Files

Romain Guy a4a1bf07aa Use our own constants instead of M_PI, M_*, etc. (#1733 )

These constants are not part of the standard. We instead use our own
constexpr definitions in the filament::math namespace, as part of
the scalar.h include.

2019-10-02 15:31:38 -07:00

data

Give specular-color the ability to compute f82 (or other angles) (#1443 )

2019-07-26 08:56:24 -10:00

src

Use our own constants instead of M_PI, M_*, etc. (#1733 )

2019-10-02 15:31:38 -07:00

CMakeLists.txt

Make CMake 3.10 the minimum version, add LTO option (#1316 )

2019-06-19 12:53:03 -07:00

README.md

Give specular-color the ability to compute f82 (or other angles) (#1443 )

2019-07-26 08:56:24 -10:00

README.md

specular-color

specular-color computes the base color of conductors based on spectral data. The base color is output in linear and sRGB formats. The base color is the reflectance at normal incidence (0°) and is often noted f0.

specular-color can also compute the perceived color of a conductor at another angle, set to ~82° by default. This value is particularly useful when used in combination with the Lazanyi-Schlick model to better approximate the behavior of metallic surfaces at grazing angles. See Hoffman 2019, "Fresnel Equations Considered Harmful".

Usage

$ specular-color <spectral data file>

The spectral data files can be obtained from Refractive Index.

For instance, to compute the base color of gold:

$ specular-color data/gold.txt

To set the second angle, use -a to specify the angle in degrees:

$ specular-color -a 75 data/gold.txt