There are dozens of articles over the Internet on how to render photo-realistic images. But most of these look somewhat like this: “How to render realistic images in <Name of the software>“.
This makes the article confined to only one engine (Cycles in case of Blender). So, this made me think, aren’t there some universal rules which can be applied to any form of art?
That’s it. From that point I starting thinking and after a lot of brainstorm and re-brainstorm, I figured out these 7 ways.
At the end of the article there’s a simple formula that I use while making any material in Blender… but the theory should work for any kind of art.
SO, HERE WE GO:
Being one of the broadest and most controversial classifications of the CG industry it is difficult to define an object to be organic or inorganic.
Organic objects are those which are of living origin and all others are inorganic. That’s the simplest way to put it but it has a lot of things going on besides this simple definition.
Inorganic objects have more or less flat surfaces with sharp edges. Though it’s not completely true but mostly they are of non-living origin.
Reflections play a major role especially in the 3d field.
By reflections, I mean those sharp reflections which give us an idea of the environment and the surface material. Every object in the universe reflects light to some extent. In blender too, all objects reflect light but when the roughness comes to around 0.2 (Glossy BSDF) or below, the scene starts breathing and a sense of realism develops. This can be further enhanced using:
It defines which part of the surface of the mesh is glossy and which part is diffuse (or the shader with which it’s mixed).
It defines which parts are rough and which parts are smooth.
Layer Weight and Fresnel
They tell cycles the angle at which the reflection is the most prominent. Layer weight has a factor which can be used to enter values between 0 and 1 instead of directly entering the exact IOR value as seen in Fresnel node.
The place, which you want the object to be in, matters much.
Also, what Kind of dirt, the amount of rust, worn-outs etc. will vary with the place where the object is placed. So, no matter what material you are making, you
Apart from the location, the age of the object or the time for which it has existed matters a lot.
It should be quite easy to understand as we know that the longer a thing is kept motionless at a place, the more amounts of dust and dirt it accumulates. So, the same iron/copper material would look entirely different if they have different age. A newly prepared copper wire and an old, isolated copper pipe will have a completely different feel to them.
I still feel sorry for myself thinking why I didn’t start implementing this concept earlier. Most often we skip this part just being lazy. But I guarantee, using ‘real world’ sizes will not only help you pull off the right reflections, refraction and other aspect of lighting but also it will help you keep everything in your scene in the right proportions.
Heading back to the apples, it can be used to explain the size formula as well. Most probably if you have used the SSS (Subsurface Scattering) shader node in blender then you must have come across the scale value. This is actually the size of the object to give it the most accurate SSS effect. SO, the size of the apple matters to get the right results with the scale value.
6. Lighting context and Camera Position
The type of lighting environment is a key factor which determines which features of the material will be most prominent. For example, to achieve photo-realistic translucency (in a leaf as an example) there has to be a back-light and the camera must be in a straight line with the leaf and the back-light source. Again, in case of reflective surface with Fresnel reflections, there has to be a rim light to apply the Fresnel effect.
A more in-depth example, a human face – you cannot light it up from all directions. It must have a main light source and other minor lights to balance it. (A 3-point lighting system should work well). This will help you to get the most out of the subsurface scattering effect.
Thus, a clever lighting context with an effectively positioned camera can convert your render from a mere render to a photo!
7. That Extra Touch 😉
It is rare to find a brick wall (especially during the rainy season) without any moss or water on it. So why does the CG wall not have such details? Most often no single material exists all alone in the real world. So go ahead and add in those extra touches of realism.
8. How to Approach Creation of a Material in Blender
What I have found in my 30 months experience is starting from the bigger details to the smaller minute details is the most fluid and effective way to approach materials (Also true for any CG software).
With this I conclude this