Unfortunately, the description of function for the Illumination tab of the object editor is splitted and exists at two positions in the DELTAGEN STAGE user guide for 3DEXCITE DELTAGEN MARKETING SUITE R2018x.
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 STAGE, the following four functions are displayed:
- Ambient occlusion
- Emissive object importance sampling
- GI shadow catcher
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.
- uses existing light sources of the scene
- ensures darkening by the shadow texture
- 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.
The GI shadow catcher specifies an object in order to render a Global illumination computed shadow onto a 2D backplate image. Select the desired object that should be set as a shadow catcher and check the option Use object as shadow catcher. As soon as Global illumination is activated, the shadow catcher is used to recreate the shadow.