Daylight

 

OctaneRender® has a powerful Daylight environment system to simulate real-world illumination that consists of a primary light (sun), indirect light (sky/environment), and atmosphere. This is the default lighting system that is active when you create a Render Target node.

Figure 1: The Daylight Environment rendering using the default settings

 

The Daylight system is found in the Main tab of the Render Target parameters window (Figure 2).

Environment_Daylight_Fig02_Houdini_v2021.JPG

Figure 2: Accessing the Daylight parameter from the Main tab of a Render Target node

 

Parameters specific to the Daylight system are found in the DL Environment tab in the Render Target's parameters (Figure 3).

Environment_Daylight_Fig03_Houdini_v2021.JPG

Figure 3: The Daylight Environment parameters

 

Daylight (DL) Environment Parameters

Longitude/Latitude

Make realistic sun settings for a specified geographic location.

 

Month/Day/GMT Offset/Hour

Place the sun in the sky according to the date/time for the sun at the current longitude/latitude.

 

Sky Turbidity

The Turbidity can adjust the sharpness of the sun light's shadows. A low value creates sharp shadows like a sunny day, and a higher value diffuses the shadows like a cloudy day.

 

Power

Adjusts the light strength. This affects the image's overall contrast and exposure level.

 

Sun Intensity

The scale factor that is applied to the sun only. Use this to adjust the relative power of the sun compared to the sky.

 

North Offset

Adjusts the scene's North direction. This is useful for architecture visualization to ensure the sun's direction in the scene is accurate.

 

Daylight Model - Specifies the daylight model to use as the current environment.

 

Sky Color/Sunset Color

These settings are used by the daylight model to customize the spectral shade of light. This can affect the scene's overall mood.

 

Sun Size

Controls the sun radius in the Daylight environment.

 

Ground Color

Base color of the ground which is an infinite plane that is only visible in the final rendering. It serves to produce a horizon line for the Daylight system. This allows the user to control the color of the infinite ground plane associated with the Sun Sky systems.

 

Ground Start Angle

The angle (in degrees) below the horizon where the transition to the ground color starts.

 

Ground Blend Angle

The angle over which the sky color transitions to the ground color.

 

Importance Sampling - This toggles the Sky texture's importance sampling, similar to the Texture environment's importance sampling.

 

Medium Radius - Adjusts the medium's scale.

 

Backplate - Generates a cutout rendering where foreground elements are positioned in the scene.

 

Reflections - Generates the Planetary environment in scene object reflections.

 

Refractions - Generates the Planetary environment in scene object refractions.

 

Enable Texture Environment

Activates another tab where you can load an HDRIAn image which presents more than 8 bit per color channel unlike most common image formats. texture map as a Sky texture.

 

Enable Environment Medium

Activates another tab where Medium parameters can produce atmospheric effects.