c – 为什么光线跟踪器将球体渲染为椭圆形？

在过去的几天里,我第一次一直在攻击光线跟踪器.然而,有一些困扰我的怪癖,我真的不知道如何解决.从一开始就存在的是场景中球体的形状 – 渲染时,它们实际上看起来像椭圆形.当然,场景中有透视,但最终的形状看起来仍然很奇怪.我附上了一个样本渲染,我所遇到的问题在图像左下角的反射球上特别明显.

我真的不知道是什么原因引起的.它可能是光线球体交叉代码,如下所示：

bool Sphere::intersect(Ray ray,glm::vec3& hitPoint) {
//Compute A,B and C coefficients
float a = glm::dot(ray.dir,ray.dir);
float b = 2.0 * glm::dot(ray.dir,ray.org-pos);
float c = glm::dot(ray.org-pos,ray.org-pos) - (rad * rad);

// Find discriminant
float disc = b * b - 4 * a * c;

// if Discriminant is negative there are no real roots,so return
// false as ray misses sphere
if (disc < 0)
    return false;

// compute q
float distSqrt = sqrt(disc);
float q;
if (b < 0)
    q = (-b - distSqrt)/2.0;
else
    q = (-b + distSqrt)/2.0;

// compute t0 and t1
float t0 = q / a;
float t1 = c / q;

// make sure t0 is smaller than t1
if (t0 > t1) {
    // if t0 is bigger than t1 swap them around
    float temp = t0;
    t0 = t1;
    t1 = temp;
}

// if t1 is less than zero,the object is in the ray's negative direction
// and consequently the ray misses the sphere
if (t1 < 0)
    return false;

// if t0 is less than zero,thE intersection point is at t1
if (t0 < 0) {
    hitPoint = ray.org + t1 * ray.dir;
    return true;
} else { // else thE intersection point is at t0
    hitPoint = ray.org + t0 * ray.dir;
    return true;
    }
}

或者它可能是另一回事.有没有人有想法？非常感谢！