Render Tips 3: Natural light on Closed Interiors (Neon Glass)

When having natural sunlight entering into a closed space through a translucent material as glass, the use of the Neon Glass shader is critical: the right balance between the intensity value on the neon source and the direct heliodon lighting gives a more realistic outcome.

The Neon Glass shaders is view-independent, so it is defined just as a material shader and behaves the same way on all views. The Neon Glass shader is totally independent of any other light sources and acts as an homogeneous emitting surface that emulates the diffusion of light as it crosses a glass surface.

In the enclosed file called Natural Light Interiors.atl there are 5 perspective views with different sets of values each. To demonstrate the analysis of these scenarios, first we execute a render with Neon Glass Shader set at zero value:

The Neon Glass Shader is to be found in the a Surface folder:

Once applied, you will get the dialog box for the Neon Glass Shader. For most interior scenes, a value between one and two for windows and skylights is more than enough; in other occasions, when a window may be used as a main light source for a scene, selection of a higher value may be more adequate:

For the first perspective we have the Neon Glass Shader as the only source of illumination:

Perspective 1

For the second perspective we combine the Neon Glass Shader with the camera ambient light to compensate the lack of additional sources. The final effect is an overall increase in illumination. This option is only recommended in critical situations where the space is too dark, but excessive use of the camera ambient light may give unnatural results, such as this:

Perspective 2

On the third view we combine Neon Glass with the Heliodon without sky illumination. With this combination the scene becomes more and more real and rich in tones and light sources (note: the camera ambient is deactivated):

Perspective 3

For the last perspective we complement the Neon Glass Shader with direct sunlight and sky illumination. These together give a more realistic final effect and thus our interior scene becomes very rich and complex.

Perspective 4

The right balance between Neon Glass intensity and Heliodon guarantees that the scene has natural feel, the Neon intensity should be use with caution since too much intensity may render overexposed results.

Good luck! We hope this tutorial helps you to achieve better results with Artlantis!

Author: Sergio Rodriguez