Environment and Light Plugins for LightWave 3D


Sunsky

Texture plugin for LightWave3D 8.0 & 9.0+
coded by Denis Pontonnier.
Earlier Mac UB compiles by Michael Wolf.
UB are for Intel and PPC, 32-bit requires at least OSX 10.4, 64-bit at least 10.5 .
Earlier Win64 versions were compiled by Marvin Landis.
Thanks to Paolo Zambrini for suggestions and testing,
Grzegorz Tanski and Michael Wolf for help.
Display Color System presets by Gerardo Estrada.

 

 

-Sunsky is basically a procedural texture for Texture Environment, with more components like lights in the last versions.

-Gets the rotation angles of the selected Light and simulates a daylight sky.

-The Lightwave "Sun Spot" motion modifier can be applied to the light for accurate sun position/rotation
with date/time for a given location (keep default 1 km or more as distance).

-Gets zxY colors from the original sampling method and lets the users select
between 6 color systems to convert to current rgb values, and select different
ways to apply exponential exposure to get viewable colors.

-All sky model has a main "Turbidity" variable parameter,
Nishita model has also Altitude, Hase and Ozone.

-'Preetham sky model has the following five polymonials for alterating this model,"Horizon Brightness",
"Horizon Gradient", "Circumsolar Intensity", "Circumsolar Width, "Backscattered Light".

-Brightness, Constrast, Hue, Saturation and Gamma are available in Correction/Editing tab.

-An attenuated Sun color is evaluated mixing :
Rayleigh scattering,
Aerosol (water + dust) attenuation,
Attenuation due to ozone absorption,
Attenuation due to mixed gases absorption,
Attenuation due to water vapor absorption,
for mapping a disk on the sky background texture,
the sun color is normalized at 100% intensity, but it can be set to higher value for texture.

-Sunsky includes a Suncolor channel modifier plugin for sending and applying the color and intensity
to the R, G and B Color envelope of the sun light.
The Sky Amount is for mixing the solar color with the color of the brightest area of the sky with same correction
than the texture. Since the Sun color is normalized, it is a saturated value, decrease it around 0.5 to get a color
like after exposure.
Intensity channel is also a mix between the the Sun Intensity after HSV exposure and the amount of the brightest
sky value after conversion, exposure and correction,
it is scaled by the sun intensity parameter set in the texture plugin and the
Value parameter in the modifier.

-With "(Inv) Exp. Exposure" set to zero exposure is skipped (x32 version), with full colors and radiosity enabled,
final render need to be re-exposed or tonemapped with a proper gamma (e.g. DP Filter Tonemap and Exposure node).

 

Additions in Sunsky 96 and Sunsky 11:

-Three different sky models, the well-known 'Preetham', the 'Hosek & Wilkie' model,
a significant improvement for better sunset, high atmospheric turbidity and
an "Albedo" ground influence, both sky and sun radiances are modified,
as third choice, the Nishita model (LW11->2020), with various other perturbations.

-Sunsky Environment,
a 'more accessible' alternative to the Sunsky Texture, for sky background
(in LW 2020 visible only through Environment Light or SK Sky Light).

-SK Sun Light,
distant light with soft shadows adjustable with Angle parameter,
interactive with the Environment/Texture background and the SK Sky Light.
Sun Light has its own Sun Editing parameters (HSV), separated from Sky.
can be positionned manually or respecting Time Zone, directly with City Presets,
or with Longitude, latitude and GMT time zone,
Day, Month, Year and animatable Time (Decimal).

-SK Sky Light,
hemispherical sky radiance with soft shadows, interactive with the Environment/Texture background and the SK Sun Light.
with Sky Editing parameters (HSV).

Final Gather compared to Sky Light.

-Sunsky Atmosphere,
a volumetric plugin for adding some colored sun flare in the image.
varying with the sun position and angle of view, Mie scattering, Rayleigh scattering,
Light Inscatter, Light Attenuation (100% no effect),
View Angle Factor (100% full front of sun effect) and Distance Multiplier.
Affects objects and/or background horizon, with Horizon Haze and Max angle.

Sunsky Lights without and with Sunsky Atmosphere.

Sun Light and GI, Sun and Sky Light with GI.

-Sunsky Motion,
correct placement of the SK Sun Light for LW Lens flare.

All of these exterior daylight components can be added with the Add Sunsky command (Lscript).

-SK Portal Light,
interactive with the Environment/Texture background and the SK Sun Light.
same light than Sky Light but can be placed and sized on windows or doors
for more efficient interior lighting and sampling, less noise and smoother shadows.

Presets can be saved for Environment, Texture and Lights, knowing that a major part
of the parameters and options of Sunsky are globals.

The global Sunsky parameters should be adjusted for background environment first,
then the Light Intensity can be used for increasing/decreasing Sunsky lighting
without affecting the other Sunsky components.

 

 

References:
'A Practical Analytic Model for Daylight'
by A. J. Preetham, Peter Shirley and Brian Smits.
'Colour Rendering of Spectra' by John Walker,
RGB conversion modified by Andrew J. S. Hamilton.
'An Analytic Model for Full Spectral Sky-Dome Radiance'
by Lukas Hosek and Alexander Wilkie (see readme file),
'Display Method of the Sky Color Taking into Account Multiple Scattering'
by Tomoyuki Nishita, Yoshinori Dobashi, Kazufumi Kaneda and Hideo Yamashita.

 

 

 

 

For Lightwave 8.5+ no Lights:
Download (Win32)         Sunsky_x32.zip
  (Updated 02/21/12)
Download (Win64)         Sunsky_x64.zip
  (Updated 02/22/12)
Download (Mac UB 32 and 64-bit)       Sunsky_UB.zip
  (Updated 06/15/11)

 

 

For Lightwave 9.6+ with Lights:
Download (Win32)         Sunsky96_x32.zip
  (Updated 05/21/15)
Download (Win64)         Sunsky96_x64.zip
  (Updated 05/21/15)
Download (Mac UB 32 and 64-bit)       Sunsky96_UB.zip
  (Updated 06/23/14)

 

 

For Lightwave 11-2015 with LW Unified Sampling:
Download (Win32)         Sunsky11_x32.zip
  (Updated 01/31/21)
Download (Win64)         Sunsky11_x64.zip
  (Updated 11/21/21)
Download (Mac UB 32 and 64-bit)       Sunsky11_UB.zip
  (Updated 11/21/211)

 

Add Sunsky, Lscript (LW 11->2015):
Add_Sunsky.zip
  (Updated 03/30/12)

 

 

For Lightwave 2018 (->2019):
- (removed Volumetric Atmosphere).
Download (Win64)         Sunsky2018_x64.zip
  (Updated 11/21/21)
Download (Mac UB 64-bit) Sunsky2018_UB.zip
  (Updated 11/21/21)

 

 

For Lightwave 2020:
SK Sky Light should replace the Environment Light,
then check Camera Visibility for viewing Sky Environment Backdrop.
Download (Win64)         Sunsky2020_x64.zip
  (Updated 11/21/21)
Download (Mac UB 64-bit) Sunsky2020_UB.zip
  (Updated 11/21/21)

 

Add Sunsky 2018+, Lscript:
Add_Sunsky_2018.zip
  (Updated 01/31/21)<

 

 

These plugins are freeware but donations are appreciated, thanks.

 

 

 

 

 

 

 

 

 


Copyright © 2021 Denis Pontonnier. Denis.Pontonnier@wanadoo.fr