DELTAGEN HUB: Overview of the Illumination Tab in the Object Editor

 

Solution

As simplification for an easier understanding, use this article as an addendum to the chapter Object Editor in the user guide to get an overview of the entire description of function for the Illumination tab.

In case a shell is selected in the scene, the Illumination tab of the object editor displays several settings to generate real-time shadows or to assign offline shadows (shadow textures or precalculated shadows). For DELTAGEN HUB, the following three functions are displayed:

• Ambient occlusion
• RealLight
• Emissive object importance sampling

Ambient occlusion is an effective technique for real-time scenes. To generate Ambient occlusion, voxels are utilized.  It is only available for opaque geometries. Transparent objects do not receive Ambient occlusion. Furthermore, no objects in distance will be computed.

RealLight is a function for creating and displaying shadow textures. As long as no shadow texture is assigned to the selected object, the option None is selected automatically. If Interactive shadow is selected, shadow textures will be enabled for the selected object. By selected Shadow texture, a desired file of a generated shadow texture can be specified.  For the computation of the shadow texture either choose Occlusion or Lightmap as computation method.

Occlusion:

• uses existing light sources of the scene
• ensures darkening by the shadow texture

Lightmap:

• computes the incidence of light on the object
• uses the texture as a light map for distributing the brightness

The setting Emissive object importance sampling is only enabled for objects with an emissive material type having an emissive value greater than 1. Geometries with an emissive material type applied can be operated as a direct ligth source (mesh light). In case of various  emissive objects in one scene, it is possible to set a scene importance to the individual emissive objects to improve the sampling performance. Handle this importance by adjusting the corresponding factor  individually for each emissive object in the Illumination tab.