刚刚开始写光线跟踪，今天准备实现阴影的效果，但是发现了一些问题。
先上图：

球体自身的阴影叠加在了球体上方，
并且来自其他球体的影子显示也不正确。我想了很久也没发现问题在哪。
还请各位前辈指点一下。

相关代码：

RGBColor Phong::Shade(ShadeRec &sr) { Vector3D wo(-sr.m_ray.d); RGBColor L = m_ambientBRDF->rho(sr, wo) * sr.m_world.m_ambient->L(sr); int lightsNum = sr.m_world.m_lights.size(); for (int i = 0; i < lightsNum; ++i) { Vector3D wi = sr.m_world.m_lights[i]->GetDirection(sr); float ndotwi = sr.m_hitPointNormal * wi; if(ndotwi > 0.0) { bool inShadow = false; if(sr.m_world.m_lights[i]->castsShadow()) { Ray shadowRay((sr.m_worldHitPoint + kEpsilon), wi); inShadow = sr.m_world.m_lights[i]->inShadow(shadowRay, sr); } if(!inShadow) { L += (m_diffuseBRDF->fr(sr, wo, wi) + m_specularBRDF->fr(sr, wo, wi)) * sr.m_world.m_lights[i]->L(sr) * ndotwi; } } } return L; } bool PointLight::inShadow(const Ray &shadowray, const ShadeRec &sr) { float ht(sr.m_t); float t; int ObjectNum = sr.m_world.m_objects.size(); float d = m_location.distance(shadowray.o); for (int i = 0; i < ObjectNum; ++i) { if(sr.m_world.m_objects[i]->ShadowHit(shadowray, t) && t < d) { return true; } } return false; } bool Sphere::ShadowHit(const Ray &ray, float &tmin) const { const double ep = 0.01; double t0, t1; Vector3D oc = ray.o - center; double a = ray.d * ray.d; double b = 2.0 * oc * ray.d; double c = oc * oc - radius * radius; double disc = b * b - 4.0 * a * c; if (disc < 0.0) { return false; } double e = sqrt(disc); double denom = 2.0 * a; t0 = (-b - e) / denom; if (t0 > ep) { tmin = t0; return true; } t1 = (-b + e) / denom; if (t1 > ep) { tmin = t1; return true; } return true; }