我已经用10000个顶点（100x100）绘制了一个三角网格，它将成为一个草地。我使用gldrawelements（）进行绘制。我一整天都在寻找如何计算这个模型的法线，但仍然不理解。每个顶点有自己的法线还是每个三角形有自己的法线？能否指引我如何修改代码来加入法线？
struct vertices {
GLfloat x;
GLfloat y;
GLfloat z;
}vertices[10000];
GLuint indices[60000];
/*
99..9999
98..9998
........
01..9901
00..9900
*/
void CreateEnvironment() {
int count=0;
for (float x=0;x<10.0;x+=.1) {
for (float z=0;z<10.0;z+=.1) {
vertices[count].x=x;
vertices[count].y=0;
vertices[count].z=z;
count++;
}
}
count=0;
for (GLuint a=0;a<99;a++){
for (GLuint b=0;b<99;b++){
GLuint v1=(a*100)+b;indices[count]=v1;count++;
GLuint v2=(a*100)+b+1;indices[count]=v2;count++;
GLuint v3=(a*100)+b+100;indices[count]=v3;count++;
}
}
count=30000;
for (GLuint a=0;a<99;a++){
for (GLuint b=0;b<99;b++){
indices[count]=(a*100)+b+100;count++;//9998
indices[count]=(a*100)+b+1;count++;//9899
indices[count]=(a*100)+b+101;count++;//9999
}
}
}
void ShowEnvironment(){
//ground
glPushMatrix();
GLfloat GroundAmbient[]={0.0,0.5,0.0,1.0};
glMaterialfv(GL_FRONT,GL_AMBIENT,GroundAmbient);
glEnableClientState(GL_VERTEX_ARRAY);
glIndexPointer( GL_UNSIGNED_BYTE, 0, indices );
glVertexPointer(3,GL_FLOAT,0,vertices);
glDrawElements(GL_TRIANGLES,60000,GL_UNSIGNED_INT,indices);
glDisableClientState(GL_VERTEX_ARRAY);
glPopMatrix();
}
编辑1 这是我编写的代码。我只是使用了数组而不是向量，并将所有法线存储在名为normals的结构体中。然而，它仍然不起作用。我在*indices处收到一个未处理的异常。
struct Normals {
GLfloat x;
GLfloat y;
GLfloat z;
}normals[20000];
Normals* normal = normals;
//***************************************ENVIRONMENT*************************************************************************
struct vertices {
GLfloat x;
GLfloat y;
GLfloat z;
}vertices[10000];
GLuint indices[59403];
/*
99..9999
98..9998
........
01..9901
00..9900
*/
void CreateEnvironment() {
int count=0;
for (float x=0;x<10.0;x+=.1) {
for (float z=0;z<10.0;z+=.1) {
vertices[count].x=x;
vertices[count].y=rand()%2-2;;
vertices[count].z=z;
count++;
}
}
//calculate normals
GLfloat vector1[3];//XYZ
GLfloat vector2[3];//XYZ
count=0;
for (int x=0;x<9900;x+=100){
for (int z=0;z<99;z++){
vector1[0]= vertices[x+z].x-vertices[x+z+1].x;//vector1x
vector1[1]= vertices[x+z].y-vertices[x+z+1].y;//vector1y
vector1[2]= vertices[x+z].z-vertices[x+z+1].z;//vector1z
vector2[0]= vertices[x+z+1].x-vertices[x+z+100].x;//vector2x
vector2[1]= vertices[x+z+1].y-vertices[x+z+100].y;//vector2y
vector2[2]= vertices[x+z+1].z-vertices[x+z+100].z;//vector2z
normals[count].x= vector1[1] * vector2[2]-vector1[2]*vector2[1];
normals[count].y= vector1[2] * vector2[0] - vector1[0] * vector2[2];
normals[count].z= vector1[0] * vector2[1] - vector1[1] * vector2[0];count++;
}
}
count=10000;
for (int x=100;x<10000;x+=100){
for (int z=0;z<99;z++){
vector1[0]= vertices[x+z].x-vertices[x+z+1].x;//vector1x -- JUST ARRAYS
vector1[1]= vertices[x+z].y-vertices[x+z+1].y;//vector1y
vector1[2]= vertices[x+z].z-vertices[x+z+1].z;//vector1z
vector2[0]= vertices[x+z+1].x-vertices[x+z-100].x;//vector2x
vector2[1]= vertices[x+z+1].y-vertices[x+z-100].y;//vector2y
vector2[2]= vertices[x+z+1].z-vertices[x+z-100].z;//vector2z
normals[count].x= vector1[1] * vector2[2]-vector1[2]*vector2[1];
normals[count].y= vector1[2] * vector2[0] - vector1[0] * vector2[2];
normals[count].z= vector1[0] * vector2[1] - vector1[1] * vector2[0];count++;
}
}
count=0;
for (GLuint a=0;a<99;a++){
for (GLuint b=0;b<99;b++){
GLuint v1=(a*100)+b;indices[count]=v1;count++;
GLuint v2=(a*100)+b+1;indices[count]=v2;count++;
GLuint v3=(a*100)+b+100;indices[count]=v3;count++;
}
}
count=30000;
for (GLuint a=0;a<99;a++){
for (GLuint b=0;b<99;b++){
indices[count]=(a*100)+b+100;count++;//9998
indices[count]=(a*100)+b+1;count++;//9899
indices[count]=(a*100)+b+101;count++;//9999
}
}
}
void ShowEnvironment(){
//ground
glPushMatrix();
GLfloat GroundAmbient[]={0.0,0.5,0.0,1.0};
GLfloat GroundDiffuse[]={1.0,0.0,0.0,1.0};
glMaterialfv(GL_FRONT,GL_AMBIENT,GroundAmbient);
glMaterialfv(GL_FRONT,GL_DIFFUSE,GroundDiffuse);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_NORMAL_ARRAY);
glNormalPointer( GL_FLOAT, 0, normal);
glVertexPointer(3,GL_FLOAT,0,vertices);
glDrawElements(GL_TRIANGLES,60000,GL_UNSIGNED_INT,indices);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_NORMAL_ARRAY);
glPopMatrix();
}
//***************************************************************************************************************************
glDrawElements(GL_TRIANGLES,60000,GL_UNSIGNED_INT,indices);运行时将会超出您的包含59403个元素的indices数组的末尾。 - genpfault