6.3.1 General attributes

Iray tab when Iray Interactive is selected
Indirect Light Mode
Sets the approximation method for indirect lighting
Type off
Calculates no indirect lighting except specular transmission and reflection.
Type coarse scale
Calculates diffuse indirect illumination.
The coarse mode is suitable to obtain a fast early impression of the indirect illumination in the scene. At the first primary hit point, the indirect illumination does only contribute to the diffuse layers, which means that glossy contributions are only taken into account at secondary hits and beyond.
fine scale
Calculates indirect illumination, including glossy and measured BRDFs.
In fine scale mode, all reflective layers, including glossy and measured BRDFs, of the material receive indirect illumination. Furthermore, indirect illumination from the close vicinity of the shading location is taken into account more accurately.
Firefly Filter
The FireFly Filter automatically rejects outliers which would lead to displeasing low-frequency contributions which converge away only slowly. This is similar to the FireFly Filter in Iray Photoreal. However, this means that some contributions are cut-off.
Allows shadows to be forcibly turned off
Ibl Falloff
If this flag is enabled, the Falloff min/max Distance parameters in the Ambient Occlusion and Lighting section also affect raytraced occlusion for IBL and instant sun and sky.
Maximum trace depth settings are respected by Iray Interactive. This attribute controls the overall number of trace depth.
Depth Reflect
This value correspond to the maximum total number of bounces and maximum number of reflections.
Depth Refract
This value correspond to the maximum total number of refractions and maximum number of shadow refractions respectively.
Ray Importance Threshold
If the contribution of a specular reflection or refraction bounce falls below this value it is cut off. The lower the value the more accurate the result. The tradeoff is elapsed time. Compared to limiting the trace depth, using this setting usually results in a better performance-quality ratio.