids.size());
assert((shapes[i].mesh.indices.size() % 3) == 0);
for (size_t f = 0; f < shapes[i].mesh.indices.size() / 3; f++) {
printf(" idx[%ld] = %d, %d, %d. mat_id = %d\n", f, shapes[i].mesh.indices[3*f+0], shapes[i].mesh.indices[3*f+1], shapes[i].mesh.indices[3*f+2], shapes[i].mesh.material_ids[f]);
}
printf("shape[%ld].vertices: %ld\n", i, shapes[i].mesh.positions.size());
assert((shapes[i].mesh.positions.size() % 3) == 0);
for (size_t v = 0; v < shapes[i].mesh.positions.size() / 3; v++) {
printf(" v[%ld] = (%f, %f, %f)\n", v,
shapes[i].mesh.positions[3*v+0],
shapes[i].mesh.positions[3*v+1],
shapes[i].mesh.positions[3*v+2]);
}
}
for (size_t i = 0; i < materials.size(); i++) {
printf("material[%ld].name = %s\n", i, materials[i].name.c_str());
printf(" material.Ka = (%f, %f ,%f)\n", materials[i].ambient[0], materials[i].ambient[1], materials[i].ambient[2]);
printf(" material.Kd = (%f, %f ,%f)\n", materials[i].diffuse[0], materials[i].diffuse[1], materials[i].diffuse[2]);
printf(" material.Ks = (%f, %f ,%f)\n", materials[i].specular[0], materials[i].specular[1], materials[i].specular[2]);
printf(" material.Tr = (%f, %f ,%f)\n", materials[i].transmittance[0], materials[i].transmittance[1], materials[i].transmittance[2]);
printf(" material.Ke = (%f, %f ,%f)\n", materials[i].emission[0], materials[i].emission[1], materials[i].emission[2]);
printf(" material.Ns = %f\n", materials[i].shininess);
printf(" material.Ni = %f\n", materials[i].ior);
printf(" material.dissolve = %f\n", materials[i].dissolve);
printf(" material.illum = %d\n", materials[i].illum);
printf(" material.map_Ka = %s\n", materials[i].ambient_texname.c_str());
printf(" material.map_Kd = %s\n", materials[i].diffuse_texname.c_str());
printf(" material.map_Ks = %s\n", materials[i].specular_texname.c_str());
printf(" material.map_Ns = %s\n", materials[i].specular_highlight_texname.c_str());
std::map<std::string, std::string>::const_iterator it(materials[i].unknown_parameter.begin());
std::map<std::string, std::string>::const_iterator itEnd(materials[i].unknown_parameter.end());
for (; it != itEnd; it++) {
printf(" material.%s = %s\n", it->first.c_str(), it->second.c_str());
}
printf("\n");
}
computeInitScale();
}
void createVAO()
{
for(int i = 0; i < shapes.size(); i++){
vaoHandle.push_back(0);
glGenVertexArrays(1, &vaoHandle[i]);
glBindVertexArray(vaoHandle[i]);
unsigned int buffer[5];
glGenBuffers(4, buffer);
// Set vertex attribute
glBindBuffer(GL_ARRAY_BUFFER, buffer[0]);
glBufferData(GL_ARRAY_BUFFER,
sizeof(float) * shapes[i].mesh.positions.size(), &shapes[i].mesh.positions[0], GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);
// Set vertex attribute
glBindBuffer(GL_ARRAY_BUFFER, buffer[1]);
glBufferData(GL_ARRAY_BUFFER,
sizeof(float) * shapes[i].mesh.normals.size(), &shapes[i].mesh.normals[0], GL_STATIC_DRAW);
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);
// create material array
float diffuse[shapes[i].mesh.indices.size() * 3];
for(int j = 0; j<shapes[i].mesh.indices.size(); j++){
int index = j*3;
diffuse[index] = materials[shapes[i].mesh.material_ids[j/3]].diffuse[0];
diffuse[index + 1] = materials[shapes[i].mesh.material_ids[j/3]].diffuse[1];
diffuse[index + 2] = materials[shapes[i].mesh.material_ids[j/3]].diffuse[2];
}
// Set vertex attribute
glBindBuffer(GL_ARRAY_BUFFER, buffer[2]);
glBufferData(GL_ARRAY_BUFFER,
shapes[i].mesh.indices.size() * 3 * sizeof(float) , &diffuse[0], GL_STATIC_DRAW);
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 0, 0);
// Set element attributes. Notice the change to using GL_ELEMENT_ARRAY_BUFFER
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffer[3]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
sizeof(float) * shapes[i].mesh.indices.size(), &shapes[i].mesh.indices[0], GL_STATIC_DRAW);
// load textures
texID.push_back(0);
glGenTextures(1, &texID[i] );
glActiveTexture(GL_TEXTURE0);
glBindTexture( GL_TEXTURE_2D, texID[i] );
loadRGBTexture((folder + (std::string) materials[shapes[i].mesh.material_ids[0]].diffuse_texname).c_str());
// load texture coordinates
int texLoc = glGetAttribLocation(programID, "a_tex_coord");
glBindBuffer(GL_ARRAY_BUFFER, buffer[4]);
glBufferData(GL_ARRAY_BUFFER,
shapes[i].mesh.texcoords.size() * sizeof(float) , &shapes[i].mesh.texcoords[0], GL_STATIC_DRAW);
glEnableVertexAttribArray(texLoc);
glVertexAttribPointer(texLoc, 3, GL_FLOAT, GL_FALSE, 0, 0);
// Un-bind
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
}
}
void render()
{
glUseProgram(programID);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
setProjection(programID);
Camera->update(Input);
glm::mat4 viewMatrix;
viewMatrix = Camera->getViewMtx();
// Load viex to the shader program
int viewHandle = glGetUniformLocation(programID, "view");
if (viewHandle == -1) {
std::cout << "Uniform: view is not an active uniform label\n";
}
glUniformMatrix4fv( viewHandle, 1, false, glm::value_ptr(viewMatrix) );
// Load the model matrix
int modelUniformHandle = glGetUniformLocation(programID, "model");
if (modelUniformHandle == -1)
exit(1);
// calculate zoom
if(Input.rMousePressed){
zoom += Input.yDiff/10;
if (zoom < 0) zoom = 0;
if (zoom > 1.5) zoom = 1.5;
}
glm::mat4 model;
model = glm::scale( model, glm::vec3(initScale + zoom, initScale + zoom, initScale + zoom));
glUniformMatrix4fv( modelUniformHandle, 1, false, glm::value_ptr(model) );
if (programID == debugShader){
// set colour mode
int modeHandle = glGetUniformLocation(programID, "mode");
if (modeHandle == -1) {
std::cout << "Uniform: mode is not an active uniform label\n";
}
if(meshMode == "MATERIAL"){
glUniform1i( modeHandle, 1);
}else{
glUniform1i( modeHandle, 0);
}
}else{
setupLight();
}
// Load meshes
for(int i = 0; i < shapes.size(); i++){
glBindVertexArray(vaoHandle[i]);
glDrawElements(GL_TRIANGLES, shapes[i].mesh.indices.size(), GL_UNSIGNED_INT, 0);
if (programID == lightTexShader){
setMaterials(i);
int texHandle = glGetUniformLocation(programID, "texMap");
if (texHandle == -1) {
fprintf(stderr, "Could not find uniform variables\n");
exit(1);
}
glBindTexture(GL_TEXTURE_2D, texID[i]);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR_MIPMAP_NEAREST);
}
glBindVertexArray(0);
}
}
/**
* Error callback for GLFW. Simply prints error message to stderr.
*/
static void error_callback(int error, const char* description)
{
fputs(description, stderr);
}
int main (int argc, char **argv)
{
GLFWwindow* window;
glfwSetErrorCallback(error_callback);
if (!glfwInit()) {
exit(1);
}
// Specify that we want OpenGL 3.3
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
// Create the window and OpenGL context
window = glfwCreateWindow(winX, winY, "Modelling and viewing", NULL, NULL);
if (!window)
{
glfwTerminate();
exit(1);
}
glfwMakeContextCurrent(window);
glfwSwapInterval(1);
// Initialize GLEW
glewExperimental = true; // Needed for core profile
if (glewInit() != GLEW_OK) {
fprintf(stderr, "Failed to initialize GLEW\n");
exit(1);
}
// load shaders
debugShader = LoadShaders("mview.vert", "mview.frag");
lightTexShader = LoadShaders("light-texture.vert", "light-texture.frag");
if (debugShader == 0 || lightTexShader == 0) {
exit(1);
}
programID = debugShader;
// Set OpenGL state we need for this application.
glClearColor(0.5F, 0.5F, 0.5F, 0.0F);
glEnable(GL_DEPTH_TEST);
glUseProgram(programID);
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
// Set up the scene and the cameras
//setProjection(debugShader);
//setProjection(lightTexShader);
loadObj();
createVAO();
ObjCam = new ObjectViewer( cameraPos );
Camera = ObjCam;
// Define callback functions and start main loop
glfwSetKeyCallback(window, key_callback);
glfwSetCursorPosCallback(window, mouse_pos_callback);
glfwSetMouseButtonCallback(window, mouse_button_callback);
glfwSetFramebufferSizeCallback(window, reshape_callback);
while (!glfwWindowShouldClose(window))
{
render();
glfwSwapBuffers(window);
glfwPollEvents();
}
glfwDestroyWindow(window);
glfwTerminate();
exit(0);
return 0;
}
顶点着色器
#version 330
uniform mat4 projection_matrix;
uniform mat4 modelview_matrix;
//uniform mat3 normal_matrix;
layout (location = 0) in vec3 a_vertex;
layout (location = 1) in vec3 a_normal;
layout (location = 2) in vec3 a_diffuse;
in vec2 a_tex_coord;
uniform mat4 projection;
uniform mat4 view;
uniform mat4 model;
//uniform int mode;
uniform vec3 mtl_diffuse;
out vec4 vertex; // vertex position in eye space
out vec3 normal; // the eye space normal
out vec2 st;
void main(void)
{
vertex = view * model * vec4(a_vertex, 1.0);
//normal = normalize(normal_matrix * a_normal);
normal = a_normal;
st = a_tex_coord;
gl_Position = projection * view * model * vec4(a_vertex, 1.0);
}
片段着色器
#version 330
in vec4 vertex;
in vec3 normal;
in vec2 st;
out vec4 fragColour;
uniform sampler2D texMap;
uniform vec4 light_pos;
uniform vec3 light_ambient; // Light ambient RGBA values
uniform vec3 light_diffuse; // Light diffuse RGBA values
uniform vec3 light_specular; // Light specular RGBA values
uniform vec3 mtl_ambient; // Ambient surface colour
uniform vec3 mtl_diffuse; // Diffuse surface colour
uniform vec3 mtl_specular; // Specular surface colour
const float shininess = 32;
vec3 phongPointLight(in vec4 position, in vec3 norm)
{
vec3 s = normalize(vec3(light_pos - position));
if(light_pos.w == 0.0){
s = -normalize(light_pos.xyz);
}
vec3 v = normalize(-position.xyz);
vec3 r = reflect( -s, norm );
vec3 ambient = light_ambient * mtl_ambient;
// The diffuse component
float sDotN = max( dot(s,norm), 0.0 );
vec3 diffuse = light_diffuse * mtl_diffuse * sDotN;
// The specular component BLINN
vec3 spec = vec3(0.0);
vec3 halfwayDir = normalize(s + v);
if ( sDotN > 0.0 )
spec = light_specular * mtl_specular * pow(max(dot(normalize(normal), halfwayDir), 0.0), 32.0);
return ambient + diffuse + spec;
}
void main(void)
{
fragColour = vec4(phongPointLight(vertex, normalize(normal)), 1.0) * texture(texMap, st);
}
这是结果 . 正如您所看到的，纹理没有正确定位在汽车上 .