mental ray Architectural and Design Visualization Shader Library

3.8 Sky- and Environment Portals 77The reason is the high contrast input. FG contains a filter that is intended to avoid a speckledresult if some stray FG rays hit a single extremely bright object, so the filter removes thebrightest rays. But our scene really is high contrast, and we actually expect some rays to bemuch brighter than others.Using FG filter = 0In our case the filter actually is fighting what we are trying to do. We can turn off the filter,as in the image above, which helps our light distribution some, but not the splotches, nor the“disconnect” of the shelves to the wall.Since we are using mia material, we have a built in ambient occlusion to help in exactly thesesituations. However, turning that up only helps partially:Adding AO - helps a bitThe lone solution available in the past was to simply increase the quality of the FG settings.And naturally, we are using very low settings, so the bad quality is not surprising at this stage.Lets turn up the knobs: