double Camera::extract_focal_length(const double film_width) const
{
const double DefaultFocalLength = 0.035; // in meters
const double DefaultHFov = 54.0; // in degrees
if (has_param("focal_length"))
{
if (has_param("horizontal_fov"))
{
RENDERER_LOG_WARNING(
"while defining camera \"%s\": the parameter \"horizontal_fov\" "
"has precedence over \"focal_length\".",
get_path().c_str());
const double hfov = get_greater_than_zero("horizontal_fov", DefaultHFov);
return hfov_to_focal_length(film_width, hfov);
}
else
{
return get_greater_than_zero("focal_length", DefaultFocalLength);
}
}
else if (has_param("horizontal_fov"))
{
const double hfov = get_greater_than_zero("horizontal_fov", DefaultHFov);
return hfov_to_focal_length(film_width, hfov);
}
else
{
RENDERER_LOG_ERROR(
"while defining camera \"%s\": no \"horizontal_fov\" or \"focal_length\" parameter found; "
"using default focal length value \"%f\".",
get_path().c_str(),
DefaultFocalLength);
return DefaultFocalLength;
}
}
Vector2d Camera::extract_film_dimensions() const
{
const Vector2d DefaultFilmDimensions(0.025, 0.025); // in meters
const double DefaultAspectRatio =
DefaultFilmDimensions[0] / DefaultFilmDimensions[1];
Vector2d film_dimensions;
if (has_params("film_width", "film_height"))
{
film_dimensions[0] = get_greater_than_zero("film_width", DefaultFilmDimensions[0]);
film_dimensions[1] = get_greater_than_zero("film_height", DefaultFilmDimensions[1]);
}
else if (has_params("film_width", "aspect_ratio"))
{
const double aspect_ratio = get_greater_than_zero("aspect_ratio", DefaultAspectRatio);
film_dimensions[0] = get_greater_than_zero("film_width", DefaultFilmDimensions[0]);
film_dimensions[1] = film_dimensions[0] / aspect_ratio;
}
else if (has_params("film_height", "aspect_ratio"))
{
const double aspect_ratio = get_greater_than_zero("aspect_ratio", DefaultAspectRatio);
film_dimensions[1] = get_greater_than_zero("film_height", DefaultFilmDimensions[1]);
film_dimensions[0] = film_dimensions[1] * aspect_ratio;
}
else
{
film_dimensions =
m_params.get_required<Vector2d>("film_dimensions", DefaultFilmDimensions);
if (film_dimensions[0] <= 0.0 || film_dimensions[1] <= 0.0)
{
RENDERER_LOG_ERROR(
"while defining camera \"%s\": invalid value \"%f %f\" for parameter \"%s\", "
"using default value \"%f %f\".",
get_name(),
film_dimensions[0],
film_dimensions[1],
"film_dimensions",
DefaultFilmDimensions[0],
DefaultFilmDimensions[1]);
film_dimensions = DefaultFilmDimensions;
}
}
return film_dimensions;
}
double Camera::extract_f_stop() const
{
const double DefaultFStop = 8.0;
return get_greater_than_zero("f_stop", DefaultFStop);
}
