In WIP rel6.0.17283.9031, 2017/10/10
The preview seems washed out and won’t update.
Tried update preview now, also turned on auto-update.
Maybe I did adjusted something in advanced setting?
Also going through the properties, there’s couple of duplicate items
such as RhinoCycles.TileX vs RhinoCycles.tilex
Is there difference in those?
To get rid of the duplicates you can use TestCleanupRhinoCyclesSettings. You may want to check in Tools > Options > Cycles that diffuse bounces is set to 0 (default).
After testing this myself a bit more the best thing to do is to go into the thumbnail properties and set background to checkered, then save as default.
I think the preview scene is set up so that the background color/texture is used for lighting. For pure white it means also a bright all-around light. The default studio environment seems to be very powerful. Skylighting was recently fixed such that white becomes actually white, values aren’t scaled down anymore. I’ll have to mention this to @andy so we can look into improving the preview scene.
edit: I would otherwise suggest changing the environment for previews, but that seems to be broken currently: RH-41990
