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slightly improved accuracy of intersection computations in the the cylinder shape

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Wenzel Jakob 2014-03-20 12:30:28 +01:00
parent cf4ba27ee9
commit 0c20766291
1 changed files with 27 additions and 23 deletions
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50
src/shapes/cylinder.cpp
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@ -131,32 +131,32 @@ public:
/* Transform into the local coordinate system and normalize */ /* Transform into the local coordinate system and normalize */
m_worldToObject(_ray, ray); m_worldToObject(_ray, ray);
const Float const double
ox = ray.o.x, ox = ray.o.x,
oy = ray.o.y, oy = ray.o.y,
dx = ray.d.x, dx = ray.d.x,
dy = ray.d.y; dy = ray.d.y;
const Float A = dx*dx + dy*dy; const double A = dx*dx + dy*dy;
const Float B = 2 * (dx*ox + dy*oy); const double B = 2 * (dx*ox + dy*oy);
const Float C = ox*ox + oy*oy - m_radius*m_radius; const double C = ox*ox + oy*oy - m_radius*m_radius;
Float nearT, farT; double nearT, farT;
if (!solveQuadratic(A, B, C, nearT, farT)) if (!solveQuadraticDouble(A, B, C, nearT, farT))
return false; return false;
if (!(nearT <= maxt && farT >= mint)) /* NaN-aware conditionals */ if (!(nearT <= maxt && farT >= mint)) /* NaN-aware conditionals */
return false; return false;
const Float zPosNear = ray.o.z + ray.d.z * nearT; const double zPosNear = ray.o.z + ray.d.z * nearT;
const Float zPosFar = ray.o.z + ray.d.z * farT; const double zPosFar = ray.o.z + ray.d.z * farT;
if (zPosNear >= 0 && zPosNear <= m_length && nearT >= mint) { if (zPosNear >= 0 && zPosNear <= m_length && nearT >= mint) {
t = nearT; t = (Float) nearT;
} else if (zPosFar >= 0 && zPosFar <= m_length) { } else if (zPosFar >= 0 && zPosFar <= m_length) {
if (farT > maxt) if (farT > maxt)
return false; return false;
t = farT; t = (Float) farT;
} else { } else {
return false; return false;
} }
@ -170,25 +170,25 @@ public:
/* Transform into the local coordinate system and normalize */ /* Transform into the local coordinate system and normalize */
m_worldToObject(_ray, ray); m_worldToObject(_ray, ray);
const Float const double
ox = ray.o.x, ox = ray.o.x,
oy = ray.o.y, oy = ray.o.y,
dx = ray.d.x, dx = ray.d.x,
dy = ray.d.y; dy = ray.d.y;
const Float A = dx*dx + dy*dy; const double A = dx*dx + dy*dy;
const Float B = 2 * (dx*ox + dy*oy); const double B = 2 * (dx*ox + dy*oy);
const Float C = ox*ox + oy*oy - m_radius*m_radius; const double C = ox*ox + oy*oy - m_radius*m_radius;
Float nearT, farT; double nearT, farT;
if (!solveQuadratic(A, B, C, nearT, farT)) if (!solveQuadraticDouble(A, B, C, nearT, farT))
return false; return false;
if (nearT > maxt || farT < mint) if (nearT > maxt || farT < mint)
return false; return false;
const Float zPosNear = ray.o.z + ray.d.z * nearT; const double zPosNear = ray.o.z + ray.d.z * nearT;
const Float zPosFar = ray.o.z + ray.d.z * farT; const double zPosFar = ray.o.z + ray.d.z * farT;
if (zPosNear >= 0 && zPosNear <= m_length && nearT >= mint) { if (zPosNear >= 0 && zPosNear <= m_length && nearT >= mint) {
return true; return true;
} else if (zPosFar >= 0 && zPosFar <= m_length && farT <= maxt) { } else if (zPosFar >= 0 && zPosFar <= m_length && farT <= maxt) {
@ -201,8 +201,8 @@ public:
void fillIntersectionRecord(const Ray &ray, void fillIntersectionRecord(const Ray &ray,
const void *temp, Intersection &its) const { const void *temp, Intersection &its) const {
its.p = ray(its.t); its.p = ray(its.t);
Point local = m_worldToObject(its.p); Point local = m_worldToObject(its.p);
Float phi = std::atan2(local.y, local.x); Float phi = std::atan2(local.y, local.x);
if (phi < 0) if (phi < 0)
phi += 2*M_PI; phi += 2*M_PI;
@ -214,11 +214,15 @@ public:
its.shape = this; its.shape = this;
its.dpdu = m_objectToWorld(dpdu); its.dpdu = m_objectToWorld(dpdu);
its.dpdv = m_objectToWorld(dpdv); its.dpdv = m_objectToWorld(dpdv);
its.geoFrame.n = Normal(normalize(cross(its.dpdu, its.dpdv)));
if (m_flipNormals)
its.geoFrame.n *= -1;
its.geoFrame.s = normalize(its.dpdu); its.geoFrame.s = normalize(its.dpdu);
its.geoFrame.t = normalize(its.dpdv); its.geoFrame.t = normalize(its.dpdv);
its.geoFrame.n = Normal(cross(its.geoFrame.s, its.geoFrame.t));
/* Migitate roundoff error issues by a normal shift of the computed intersection point */
its.p += its.geoFrame.n * (m_radius - std::sqrt(local.x*local.x+local.y*local.y));
if (m_flipNormals)
its.geoFrame.n *= -1;
its.shFrame = its.geoFrame; its.shFrame = its.geoFrame;
its.wi = its.toLocal(-ray.d); its.wi = its.toLocal(-ray.d);
its.hasUVPartials = false; its.hasUVPartials = false;
@ -378,7 +382,7 @@ public:
Float alpha = ellipseAxes[0][j], beta = ellipseAxes[1][j]; Float alpha = ellipseAxes[0][j], beta = ellipseAxes[1][j];
Float tmp = 1 / std::sqrt(alpha*alpha + beta*beta); Float tmp = 1 / std::sqrt(alpha*alpha + beta*beta);
Float cosTheta = alpha * tmp, sinTheta = beta*tmp; Float cosTheta = alpha * tmp, sinTheta = beta*tmp;
Point p1 = ellipseCenter + cosTheta*ellipseAxes[0] + sinTheta*ellipseAxes[1]; Point p1 = ellipseCenter + cosTheta*ellipseAxes[0] + sinTheta*ellipseAxes[1];
Point p2 = ellipseCenter - cosTheta*ellipseAxes[0] - sinTheta*ellipseAxes[1]; Point p2 = ellipseCenter - cosTheta*ellipseAxes[0] - sinTheta*ellipseAxes[1];