The 3Delight Sky is a utility node that can be used for image based lighting of daylight conditions. It is very well suited as a fast lighting rig. 3Delight can extract sharp shadows using this shader so that no directional light is needed to cast shadows from the sun.
This shader is based on the Hosek-Wilkie sky model. It is an analytical model of the daytime sky that includes the latest improvement in this field of research. This model is able to properly picture sunsets and lighting in high turbidity environments - such as lighting during a moist day.
The Parameters
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Intensity | This drives the overall intensity of the sky. It is a direct multiplier of the sky radiance function.
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Turbidity | This parameter determines the overall aerosol content of the air. As an example, a moist day will have higher turbidity values than a dry day. Values range between 1 and 10.
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Ground Color | Changing ground color affects the brightness of the whole sky-dome, especially in high turbidity settings. High albedo values can occur in winter scenes - snow reflectance is very bright so almost all incident radiation is reflected and backscattered towards the viewer.
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Elevation | This the elevation of the sun.
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Azimuth | This is the azimuth of the sun.
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Sky Tint |
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Sun Tint |
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Sun Size | The size of the sun in the sky, in degrees. The default value (0.51 degrees) is the size of the sun as seen on earth. Note that changing the size of the sun doesn't affect the overall radiance of the sky in this model but the objects will receive more light, as seen in the images below.
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Draw Sun Disk | This enables or disable the sun in the sky. Disabling the sun will disable the drawing of the sharp component of the shadows (the strongly directional shadow | |||
Draw Ground |
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Quick Start
- Open 3Delight's Render Globals
- In Render Elements, make sure that the environment shader is used for the Background Fill
- Create an environment light by clicking on the checker boarding facing Environment Light
- Click on AE to open the environment node in the Attribute Editor
- Click on the checkboard icon to connect our 3Delight Sky shader to the Texture parameter
Start by opening the 3Delight render options: