Original subtitles

The lichens give the wall a lot of character, but we can still push them a bit further.

Currently they have a solid color, without any texture, so let's work on that.

As lichens age, they seem to get darker, and as they grow outwards,

the center of the lichens tends to be darker than the edges, so let's replicate that.

It just so happens, that we already have such a gradient for the lichens,

as their shape is basically being defined as a threshold on a gradient.

So let's duplicate this Map Range, leaving it connected to the same Noise channel.

Then let's make some space here, for a MixRGB node.

Let's take a look at it, and set it to multiply.

In this mode, the second color input essentially works like the Value input in the Hue Saturation

node, but without requiring the extra computations for the hue and saturation.

So let's connect the Map Range to the second color, and set the factor to one,

so that it takes full effect. This makes everything outside the lichens black,

as right now this Map Range is the same as the lichen mask, which is zero outside the lichens.

But now we can tweak the range to get a gradient over the lichens.

If we increase the maximum input, we extend the edge fade farther into the lichens. But now we can

see this sharp edge where the fade ends, so let's set the interpolation to Smooth Step to fix that.

Now let's invert the output range, as we actually want the center to be darker, rather

than the edges. And let's set the darkest color to something like 0.5, rather than completely black.

Then, if we take a look at the combined color output,

we can better visualize how this gradient looks on the lichens.

So let's adjust the ranges a bit, and check how it looks on different lichens.

And let's organize these nodes a bit.

Additionally to the color gradient, lichens also have a complex and detailed texture,

but since we want to keep it simple, as the lichens are just a detail,

it'll be enough to use a generic Noise, just so they don't look completely flat.

So let's duplicate this Noise, and make it a lot finer. Then let's make some space here,

so that we can combine this noise into our darkening factor with a Math node.

Let's set it to multiply, and connect the Noise.

Then, if we take a look, we can see it together with the gradient. And looking at the wall color,

the noise starts making it a bit more organic. But let's make it even a bit finer.

And let's drop a Map Range here, so that we can make it a bit less dark.

Now let's tweak the Noise a bit more. We could use some more roughness.

And perhaps we can reduce the detail a bit, as this amount of detail doesn't even seem

to be visible at this scale, so reducing it just makes the Noise a bit more efficient.

And that's our lichen texture. So let's snap the nodes into place.

And now that we have multiple noises here, let's color code them to keep track of their relative

scales. This is the high frequency noise, so let's copy the yellow color with Ctrl+Shift+C.

And these nodes are all about the low frequency lichen shape, so let's copy the red node color.

And finally, let's look at the shader output,

and see how much more natural the lichens look with this extra gradient and noise.