What is the CoronaBumpConverter map?
By default, 3ds Max treats bump maps differently than "regular" RGB maps, so some maps do not work correctly as inputs to bump mapping. The Corona Bump Converter resolves this, allowing you to use any map as an input to the bump map channel in a shader.
It also lets you use the 3ds Max native Output settings to apply adjustments to your bump map and get the results you would expect, which is not possible in case of plugging a map directly into a material's bump slot.
Note: the CoronaBumpConverter relies on UVW mapping, so if an object does not use UVW maps, or if they are incorrect, it may produce artifacts, or may not work at all.
Object with noise map used as bump map. Default settings. No BumpConverter used.
Object with noise map used as bump map. No BumpConverter used. The output parameters of the noise map have been updated, however the rendered image looks exactly the same as with the default settings.
Object with noise map used as bump map. BumpConverter used. The output parameters of the noise map have been updated, and this is correctly reflected in the rendered image.