.. _plugin-bsdf-ocean_mishchenko:

Oceanic reflection model (:monosp:`ocean-mishchenko`)
-----------------------------------------------------

.. pluginparameters::

 * - wind_speed
   - |float|
   - :math:`k \in [0, 37.54]` m/s.
   - Specifies the wind speed at which to evaluate the oceanic reflectance
     (Default: :monosp:`0.1 m/s`).

 * - eta, k
   - |spectrum| or |texture|
   - Real and imaginary components of the water's index of refraction.
     (Default: :monosp:`1.33, 0.`)
   - |exposed|, |differentiable|, |discontinuous|

 * - ext_ior
   - |spectrum| or |texture|
   - Exterior index of refraction specified numerically or using a known
     material name. Note that the complex component is assumed to be 0
     (Default: 1.000277).

 * - shadowing
   - |bool|
   - Indicates whether evaluation accounts for the shadowing-masking term.
     (Default: :monosp:`true`).

This plugin implements the polarized oceanic reflection model originally
implemented by :cite:`Mishchenko1997AerosolRetrievalPolarization`. This model
focuses on the sunglint reflectance, which follows the Cox and Munk surface
slope probability distribution.

Note that this material is one-sided---that is, observed from the
back side, it will be completely black. If this is undesirable,
consider using the ``twosided`` BSDF adapter plugin.
The following snippet describes an oceanic surface material with monochromatic
parameters:

.. tab-set-code::

    .. code-block:: python

        "type": "ocean_mishchenko",
        "wind_speed": 10,
        "eta": 1.33,
        "k": 0.,
        "ext_ior": 1.0,

    .. code-block:: xml

        <bsdf type="ocean_mishchenko">
            <float name="wind_speed" value="10"/>
            <float name="eta" value="1.33"/>
            <float name="k" value="0."/>
            <float name="ext_ior" value=1.0/>
        </bsdf>

.. note:: This model only implements the sunglint reflection. See :ref:`ocean
    legacy <plugin-bsdf-ocean_legacy>` for a bsdf that includes whitecap, sunglint,
    and underlight reflectance.