制作光线追踪器,代码失败了,所以我决定重做整个事情并更改对象的逻辑,但是由于某种原因,它一直给我一个错误,并且我已经尝试对其进行多次编辑。 ImageMagick给我一个错误,说没有足够的数据产生ppm除了关于对象的一点点之外,ppm的产生方式的主要逻辑没有太大变化,因此我无法真正弄清楚错误在哪里。main.cpp
vec color(const ray& r, float t, vec a, vec centre)
{
vector <Light> lighting;
lighting.push_back(Light(vec(0, 0, 50), vec(0, 0, -1)));
vec totalLight{0, 0, 0};
for(int i = 0; i <lighting.size(); i++){
if(t > 0.0){
vec hit = unit_vector(r.p_at_par(t) - centre);
vec L = unit_vector(lighting[i].position() - r.p_at_par(t));
vec R = L - 2.0*dot(L, hit)*hit;
vec S = vec(1, 1, 1)*pow(max(0.f, dot(R, vec(0, 0, -1))), 50);//Specular component
vec D = (a * max(0.f, dot(L, hit)) * 1.0);//Diffuse component
totalLight += S + D;
return totalLight;
}
}
}
float clamp(float a)
{
return (a > 255)? 255: (a < 0)? 0: a;
}
int main()
{
const int w = 200, h = 100;
FILE *fp;
fp = fopen("img.ppm", "wb");
fprintf(fp, "P6\n%d %d\n255\n", w, h);
vec lower_corner(-2.0, -1.0, -1.0);
vec horizontal(4.0, 0.0, 0.0);
vec vertical(0.0, 2.0, 0.0);
vec origin(0.0, 0.0, 0.0);
vector <sphere> objects;
objects.push_back(sphere(vec(0,-100.5,-1), 100, vec(0, 1, 0)));
objects.push_back(sphere(vec(0, 0, -1), 0.5, vec(1, 0, 0)));
objects.push_back(sphere(vec(5, 5,-2), 3, vec(1, 0, 0)));
for(int j = h - 1; j >= 0; j--)
{
for(int i = 0; i < w; i++)
{
vec col(0, 0, 0);
static unsigned char pixel[3];
sphere* ClosestObject = NULL;
float u = float(i + random_double())/float(w);
float v = float(j + random_double())/float(h);
ray r(origin, lower_corner + u*horizontal + v*vertical);
float t = 0.0;
float t_near = 200000.0;
vec pixelColor(0.52 , 0.52 ,0.48);
for(int j = 0; j < objects.size(); j++)
{
if(t = objects[j].intersect(r))
{
if(t < t_near)
{
ClosestObject = &objects[j];
t_near = t;
}
}
if( t = 200000.0)
col = pixelColor;
else
col = color(r, t, ClosestObject->color, ClosestObject->centre);
pixel[0] = int(clamp(col.r() * 255));
pixel[1] = int(clamp(col.g() * 255));
pixel[2] = int(clamp(col.b() * 255));
fwrite(pixel, 3, 1, fp);
}
}
fclose(fp);
return 0;
}
}
实际上是一个评论,但有太多文字……
您的缩进已损坏。
因此,您没有注意到return 0;
出现在外部for
循环中,这是:
for(int j = h - 1; j >= 0; j--)
{
结尾为:
fclose(fp);
return 0;
}
另外,
fwrite(pixel, 3, 1, fp);
出现在最内部的循环中
for (int j = 0; j < objects.size(); j++)
恕我直言也是错的。
因此,生成的.ppm
文件声称具有w
×h
像素,但提供了w
×objects.size()
像素。
如果objects.size() < h
(我希望的那样),那么.ppm
文件中的像素将太少,ImageMagick将注意到并抱怨。
您的源代码,在我的VS2017中自动格式化:
int main()
{
const int w = 200, h = 100;
FILE *fp;
fp = fopen("img.ppm", "wb");
fprintf(fp, "P6\n%d %d\n255\n", w, h);
vec lower_corner(-2.0, -1.0, -1.0);
vec horizontal(4.0, 0.0, 0.0);
vec vertical(0.0, 2.0, 0.0);
vec origin(0.0, 0.0, 0.0);
vector <sphere> objects;
objects.push_back(sphere(vec(0, -100.5, -1), 100, vec(0, 1, 0)));
objects.push_back(sphere(vec(0, 0, -1), 0.5, vec(1, 0, 0)));
objects.push_back(sphere(vec(5, 5, -2), 3, vec(1, 0, 0)));
for (int j = h - 1; j >= 0; j--)
{
for (int i = 0; i < w; i++)
{
vec col(0, 0, 0);
static unsigned char pixel[3];
sphere* ClosestObject = NULL;
float u = float(i + random_double()) / float(w);
float v = float(j + random_double()) / float(h);
ray r(origin, lower_corner + u * horizontal + v * vertical);
float t = 0.0;
float t_near = 200000.0;
vec pixelColor(0.52, 0.52, 0.48);
for (int j = 0; j < objects.size(); j++)
{
if (t = objects[j].intersect(r))
{
if (t < t_near)
{
ClosestObject = &objects[j];
t_near = t;
}
}
if (t = 200000.0)
col = pixelColor;
else
col = color(r, t, ClosestObject->color, ClosestObject->centre);
pixel[0] = int(clamp(col.r() * 255));
pixel[1] = int(clamp(col.g() * 255));
pixel[2] = int(clamp(col.b() * 255));
fwrite(pixel, 3, 1, fp);
}
}
fclose(fp);
return 0;
}
}
[请检查缩进并正确放置闭合的花括号。然后它应该像以前一样工作...