I have a model with a mirror. Its reflection looks like a satin finish. The reason, if you were to zoom in really close and render is that the sky image is very pixelated. No number of passes resolves the reflection any further.
What would I have to tweak to get the reflection mirror-like?
I’m guessing that the ‘sky image’ is one of the default HDRI included with nXt. If so, these images are very low resolution in terms of pixel dimensions. Find a high resolution HDRI and use that instead and you won’t have to decrease the sharpness of the metal material. HDRI can have a low pixel resolution to keep the file size down while still being effective for image based lighting.
Some free options for higher res HDRI…
http://www.food4rhino.com/category/materials/environment
There are many sky HDRIs for purchase out there too of course, look up Dosch Design for instance.