Well, I am kind of new Corona's user and I usually tweak the materials based on the render I am getting. But if the preview from the Material Editor is accurate that means that after creating a material I only need to tweak the material do look good in the render?
I may be crucified for saying this, but I never relied on the Material's preview to create the material and adjust the maps.
Well, depends ;- )
I tweak the
basics in mat editor, but only real render inside environment will tell me more. The editor preview, while plausible (it's the same engine), has just strange lighting setup with large close area light that's really not very representative of any sort of scene. Actually, some materials, I tweak in multiple render environments to check if it behaves accordingly in all of them (direct/non-direct light, interior/exterior).
The new interactive rendering is fantastic for this.
And to quote someone knowleadgeable about this topic, last year in Venice AD, Bertrand Benoit mentioned he only tweaks materials on exact object he intends to use it. So if he is creating rusty black metal for kitchen stove, he will keep rendering that kitchen stove from different angles to see if it behaves like it should.
I do the same pretty much (I am master of pointless viewport rotating and endless unnecessary test renders).
I hope that answers this :- )