我正在使用openGL c ++创建一个天空盒，现在我按照天空盒上的一些教程，我已经设置了所有图像，但我的天空盒根本没有被绘制！ （我只看到黑色的opengl背景）
所以这是我的代码，可能是什么问题？我正在看它几个小时，找不到东西，我是openGL的新手，所以如果你发现任何不好的代码请告诉我！谢谢！
#include <iostream>
#include <stdlib.h>
#ifdef __APPLE__
#include <OpenGL/OpenGL.h>
#include <GLUT/glut.h>
#else
#include <GL/glut.h>
#endif
#include "imageloader.h"
using namespace std;
//angle of rotation
GLfloat xpos = 0, ypos = 0, zpos = 0, xrot = 0, yrot = 0, angle=0.0;
GLuint _textureId; //The OpenGL id of the texture
GLuint _skybox[5];
float lastx, lasty;
bool leftMouseButton = false;
float PI = 3.141592654f;
//Makes the image into a texture, and returns the id of the texture
GLuint __loadTexture(Image* image) {
GLuint textureId;
glGenTextures(1, &textureId);
glBindTexture(GL_TEXTURE_2D, textureId);
glTexImage2D(GL_TEXTURE_2D,
0,
GL_RGB,
image->width, image->height,
0,
GL_RGB,
GL_UNSIGNED_BYTE,
image->pixels);
return textureId;
}
GLuint __loadMipmappedTexture(Image *image) {
GLuint textureId;
glGenTextures(1, &textureId);
glBindTexture(GL_TEXTURE_2D, textureId);
gluBuild2DMipmaps(GL_TEXTURE_2D,
GL_RGB,
image->width, image->height,
GL_RGB,
GL_UNSIGNED_BYTE,
image->pixels);
return textureId;
}
void initRendering() {
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_NORMALIZE);
glEnable(GL_COLOR_MATERIAL);
glEnable(GL_CULL_FACE);
glShadeModel (GL_SMOOTH); //set the shader to smooth shader
Image* image = loadBMP("artesis.bmp");
_textureId = __loadMipmappedTexture(image);
image = loadBMP("skybox/deep_ft.bmp");
_skybox[0] = __loadMipmappedTexture(image);
image = loadBMP("skybox/deep_lf.bmp");
_skybox[1] = __loadMipmappedTexture(image);
image = loadBMP("skybox/deep_bk.bmp");
_skybox[2] = __loadMipmappedTexture(image);
image = loadBMP("skybox/deep_rt.bmp");
_skybox[3] = __loadMipmappedTexture(image);
image = loadBMP("skybox/deep_up.bmp");
_skybox[4] = __loadMipmappedTexture(image);
image = loadBMP("skybox/deep_dn.bmp");
_skybox[5] = __loadMipmappedTexture(image);
delete image;
}
void handleResize(int w, int h) {
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (double)w / (double)h, 1.0, 100.0);
glViewport (0, 0, w, h);
glMatrixMode(GL_MODELVIEW);
glutPostRedisplay();
}
void mouseMovement(int x, int y) {
if (leftMouseButton == true)
{
GLfloat diffx = (x-lastx)/20; //check the difference between the current x and the last x position
GLfloat diffy = (y-lasty)/20; //check the difference between the current y and the last y position
lastx = x; //set lastx to the current x position
lasty = y; //set lasty to the current y position
xrot += (float) diffy; //set the xrot to xrot with the addition of the difference in the y position
yrot += (float) diffx; //set the xrot to yrot with the addition of the difference in the x position
}
else if( leftMouseButton == false)
{
GLfloat diffx = x-lastx; //check the difference between the current x and the last x position
GLfloat diffy = y-lasty; //check the difference between the current y and the last y position
lastx = x; //set lastx to the current x position
lasty = y; //set lasty to the current y position
}
}
void mouseButtons(int button, int state, int x, int y) {
if ((state == GLUT_DOWN) && (button == GLUT_LEFT_BUTTON))
{
leftMouseButton = true;
}
else if ((state == GLUT_DOWN) && (button == GLUT_RIGHT_BUTTON))
{
leftMouseButton = false;
}
}
void drawGrid(float size, float step)
{
// disable lighting
glDisable(GL_LIGHTING);
glBegin(GL_LINES);
glColor3f(0.3f, 0.3f, 0.3f);
for(float i=step; i <= size; i+= step)
{
glVertex3f(-size, 0, i); // lines parallel to X-axis
glVertex3f( size, 0, i);
glVertex3f(-size, 0, -i); // lines parallel to X-axis
glVertex3f( size, 0, -i);
glVertex3f( i, 0, -size); // lines parallel to Z-axis
glVertex3f( i, 0, size);
glVertex3f(-i, 0, -size); // lines parallel to Z-axis
glVertex3f(-i, 0, size);
}
// x-axis
glColor3f(0.5f, 0, 0);
glVertex3f(-size, 0, 0);
glVertex3f( size, 0, 0);
// z-axis
glColor3f(0,0,0.5f);
glVertex3f(0, 0, -size);
glVertex3f(0, 0, size);
glEnd();
// enable lighting back
glEnable(GL_LIGHTING);
}
void keyboard (unsigned char key, int x, int y) {
float xrotrad, yrotrad;
switch(key) {
case 'a':
xrot += 1;
if(xrot > 360) xrot -= 360;
break;
case 'w':
xrot -= 1;
if(xrot < -360) xrot += 360;
break;
case 'z':
yrotrad = (yrot / 180 * PI);
xrotrad = (xrot / 180 * PI);
xpos += float(sin(yrotrad));
zpos -= float(cos(yrotrad));
ypos -= float(sin(xrotrad));
break;
case 's':
yrotrad = (yrot / 180 * PI);
xrotrad = (xrot / 180 * PI);
xpos -= float(sin(yrotrad));
zpos += float(cos(yrotrad));
ypos += float(sin(xrotrad));
break;
case 'd':
yrot += 1;
if (yrot >360) yrot -= 360;
break;
case 'q':
yrot -= 1;
if (yrot < -360)yrot += 360;
break;
case 27:
exit(0);
break;
}
}
void camera (void) {
glRotatef(xrot,1.0,0.0,0.0); //rotate our camera on teh x-axis (left and right)
glRotatef(yrot,0.0,1.0,0.0); //rotate our camera on the y-axis (up and down)
glTranslated(-xpos,-ypos,-zpos); //translate the screen to the position of our camera
}
void drawScene() {
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
GLfloat lightKa[] = {.0f, .0f, .0f, 1.0f}; // ambient light
GLfloat lightKd[] = {.9f, .9f, .9f, 1.0f}; // diffuse light
GLfloat lightKs[] = {1, 1, 1, 1}; // specular light
glLightfv(GL_LIGHT0, GL_AMBIENT, lightKa);
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightKd);
glLightfv(GL_LIGHT0, GL_SPECULAR, lightKs);
// position the light
float lightPos[4] = {0, 10, 10, 0};
glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
camera();
//call the skybox
// Store the current matrix
glPushMatrix();
// Reset and transform the matrix.
glLoadIdentity();
/* EDIT: I really dont know how to set gluLookAt, I guess it should be the camera positions??? */
gluLookAt(
0.0,0.0,0.0,
0.1, 0.0, 0.1,
0.0,1.0,0.0);
// Enable/Disable features
glPushAttrib(GL_ENABLE_BIT);
glEnable(GL_TEXTURE_2D);
glDisable(GL_DEPTH_TEST);
glDepthMask(false);
glDisable(GL_LIGHTING);
glDisable(GL_BLEND);
// Just in case we set all vertices to white.
glColor4f(1,1,1,1);
// Render the front quad
glBindTexture(GL_TEXTURE_2D, _skybox[0]);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex3f( 0.5f, -0.5f, -0.5f );
glTexCoord2f(1, 0); glVertex3f( -0.5f, -0.5f, -0.5f );
glTexCoord2f(1, 1); glVertex3f( -0.5f, 0.5f, -0.5f );
glTexCoord2f(0, 1); glVertex3f( 0.5f, 0.5f, -0.5f );
glEnd();
// Render the left quad
glBindTexture(GL_TEXTURE_2D, _skybox[1]);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex3f( 0.5f, -0.5f, 0.5f );
glTexCoord2f(1, 0); glVertex3f( 0.5f, -0.5f, -0.5f );
glTexCoord2f(1, 1); glVertex3f( 0.5f, 0.5f, -0.5f );
glTexCoord2f(0, 1); glVertex3f( 0.5f, 0.5f, 0.5f );
glEnd();
// Render the back quad
glBindTexture(GL_TEXTURE_2D, _skybox[2]);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex3f( -0.5f, -0.5f, 0.5f );
glTexCoord2f(1, 0); glVertex3f( 0.5f, -0.5f, 0.5f );
glTexCoord2f(1, 1); glVertex3f( 0.5f, 0.5f, 0.5f );
glTexCoord2f(0, 1); glVertex3f( -0.5f, 0.5f, 0.5f );
glEnd();
// Render the right quad
glBindTexture(GL_TEXTURE_2D, _skybox[3]);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex3f( -0.5f, -0.5f, -0.5f );
glTexCoord2f(1, 0); glVertex3f( -0.5f, -0.5f, 0.5f );
glTexCoord2f(1, 1); glVertex3f( -0.5f, 0.5f, 0.5f );
glTexCoord2f(0, 1); glVertex3f( -0.5f, 0.5f, -0.5f );
glEnd();
// Render the top quad
glBindTexture(GL_TEXTURE_2D, _skybox[4]);
glBegin(GL_QUADS);
glTexCoord2f(0, 1); glVertex3f( -0.5f, 0.5f, -0.5f );
glTexCoord2f(0, 0); glVertex3f( -0.5f, 0.5f, 0.5f );
glTexCoord2f(1, 0); glVertex3f( 0.5f, 0.5f, 0.5f );
glTexCoord2f(1, 1); glVertex3f( 0.5f, 0.5f, -0.5f );
glEnd();
// Render the bottom quad
glBindTexture(GL_TEXTURE_2D, _skybox[5]);
glBegin(GL_QUADS);
glTexCoord2f(0, 0); glVertex3f( -0.5f, -0.5f, -0.5f );
glTexCoord2f(0, 1); glVertex3f( -0.5f, -0.5f, 0.5f );
glTexCoord2f(1, 1); glVertex3f( 0.5f, -0.5f, 0.5f );
glTexCoord2f(1, 0); glVertex3f( 0.5f, -0.5f, -0.5f );
glEnd();
// Restore enable bits and matrix
glPopAttrib();
glPopMatrix();
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_BLEND);
glDepthMask(true);
glClear(GL_DEPTH_BUFFER_BIT);
drawGrid(20, 1);
glutSwapBuffers(); //swap the buffers
}
void update(int value) {
angle++; //increase the angle
glutPostRedisplay(); //Tell GLUT that the display has changed
//Tell GLUT to call update again in 25 milliseconds
glutTimerFunc(25, update, 0);
}
int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(800, 800);
glutCreateWindow("Block Position");
initRendering();
glutDisplayFunc(drawScene);
glutKeyboardFunc(keyboard);
glutIdleFunc(drawScene);
glutReshapeFunc(handleResize);
glutPassiveMotionFunc(mouseMovement);
glutTimerFunc(25, update, 0); //Add a timer
glutMouseFunc(mouseButtons);
glutMainLoop();
return 0;
}
答案 0 :(得分：2)
如果没有任何内容出现，可能是因为天空框不在场景中，因为它在屏幕上culled（或未呈现）。
在代码中，您为100.0指定了zFar：
gluPerspective(45.0, (double)w / (double)h, 1.0, 100.0);
更改zFar值以适应天空盒的大小（比如500.0），它应该出现。
答案 1 :(得分：1)
你应该从最小的渲染开始，比如没有闪电，没有面部剔除，只有白色的三角形。因此，如果您看到白色，那么至少您的相机位置可能正常。然后你可以启用剔除，如果全部消失，那么这就是你的问题 - 法线方向错误。然后，如果一切正常，则启用照明，然后进行纹理处理 - 并始终检查更改内容。
所以不要太难看，但要消除复杂性 - 甚至检查一下简单的trianlge是否会出现在预期的位置。