Original subtitles

The wall itself is pretty much done, and at this point we're just adding stuff onto it,

to get all the visual appeal we can. It's always good to break up repetitive

textures by overlaying different patterns, to make it less uniform.

So thinking of things with different shapes and frequencies than the bricks,

which might be found on old walls, lichens come to mind as an interesting possibility.

So let's see how we can approach this. Lichens are incredibly complex,

and we could probably dedicate a whole shader as big as this one just to lichens,

but since our shader is already getting pretty big and heavy, and seeing as the

lichens are not the main subject, let's try to keep it as simple as possible.

Lichens can have all sorts of shapes, so first we'll need a way to generate those. So let's get

a Texture Coordinate node in here, and yet another one of those incredibly versatile Noise Textures.

Then we can add a Map Range node, and push the minimum input way up. This is a cool trick,

to cut off most of a noise, and keep only the very peaks, so that you get little

islands of different shapes, similarly to what we did for the mortar gaps.

Then we can also lower the maximum input to get a sharper edge. We don't want this many lichens,

so let's make the texture a bit bigger so that the distribution is a bit more sparse.

Then, to make them a bit smaller, we can raise the threshold more.

Let's set the Noise to 2D, and tweak the parameters a bit. Right now, the shapes are

looking a bit too smooth, so let's increase the detail, to get more interesting shapes.

Now that we have our mask, let's create some space here,

and add a Mix RGB node to mix in the color of our lichens.

And then we can connect the mask to the factor.

Now if we take a look at the color, we see all these spots.

So let's adjust the color to something more "licheny". For instance a pale green.

But actually, lichens exist in many different colors, so let's get some variation here.

We'll need a distinct texture pattern to drive our color variation,

so let's add a Separate RGB node, to get access to the other texture channels,

and let's connect the Map Range to the R channel, just for consistency.

Then, let's add a color ramp, and connect it to another channel.

This allows us to map different brightness values to different colors.

Let's bring these handles a bit closer, and copy the green color into the first one.

We can also use it as a starting point for the

second one. But let's adjust it to be a more yellow color.

Now if we look at the Color output, we see that a bunch of the lichens became yellow. We can adjust

the proportion of green and yellow lichens, by shifting the handles left or right. The amount

of coverage of each color will be proportional to the amount of space they take on the color ramp.

If we take a look at the output of the color ramp, we see that it creates a similar texture

to the Map Range below, except that the islands are now colored. Note that this

trick for coloring the lichens only works because the texture we're using to feed the color ramp

is distinct from the texture we're feeding the Map Range, otherwise, their respective islands would

map exactly onto each other, and all the lichens would have the same color, in this case yellow.

Let's adjust the ramp a bit, to dial in our desired color distribution.

Now let's take a look at the shader. The lichens are definitely breaking up the uniformity of the

wall, but if we look a bit closer, we see that they are just flat spots on the wall,

as if they were painted on. This is especially obvious in Cycles,

where the displacement just helps to highlight how flat these lichens are.

So to make them a bit more believable, let's raise them off the surface of the bricks a bit.

Since our mask already has a little fade around the edges, it's as simple as just

adding it to the displacement texture. So let's get a Math node in here, and plug in the mask.

Immediately they pop out of the wall, but it's a bit hard to see with this low res displacement,

so let's bump up the subdivisions.

Now it's clear that the displacement is a bit too intense,

so let's add a Math node set to multiply onto the lichen displacement, so that we

can reduce the intensity a bit. We want them to be just ever so slightly raised off the surface,

so let's set the intensity to something like 0.1. Just enough to give them that slight 3D feel.

Note how this helps in Eevee as well, as it causes the slightest outline,

making it feel like they are that little bit raised off the wall.

Now let's frame these nodes, and name them appropriately.

All these nodes are being used to mix in colors of different elements,

so let's frame them as well, and name it Color Components.

Then we can just maximize the node editor with Ctrl+Space,

so that the viewport is not constantly refreshing while we organize the node tree.

Finally, we can give the Lichen Frame an appropriate background color.

Perhaps based on the green we used in the shader itself.

And then just copy it over to the other Lichen Frame, and the corresponding Color Mix node.

And then let's just admire the newly added texture variety in Cycles!