Octane Standalone Documentation

The Texture Environment affects the environment's illumination and color. This node can add an HDRI environment texture to the scene for illumination. It can be accessed it by right-clicking in the Node Graph Editor, navigating to the Environments category, and then choosing Texture Environment (figure 1).

Figure 1: Selecting the Texture environment in the Node Graph Editor

The Texture color swatch can scale from white to black as a uniform color for scene illumination or a color can be selected since the default is an RGB Color node (figure 2).

Figure 2: Texture is used to shade the background illumination

A High Dynamic Range Image (HDRI) map can be used as a texture environment. To use an HDRI file as the environment, connect an RGB Image node to the Texture Environment node's Texture pin (figure 3).

Figure 3: Loading an RGB image as the texture

Texture Environment Parameters

Texture - Specifies either a color using the RGB Color node or an HDR image using the RGB Image node. 

Power - Changes the HDR image's brightness.

Importance Sampling - Enables quicker convergence (noise reduction) for HRDI images by applying importance to certain areas of the HDRI, which prioritizes areas to resolve sample rays more often than other areas.

Visibility Cache - Enables adaptive environment light sampling that takes visibility into account.

Cast Photons - If photon mapping is used, this will cast photons from bright areas in the environment map.

Medium - This parameter accepts an Absorption, Scattering, or Volume medium node to create volume/fog effects across the scene. For more information, see the Volume Fog Effects topic under the Effects category in this manual.

Medium Radius - Adjusts the medium's scale.

Medium Light Pass mask - Enables or disables lights on the scattering environment medium.

Trace Sets 

The Trace Set system allows for greater control over including or excluding scene data from object surfaces when light hits the surface.

Visible Environment

Nodes connected to the Environment pin on a Render Target node are considered the primary environment. Nodes connected to the Visible Environment pin on a Render Target node provide a way to separate the background, reflections and refractions from the primary environment. Both the Environment and the Visible Environment pins accept Daylight, Planetary, and Texture environment nodes. 

Backplate - Uses the environment specified in the Visible Environment node as the background.

Reflections - Uses the environment specified in the Visible Environment node as the scene object reflections.

Refractions - Uses the environment specified in the Visible Environment node as the scene object refractions.

In some cases, shadows cast when using an HDR image in the Texture Environment node turn out too soft. In these situations, combine the HDR image with the Daylight Environment node instead of using the Texture Environment (Figure 4). Figure 5 shows a comparison between using the Texture Environment to light a scene and using Daylight Environment with an HDR image as the Sky texture.

Figure 4: Adding an HDRI to the Sky Texture in a Daylight Environment node

Figure 5: Comparison of shadow quality between Texture Environment only (left) and Daylight Environment with a sky texture (right)