Indigo Manual > Indigo for 3ds Max

Environment settings

The Indigo environment settings can be set from the normal 3ds Max environment settings, allowing a choice of physically-based Sun/sky or environment map illumination in your scene.

For example, to create a Sun/sky environment, open the Environment Settings dialog (keyboard shortcut: 8) and select the Indigo SunSky option from the Indigo Renderer Maps list:

Setting a Sun/sky background map

The Indigo Sun/sky and environment map settings are described in the following sections.

Physically-based Sun/sky

Indigo offers two Sun/sky models: either the classical Preetham Shirley Smits model, or the more accurate spectrally simulated model.

Indigo Sun/sky map settings

  • Sky model - Selects the sun and sky model to use; the "classic" model is a standard physically-based sun and sky model, and the captured simulation is the directly simulated sun and sky introduced in Indigo 3.2.
  • Sun node - Sets the light source which will act as the sun. This must be specified in order for the sun and sky model to work.
  • Sun layer - The light layer index in which the direct sunlight contribution is stored.
  • Sky layer - The light layer index in which the skylight contribution is stored.
  • Turbidity - A higher turbidity corresponds to more overcast skies. Currently only affects the original sky model.

Image environment map

In this mode, an Indigo Texture (potentially in HDR) can be used as a background map to illuminate the scene. Usually latitude / longitude maps are saved in the compact .EXR format.

Indigo Environment map settings

  • Color - A constant background colour in the given emission units.
  • Image - Allows you to specify an Indigo Texture map as an image source. For more information on setting up HDR environment maps, please see the subsection on using image environment maps.
  • Intensity - A linear brightness scale factor.
  • Exposure - An exponential brightness scale factor.
  • Base emission - Allows you to specify a given spectrum map as the basic illumination component, e.g. 6500K blackbody for "white". The Image and Color scale with this base spectral colour.
Indigo Manual > Indigo for 3ds Max > Environment settings

Using image environment maps

In this section we'll cover using environment maps to illuminate a scene.

In a simple scene with the background clearly visible, open the Environment settings (keyboard shortcut: 8 key) and add a new Indigo Environment map:

Selecting an Indigo Environment map

In the Indigo Environment map settings, create a new Indigo Texture map for the Image channel:

Adding an Indigo Texture map to the Environment map

In the Indigo Texture map settings, the coordinates used should be set to "Environment (lat / long)" if you are using a normal HDR environment map:

Selecting the coordinate use for the Indigo Texture map

This is for the usual latitude / longitude format environment maps, which look like this (example by Paul Debevec):

Example lat/long env map, by Paul Debevec

If we render this setup with a simple "teapot on a pedestal" scene, we get the following result:

Teapot on a pedestal