Now we want to add some irregularities to our displacement map, so in the ‘Colour 2' slot of our ‘Displacement' smoke map, we will add a stucco procedural.  The stucco procedural will allow us to place irregular ‘splotches' throughout our map.

Change the size of the Stucco Parameters to between 4.0 and 4.5, with a thickness of 0.05 and a threshold of about 0.6 to 0.7.  Adjust the colours so that Colour #2 is a dark grey.  You may leave Colour #1 as default as we will be adding a map to that slot.

It should produce a similar map, as shown in the screenshot below.(Fig.07)


My scene refers to this map as Map #12 (refer to mapping tree).

In the colour #1 slot of Stucco Map #12, add another ‘Smoke' map.  Change the size to about 20, with 3 iterations and an exponent of 1.
You may as well leave the colours as default. (Fig.08)


This map, funnily enough, is also called map #12 in my scene.  I really should have put more thought into this!
In the 2nd colour slot of Stucco – Map #12, we will add yet another stucco map.  Change the settings to represent the image below, and please note that my scene refers to this map as Map #59. (Fig.09)


Now we will go back to our smoke map (Smoke Map #12), and in the 1st colour slot we will add another smoke map (referring to Map #1 – Smoke).

Let's adjust this smoke map as per the screenshot below. (Fig.10)



In Smoke Map #1 (Our latest smoke map), we will add another stucco map (Stucco Map #1).  Please see below.(Fig.11)


And finally, in the colour #2 slot of our Stucco Map #1, we will add a Cellular map, which my scene refers to as Cellular Map #56.

Adjust to match the settings in the picture below.(Fig.12)

Step 3: Fine-tuning the Procedural Map

We have now compiled our 100% procedural displacement map.  Let's see how it looks! (Fig.13)


It still isn't quite what we're after, is it?  This is due, primarily, to our scene's scale and the scale of the maps we have created (I did mention this tutorial requires extensive test rendering, didn't I?).

Let's make some of the map sizes smaller, especially our ‘Displacement' smoke map.  I reduced the size from 6 to 3 in the ‘displacement' smoke map only, and you can see how dramatic the difference is with the displacement effect. This looks a lot better.(Fig.14)