const ShadingPoint& Tracer::do_trace(
const Vector3d& origin,
const Vector3d& direction,
const double time,
const ShadingRay::Type ray_type,
const ShadingRay::DepthType ray_depth,
double& transmission,
const ShadingPoint* parent_shading_point)
{
transmission = 1.0;
const ShadingPoint* shading_point_ptr = parent_shading_point;
size_t shading_point_index = 0;
Vector3d point = origin;
size_t iterations = 0;
while (true)
{
// Put a hard limit on the number of iterations.
if (++iterations >= m_max_iterations)
{
RENDERER_LOG_WARNING(
"reached hard iteration limit (%s), breaking trace loop.",
pretty_int(m_max_iterations).c_str());
break;
}
// Construct the visibility ray.
const ShadingRay ray(
point,
direction,
time,
m_ray_dtime,
ray_type,
ray_depth); // ray depth does not increase when passing through an alpha-mapped surface
// Trace the ray.
m_shading_points[shading_point_index].clear();
m_intersector.trace(
ray,
m_shading_points[shading_point_index],
shading_point_ptr);
// Update the pointers to the shading points.
shading_point_ptr = &m_shading_points[shading_point_index];
shading_point_index = 1 - shading_point_index;
// Stop if the ray escaped the scene.
if (!shading_point_ptr->hit())
break;
// Retrieve the material at the shading point.
const Material* material = shading_point_ptr->get_material();
if (material == 0)
break;
Alpha alpha;
evaluate_alpha(*material, *shading_point_ptr, alpha);
// Stop at the first fully opaque occluder.
if (alpha[0] >= 1.0f)
break;
// Update the transmission factor.
transmission *= 1.0 - static_cast<double>(alpha[0]);
// Stop once we hit full opacity.
if (transmission < m_transmission_threshold)
break;
// Move past this partial occluder.
point = shading_point_ptr->get_point();
}
return *shading_point_ptr;
}
const ShadingPoint& Tracer::do_trace_between(
const Vector3d& origin,
const Vector3d& target,
const ShadingRay::Time& ray_time,
const VisibilityFlags::Type ray_flags,
const ShadingRay::DepthType ray_depth,
float& transmission,
const ShadingPoint* parent_shading_point)
{
transmission = 1.0f;
const ShadingPoint* shading_point_ptr = parent_shading_point;
size_t shading_point_index = 0;
Vector3d point = origin;
size_t iterations = 0;
while (true)
{
// Put a hard limit on the number of iterations.
if (++iterations >= m_max_iterations)
{
RENDERER_LOG_WARNING(
"reached hard iteration limit (%s), breaking trace loop.",
pretty_int(m_max_iterations).c_str());
break;
}
// Construct the visibility ray.
const Vector3d direction = target - point;
const double dist = norm(direction);
const ShadingRay ray(
point,
direction / dist,
0.0, // ray tmin
dist * (1.0 - 1.0e-6), // ray tmax
ray_time,
ray_flags,
ray_depth); // ray depth does not increase when passing through an alpha-mapped surface
// Trace the ray.
m_shading_points[shading_point_index].clear();
m_intersector.trace(
ray,
m_shading_points[shading_point_index],
shading_point_ptr);
// Update the pointers to the shading points.
shading_point_ptr = &m_shading_points[shading_point_index];
shading_point_index = 1 - shading_point_index;
// Stop if the ray reached the target point.
if (!shading_point_ptr->hit())
break;
// Retrieve the material at the shading point.
const Material* material = shading_point_ptr->get_material();
if (material == 0)
break;
// Evaluate the alpha map at the shading point.
Alpha alpha;
evaluate_alpha(*material, *shading_point_ptr, alpha);
// Stop at the first fully opaque occluder.
if (alpha[0] >= 1.0f)
break;
// Update the transmission factor.
transmission *= 1.0f - alpha[0];
// Stop once we hit full opacity.
if (transmission < m_transmission_threshold)
break;
// Move past this partial occluder.
point = shading_point_ptr->get_point();
}
return *shading_point_ptr;
}
