glNormalPointer似乎不正確

Question

我編寫了一個類來導入.obj models.But法線似乎不正確。 因此，我試着在我的代碼中查找錯誤很多天，但我沒有找到任何錯誤。 然後我改變了「glDrawElement()」如下代碼。

for(int i=0;i<trianglesNumber;i++) 
{ 
glBegin(GL_TRIANGLES); 
glNormal3f();glVertex3f(); 
glNormal3f();glVertex3f(); 
glNormal3f();glVertex3f(); 
glEnd(); 
} 

然後法線是正確的。

我想知道如何解決這個問題。但是，當導入更大的模型時，第二種方法的FPS太低。如果你能幫我解決這個問題，我將非常感激。

下面是兩種方法的代碼和結果。

1：

void init() 
{ 
    glEnableClientState(GL_VERTEX_ARRAY); 
    glEnableClientState(GL_TEXTURE_COORD_ARRAY); 
    glEnableClientState(GL_NORMAL_ARRAY); 
    glTexCoordPointer(3,GL_DOUBLE,0,textures); 
    glNormalPointer(GL_DOUBLE,0,normals); 
    glVertexPointer(3,GL_DOUBLE,0,vertex); 
} 

然後glDrawElements(GL_TRIANGLES,faces*3,GL_UNSIGNED_INT,vertexIndex);

1 method.This什麼glDrawElemnt給我。

2：

for(int i=0;i<trianglesNumber;i++) 
{ 
glBegin(GL_TRIANGLES); 
glNormal3f();glVertex3f(); 
glNormal3f();glVertex3f(); 
glNormal3f();glVertex3f(); 
glEnd(); 
} 

第二個方法

Answer 1

此頁給我看的方法。 http://www.opengl.org/wiki/VBO_-_just_examples

我的代碼如下。

#include"gl\glew.h" 
#include"obj-catcher.h" 
#include"gl\glut.h" 

#define ushort unsigned int 
#define BUFFER_OFFSET(i) ((char *)NULL + (i)) 

Catch A("models\\ballALL.obj"); 
int xRot=0; 
int Size=1; 
GLfloat lightPos[]={0.0f,0.0f,500.0f,10}; 
GLfloat specular[]={1.0f,1.0f,1.0f,1.0f}; 
GLfloat specref[]={1.0f,1.0f,1.0f,1.0f}; 
GLfloat ambientLight[]={1.0f,1.0f,0.0f,1.0f}; 
GLfloat spotDir[]={0.0f,0.0f,-1.0f}; 

GLuint VertexVBOID,IndexVBOID; 

struct MyVertex 
{ 
    float x, y, z; 
    Normal vn; 
    float s0, t0 , w0; 
}*pvertex; 
unsigned int *index; 
int something() 
{ 
    glEnable(GL_LIGHTING); 
    glClearColor(0.0f,0.0f,0.0f,1.0f); 
    glShadeModel(GL_SMOOTH); 
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT,ambientLight); 
    glLightfv(GL_LIGHT0,GL_DIFFUSE,ambientLight); 
    glLightfv(GL_LIGHT0,GL_SPECULAR,specular); 
    glLightfv(GL_LIGHT0,GL_POSITION,lightPos); 
    glLightf(GL_LIGHT0,GL_SPOT_CUTOFF,60.0f); 
    glEnable(GL_LIGHT0); 
    return 0; 
} 
int SetupRC() 
{ 
    glEnable(GL_DEPTH_TEST); 
    glClearDepth(1); 
    pvertex=new MyVertex [A.get_f()*3]; 
    index=new unsigned int [A.get_f()*3]; 
    for(int i=0;i<A.get_f()*3;i++) 
    { 
     index[i]=i; 
     pvertex[i].x=A.get_vertex()[A.get_vi()[i]*3];pvertex[i].y=A.get_vertex()[A.get_vi()[i]*3+1];pvertex[i].z=A.get_vertex()[A.get_vi()[i]*3+2]; 
     pvertex[i].s0=A.get_texture()[A.get_ui()[i]*3+0];pvertex[i].t0=A.get_texture()[A.get_ui()[i]*3+1];pvertex[i].w0=A.get_texture()[A.get_ui()[i]*3+2]; 
     pvertex[i].vn=A.get_normal()[A.get_vni()[i]]; 
    } 
    glGenBuffers(1, &VertexVBOID);//注意這句在原文章裏是錯的。原文章的網址在本文最下方 
    glBindBuffer(GL_ARRAY_BUFFER, VertexVBOID); 
    glBufferData(GL_ARRAY_BUFFER, sizeof(MyVertex)*3*A.get_f(), &pvertex[0].x, GL_STATIC_DRAW); 
    glGenBuffers(1, &IndexVBOID); 
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IndexVBOID); 
    glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(ushort)*3*A.get_f(), index, GL_STATIC_DRAW); 
    glBindBuffer(GL_ARRAY_BUFFER, VertexVBOID); 
    glEnableVertexAttribArray(0);                       //We like submitting vertices on stream 0 for no special reason 
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(MyVertex), BUFFER_OFFSET(0));  //VBO頂點數據在內存中的起始位置 
    glEnableVertexAttribArray(1);                       //我們把法線在編號爲1的流中提交，沒什麼特別的原因 
    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(MyVertex), BUFFER_OFFSET(12));//法線在內存中的起始位置，偏移量爲12字節 
    glEnableVertexAttribArray(2);                       //我們把紋理在編號爲2的流中提交，沒什麼特別的原因 
    glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, sizeof(MyVertex), BUFFER_OFFSET(24));//紋理在內存中的起始位置，偏移量爲24字節 
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, IndexVBOID); 
    glEnableClientState(GL_NORMAL_ARRAY); 
    glEnableClientState(GL_TEXTURE_COORD_ARRAY); 
    glNormalPointer(GL_FLOAT,sizeof(MyVertex),BUFFER_OFFSET(12)); 
    glTexCoordPointer(3,GL_FLOAT,sizeof(MyVertex),BUFFER_OFFSET(12)); 
    if(index) {delete [] index;index=NULL;} 
    if(pvertex){delete [] pvertex;pvertex=NULL;} 
    something(); 
    return 0; 
} 
void renderscene() 
{ 
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT); 
    glColor3f(1.0,1.0,1.0); 
    glPushMatrix(); 
     glRotatef(xRot++,0.0f,1.0f,0.0f); 
      glDrawElements(GL_TRIANGLES,A.get_f()*3, GL_UNSIGNED_INT, BUFFER_OFFSET(0)); 
    glPopMatrix(); 
    glutSwapBuffers(); 
} 
void TimerFunction(int value) 
{ 
    glutPostRedisplay(); 
    glutTimerFunc(33,TimerFunction,1); 
} 
void windowchange(int w,int h) 
{ 
    float fAspect; 
    if(h==0) 
     h=1; 
    glViewport(0,0,w,h); 
    fAspect=(GLfloat)w/(GLfloat)h; 
    glMatrixMode(GL_PROJECTION); 
    glLoadIdentity(); 
    glOrtho(-1*Size,Size,-1*Size,Size,-1*Size,Size); 
    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 
} 
int main(int argc,char *argv[]) 
{ 
    glutInit(&argc , argv); 
    glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB); 
    glutInitWindowSize(300,300); 
    glutCreateWindow("obj-catcher,example(for OpenGL)"); 
    glutReshapeFunc(windowchange); 
    glutDisplayFunc(renderscene); 
    glutTimerFunc(1,TimerFunction,1); 
    glewInit(); 
    SetupRC(); 
    glMatrixMode(GL_MODELVIEW); 
    glLoadIdentity(); 
    glutMainLoop(); 
    if(index) {delete [] index;index=NULL;} 
    if(pvertex){delete [] pvertex;pvertex=NULL;} 
    return 0; 
} 

感謝您的好心幫................................. ...