caisson posted at 4:12PM Tue, 18 May 2021 - #4419457

The single biggest thing that made Superfly easier for me to understand was realising that Specular has a completely different meaning -

• in Firefly, Specular is a hack to provide fake reflections (to use raytraced reflections in Firefly you would have to add a Reflect node to the material)

• but in Superfly, as everything has real raytraced reflections all the time, Specular means Base Reflectance.

This is why Firefly is often claimed to be faster. It isn’t, it’s just doing a lot less work. If you add Reflect nodes to every material to compare directly with Superfly you will find that speed difference …. quite different. For kicks, try adding some strong DoF too. Like for like, Superfly is way faster.

The second thing that helped me was a basic understanding of the PBR Metal/Rough workflow. Like, the difference between metal and not-metal. Base reflectance vs fresnel. What roughness means.

For me, it's that it is easy observable in the real world.

• A metal is something that is an electric conductor. And you always work with the outermost layer. So a painted metal pipe for instance is not metal as there is paint.

• Roughness is easy understood, if one looks at it, like how "dirty"/beaten or uneven an objects surface is. A mirror have 0 roughness so its reflection is very high. A piece of wood have a high roughness and therefore doesn't reflect like a mirror.

So its pretty easy to take any object look at it and describe it based on these two values.

• The diffuse color is simply the color of the object, nothing else.

• Normal map is just a 3d bump map that is autogenerated. (No one makes these by hand, that would be insane), so as you said a grayscale bump map can do if needed.

Whereas if you work with fake materials and have to replicate an object, its a lot harder to describe it and even harder to put together all the nodes.