Understanding what makes a realistic material
For this exercise we’re going to create a wood from a real world example and go over some visual cues that can help you identify material values.
First thing I always do when trying to deconstruct a real-world object is look at the highlights and any reflections on an object. This will tell me 3 things: Reflectivity, R.Glossiness and Fresnel values. I ignore the wood in this case (the Diffuse map) because I want to know how the light is reflecting off the surface. Take away the Diffuse and this could be the start of any other material.
The highlights on this product are reflecting back a light source and telling me this surface is moderately glossy. You can tell because the highlight doesn’t spread far from the brightest point. If you look closer you can see that the highlight isn’t perfectly smooth either so the wood grain, or other surface imperfection, is breaking it up. So we know we’ll need a map in the R.Glossiness too. Another way to tell if something has a high R.Gloss is if any reflections are clearly identifiable in the object. Here we can make out the legs in the reflection on the underside of the seat.
The reflectivity of the surface is basically how much it bounces back the surrounding environment. The higher the value the more mirror like it becomes. This chair appears to be very reflective because we’re able to see the white studio environment reflected back from a lot of angles. If it weren’t as reflective you would see more of the wood material instead. Again, it appears there is something breaking up the reflection as these areas vary from light to dark.