我的OPENGL项目照明有问题。 我使用ECLIPSE在c ++上编程。 我有一个由三角形条带构造的terrein。我的渲染代码如下:
HeightMap::~HeightMap(void) {
}
float HeightMap::getScaledGrayColor(double height) {
float fColor = NULL;
if (height == this->NODATA_value) {
return 0.0f;
}
fColor = ((255.00f / max) * height) / 255.00f;
return fColor;
}
double* HeightMap::getHeights(int rowNumber) {
rowNumber = rowNumber + 6;
ifstream fin(this->filename);
string s;
long length;
fin.seekg(0, ios::beg); // go to the first line
for (int i = 0; i < rowNumber; i++) { // loop 'till the desired line
getline(fin, s);
}
string nextToken;
getline(fin, nextToken);
StringUtils stringUtils;
vector<string> tempVec = stringUtils.split(nextToken, " ");
double* heights = new double[this->ncols];
for (int i = 0; i < tempVec.size() - 1; i++) {
heights[i] = strtod(tempVec[i].c_str(), NULL);
}
return heights;
}
void HeightMap::Render(void)
{
int x = 0;
int i = 0;
for (int i = 0, j = 0; j < nrows; i--, j++) {
//cout<<"valore di i è: "<<i<<endl;
//cout<<"valore di j è: "<<j<<endl;
double * rowHeights = this->getHeights(j);//
for (int x = 0; x < ncols; x++) {
float color = getScaledGrayColor(rowHeights[x]);
double * Quote = this->getHeights(x);
glBegin(GL_TRIANGLE_STRIP);
glColor3f(color, color, color);
//triangolo ABC
//glNormal3f((x * cellsize), (i * cellsize), 0);
glVertex3f((x * cellsize), (i * cellsize), 0); //vertice base
//glNormal3f((x * cellsize), ((i * cellsize) + cellsize), 0);
glVertex3f((x * cellsize), ((i * cellsize) + cellsize),
0);//vertice base
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+
(cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)
+ (cellsize / 2)), *Quote);//vertice altezza
//triangolo DEF
//glNormal3f((x * cellsize), (i * cellsize) + cellsize, 0);
glVertex3f((x * cellsize), (i * cellsize) + cellsize, 0);
//vertice base
//glNormal3f((x * cellsize) + cellsize, (i * cellsize) + cellsize,
0);//vertice base
glVertex3f((x * cellsize) + cellsize, (i * cellsize) + cellsize,
0);//vertice base
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+
(cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)
+ (cellsize / 2)),
*Quote);//vertice altezza
//triangolo GHI
//glNormal3f((x * cellsize) + cellsize, (i * cellsize) + cellsize,
0); //vertice base
glVertex3f((x * cellsize) + cellsize, (i * cellsize) + cellsize,
0); //vertice base
//glNormal3f((x * cellsize) + cellsize, i * cellsize, 0);//vertice
base
glVertex3f((x * cellsize) + cellsize, i * cellsize, 0);//vertice
base
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+
(cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)
+ (cellsize / 2)),
*Quote);//vertice altezza
//triangolo LMN
//glNormal3f((x * cellsize), (i * cellsize), 0); //vertice base
glVertex3f((x * cellsize), (i * cellsize), 0); //vertice base
//glNormal3f((x * cellsize) + cellsize, (i * cellsize),
0);//vertice base
glVertex3f((x * cellsize) + cellsize, (i * cellsize), 0);//vertice
base
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+
(cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)
+ (cellsize / 2)),
*Quote);//vertice altezza
glEnd();
}
//}
}
}
我尝试使用普通的顶点,但我不知道如何计算glnormal函数的参数。 然后我必须使用正常面部。 你能帮我解决这个问题吗?
是的,我需要正常的脸,然后我必须通过顶点做正常: 对于正常的面对我这样做 void HeightMap :: Render(void) { int x = 0; int i = 0; glPushMatrix(); glRotatef(angle,xrot,yrot,zrot); //旋转对象 cout&lt;&lt;“valore dinrowsè:”&lt; getHeights(j); float vectorba [3] = {0.0,0.0,0.0}; float vectorcb [3] = {0.0,0.0,0.0}; float xnormal = 0.0; float ynormal = 0.0; float znormal = 0.0; float len = 0.0;
for (int x = 0; x < ncols; x++) {
//if (rowHeights[x] != this->NODATA_value) {
float color = getScaledGrayColor(rowHeights[x]);
double * Quote = this->getHeights(x);
glBegin(GL_TRIANGLE_STRIP);
glColor3f(color, color, color);
//triangolo ABC
//inizio normal
vectorba[0]={(x * cellsize)-(x * cellsize)};
vectorba[1]={((i * cellsize) + cellsize)-(i * cellsize)};
vectorcb[0]={((x * cellsize) + (cellsize / 2))-(x * cellsize)};
vectorcb[1]={((i * cellsize) + (cellsize / 2))-((i * cellsize) +cellsize)};
vectorcb[2]=*Quote;
// calculate the cross product and place the resulting vector
// into the variable xnormal,ynormal e znormal
xnormal = (vectorba[1] * vectorcb[2]) - (vectorba[2] * vectorcb[1]);
ynormal = (vectorba[2] * vectorcb[0]) - (vectorba[0] * vectorcb[2]);
znormal = (vectorba[0] * vectorcb[1]) - (vectorba[1] * vectorcb[0]);
//fine normal
//inizio normalize
// calculate the length of the vector
len = (float)(sqrt((xnormal * xnormal) + (ynormal * ynormal) + (znormal * znormal)));
// avoid division by 0
if (len == 0.0f)
len = 1.0f;
// reduce to unit size
xnormal /= len;
ynormal /= len;
znormal /= len;
//fine normalize
//glNormal3f((x * cellsize), (i * cellsize), 0); //normal per vertex. controllare la formula
glVertex3f((x * cellsize), (i * cellsize), 0); //vertice base A
//glNormal3f((x * cellsize), ((i * cellsize) + cellsize), 0);
glVertex3f((x * cellsize), ((i * cellsize) + cellsize), 0);//vertice base B
glNormal3f(xnormal, ynormal, znormal); //normal per face
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)
+ (cellsize / 2)), *Quote);//vertice altezza C
//triangolo DEF
//inizio normal
vectorba[0]={(x * cellsize) + cellsize-(x * cellsize)};
vectorba[1]={((i * cellsize) + cellsize)-((i * cellsize) + cellsize)};
vectorcb[0]={((x * cellsize) + (cellsize / 2))-(x * cellsize) + cellsize};
vectorcb[1]={((i * cellsize)+ (cellsize / 2))-((i * cellsize) + cellsize)};
vectorcb[2]=*Quote;
// calculate the cross product and place the resulting vector
// into the variable xnormal,ynormal e znormal
xnormal = (vectorba[1] * vectorcb[2]) - (vectorba[2] * vectorcb[1]);
ynormal = (vectorba[2] * vectorcb[0]) - (vectorba[0] * vectorcb[2]);
znormal = (vectorba[0] * vectorcb[1]) - (vectorba[1] * vectorcb[0]);
//fine normal
//inizio normalize
// calculate the length of the vector
len = (float)(sqrt((xnormal * xnormal) + (ynormal * ynormal) + (znormal * znormal)));
// avoid division by 0
if (len == 0.0f)
len = 1.0f;
// reduce to unit size
xnormal /= len;
ynormal /= len;
znormal /= len;
//fine normalize
//glNormal3f((x * cellsize), (i * cellsize) + cellsize, 0);
glVertex3f((x * cellsize), (i * cellsize) + cellsize, 0); //vertice base D
//glNormal3f((x * cellsize) + cellsize, (i * cellsize) + cellsize, 0);//vertice base
glVertex3f((x * cellsize) + cellsize, (i * cellsize) + cellsize, 0);//vertice base E
glNormal3f(xnormal, ynormal, znormal); //normal per face
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza F
//triangolo GHI
//inizio normal
vectorba[0]={(x * cellsize) + cellsize-(x * cellsize) + cellsize};
vectorba[1]={i * cellsize-(i * cellsize) + cellsize};
vectorcb[0]={((x * cellsize) + (cellsize / 2))-(x * cellsize) + cellsize};
vectorcb[1]={((i * cellsize)+ (cellsize / 2))-(i * cellsize)};
vectorcb[2]=*Quote;
// calculate the cross product and place the resulting vector
// into the variable xnormal,ynormal e znormal
xnormal = (vectorba[1] * vectorcb[2]) - (vectorba[2] * vectorcb[1]);
ynormal = (vectorba[2] * vectorcb[0]) - (vectorba[0] * vectorcb[2]);
znormal = (vectorba[0] * vectorcb[1]) - (vectorba[1] * vectorcb[0]);
//fine normal
//inizio normalize
// calculate the length of the vector
len = (float)(sqrt((xnormal * xnormal) + (ynormal * ynormal) + (znormal * znormal)));
// avoid division by 0
if (len == 0.0f)
len = 1.0f;
// reduce to unit size
xnormal /= len;
ynormal /= len;
znormal /= len;
//fine normalize
//glNormal3f((x * cellsize) + cellsize, (i * cellsize) + cellsize, 0); //vertice base
glVertex3f((x * cellsize) + cellsize, (i * cellsize) + cellsize, 0); //vertice base G
//glNormal3f((x * cellsize) + cellsize, i * cellsize, 0);//vertice base
glVertex3f((x * cellsize) + cellsize, i * cellsize, 0);//vertice base H
glNormal3f(xnormal, ynormal, znormal); //normal per face
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza I
//triangolo LMN
//inizio normal
vectorba[0]={(x * cellsize) + cellsize-(x * cellsize)};
vectorba[1]={(i * cellsize)-(i * cellsize)};
vectorcb[0]={((x * cellsize) + (cellsize / 2))-(x * cellsize) + cellsize};
vectorcb[1]={((i * cellsize)+ (cellsize / 2))-(i * cellsize)};
vectorcb[2]=*Quote;
// calculate the cross product and place the resulting vector
// into the variable xnormal,ynormal e znormal
xnormal = (vectorba[1] * vectorcb[2]) - (vectorba[2] * vectorcb[1]);
ynormal = (vectorba[2] * vectorcb[0]) - (vectorba[0] * vectorcb[2]);
znormal = (vectorba[0] * vectorcb[1]) - (vectorba[1] * vectorcb[0]);
//fine normal
//inizio normalize
// calculate the length of the vector
len = (float)(sqrt((xnormal * xnormal) + (ynormal * ynormal) + (znormal * znormal)));
// avoid division by 0
if (len == 0.0f)
len = 1.0f;
// reduce to unit size
xnormal /= len;
ynormal /= len;
znormal /= len;
//fine normalize
//glNormal3f((x * cellsize), (i * cellsize), 0); //vertice base
glVertex3f((x * cellsize), (i * cellsize), 0); //vertice base L
//glNormal3f((x * cellsize) + cellsize, (i * cellsize), 0);//vertice base
glVertex3f((x * cellsize) + cellsize, (i * cellsize), 0);//vertice base M
glNormal3f(xnormal, ynormal, znormal); //normal per face
//glNormal3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza
glVertex3f(((x * cellsize) + (cellsize / 2)), ((i * cellsize)+ (cellsize / 2)), *Quote);//vertice altezza N
glEnd();
}
//}
}
glPopMatrix();
}
配方是对的? 如何使用normal和normalize函数转换Render?
答案 0 :(得分:2)
如果我明白了,你想要面对正常吗?
如果你有三角形点,你可以计算每个面的法线。
看看这个:
http://www.opengl.org/wiki/Calculating_a_Surface_Normal
可以使用面之间的平均法线计算顶点法线。