Hosek-Wilkie environment

Description

../../../_images/hosek.jpg

Scene lit by a Hosek-Wilkie environment

Environment The Hosek-Wilkie environment simulates sun and the atmosphere lighting of the earth’s surface. It is based on the work The Sky Dome Appearance Project.

The zenith direction (or normal to the horizon plane) may be set to any value in scene coordinates.

The sun position can be adjusted to any direction in the sky. The turbidity parameter controls the amount of scattering due to mist and dust. It can be set to any value between 2 and 6.

The parameter sunscale scales the sun diameter, without changing its total irradiance. This may improve simulation times in some complex cases. It should be left to 1.0 for realistic results.

Children Nodes

Spectrum albedo The ground albedo spectrum

Parameters

name type description
sunpos vec3 The sun direction
turbidity real The turbidity, or haziness, of the atmosphere. Must be between 1 and 10
zenith vec3 Zenith direction, allows for instance switching between Z-top and Y-top conventions
sunscale real Scaling factor for the sun disc for faster simulations. Does not change direct solar irradiance

Ocean XML 5.0 example

<environment type="hosek" name="environment">
   <prm sunpos="-0.4629      -0.8201 0.3365"/>
   <prm turbidity="2"/>
   <prm zenith="0 0 1"/>
   <prm sunscale="1.0"/>
   <spectrum type="uniform" name="albedo" value="0.5"/>
</environment>