00:00 Hey, everybody. Maarten from QuadSpinner
here.
00:02 And today we're going to be discussing
the Erosion2.
00:04 Node Erosion
2 is the node that covers hydraulic
00:08 and to a point of thermal erosion
in Gaea 2
00:11 hydraulic erosion
is the erosion caused by precipitation
00:15 aka rain and snow, which turns into water
flowing down a terrain.
00:19 Thermal erosion is the contracting
and expanding of sediments
00:23 due to temperature
shifting from cold to hot
00:26 hydraulic erosion cuts into a terrain,
causing gullies and valleys, while thermal
00:31 erosion chips away at a terrain, causing
slanted slopes and talus flows.
00:36 I think a lot of you are very keen
to learn more about this node,
00:38 because sometimes
it can feel hard to control,
00:42 It can deliver such varied results
that small changes have a big impact.
00:46 Unlike the old mode
Erosion1, on that node.
00:49 Something important to remember is
that Erosion2 is a completely new node,
00:53 and when you work with it,
00:54 you should avoid thinking of it
as something similar to Erosion1.
00:58 So today we're going to be discussing
the node in depth with every control.
01:02 And I'll show you guys
a few use cases in the form of this
01:06 Scottish Highland terrain and this,
interesting snowy peak.
01:11 I'll just show how Erosion2
can give you these very,
01:14 very different shapes, even when you're
using the same underlying primitive.
01:19 So let's get into the settings.
01:20 This will be the bedrock for our duration.
01:22 And Downcutting showcase.
01:24 So Duration is of course the duration
of the simulation in Erosion2.
01:29 It's very cool because you can even see
how the erosion slowly creeps up.
01:34 So you can imagine this is like
a coastline that is slowly eroding.
01:38 And you can really see how it slowly chips
away at the whole terrain
01:42 Downcutting quite easy.
01:43 It's the strength
at which the erosion cuts down
01:46 into your, terrain,
how deep the gullies are.
01:50 If we lowered this, we'll see that
the gullies become a lot less steep.
01:54 They will, of course, slowly become deeper
as we increase the duration.
01:59 However, depending on how quickly
the actual
02:02 slope tapers off,
they won't reach a certain depth.
02:06 We turn them up really big.
02:08 You can see here right now
that the actual terrain just gets
02:11 totally eroded very aggressively,
right in the beginning,
02:14 and then it kind of tapers off.
02:16 Next up,
02:16 we have a very interesting setting
that maybe not enough people know about.
02:20 It's the Erosion Scale Setting.
02:22 Erosion Scale determines the largest
gully size across the entire terrain.
02:26 So when we have the Erosion Scale
set to a thousand,
02:29 the gullies will be, certain size.
02:32 So as we can see here,
02:34 and when we turn it down to 500,
you'll see that they have
02:36 actually scaled down quite a bit,
drastically changing our terrain,
02:40 keeping the actual base shape
of the terrain a lot more, noticeable.
02:44 And, yeah, we,
see that the terrain is either
02:48 larger scale
and we're just seeing more gullies
02:51 because of the actual distance
that we're looking at the terrain from.
02:54 Or it's just micro,
more micro detail on this certain terrain.
02:57 You can go even further down to 250.
03:01 We'll see a lot more.
03:02 And we can just keep scaling this down
until we get very cool results.
03:07 Erosion Scale basically determines
03:09 the size of the gullies
that the hydraulic erosion causes,
03:12 and it can give you very different
and very interesting results.
03:16 And I would definitely use
multiple erosions with different Erosion
03:19 Scale for different, you know, gully
sizes, one for the big valleys
03:23 and one for the small little creeks,
in a sense, coming down the mountain.
03:27 Yeah.
03:28 Super interesting.
03:29 And let's move on to the sediment.
03:31 So this will be the bedrock layer
for the sediment.
03:34 The Sediment Discharge
settings are probably
03:35 the things that most people know least
about and want to know more of.
03:39 So let's get started with Suspended Load.
03:43 Suspended Load are the lightest sediments
and move very quickly, meaning
03:46 they don't settle quickly and often
03:47 will run to the end of the terrain
when the slope allows.
03:50 These can greatly affect
the shape of the terrain, and as such are
03:53 often turned on at maximum by default.
03:57 So when we look at the Suspended Load,
it's pretty much the gullies.
04:01 It is the actual erosion
04:02 that's happening on to our bedrock here
and cutting away at it.
04:07 When I turn this way down,
04:09 you'll see that the gullies become a lot
less deep and there's less of them.
04:13 The Discharge Angle is the angle
at which it starts.
04:16 So right now, at an angle
04:17 above 24 degrees, the actual erosion
will start cutting away at our terrain.
04:22 And if we lower this, you'll see that
the actual gullies become a lot
04:26 more intense because more of its terrain
is actually being eroded.
04:31 So yeah, you'll see a lot more of these
gullies even form on these flatter areas
04:34 of the terrain.
04:36 And that is just, the Discharge
Angle working.
04:39 We turn it up, the Suspended
Load become less extreme turn this on.
04:44 And there you go.
04:45 Next Bed Load, Bed Load.
04:47 Are the slightly less mobile,
but still quite pervasive sediments.
04:50 It creates sediments easily.
04:52 But these sediments only travel
moderately.
04:54 Increasing this sedimentation can help
larger talus flows and other deposits form
04:59 However, it should be used with care
as it can become quite overpowering.
05:04 It's not necessarily overpowering
on this specific example, however, into
05:07 individual like mountain ranges or such,
it could be quite a lot happening.
05:14 So when we look at this right here,
you can instantly
05:16 see the Bed Load at work,
causing these flows.
05:19 And you can also see that
it flows all the way down the mountain.
05:21 So even at a higher Discharge
Angle here, of 37, where it really sticks
05:26 to these higher angles,
it will still flow all the way down,
05:30 lower angles, you'll see that
the actual flows only start way down
05:34 here, and the gullies are still very
much empty at higher angles.
05:39 And you can see it
05:40 here creeping up a bit,
creating that talus.
05:43 However, there is another sediment
that is even less mobile
05:47 the Coarse Sediments,
05:48 The Coarse Sediments represent loose soil,
rocks, boulders and other loose material
05:53 on the terrain that can create impressive
scree, talus and alluvial facts.
05:57 These sediments
05:58 settle quickly and as such create
very distinctive sedimentation patterns,
06:02 so this sediment is probably the easiest
to recognize when you're working with it,
06:07 because you can really see it move
across your terrain, very noticeably. So.
06:11 If you have a cliff, often
you'll see these rocks that fall down,
06:15 but they don't really flow down
the whole mountain or into the actual
06:19 like gullies
that the hydraulic erosion is creating.
06:22 Often this Coarse Sediment is a bit
more of a thermal erosion effect,
06:27 where just rocks are getting chipped away
from cliffs and they fall down.
06:31 They might roll down a few meters,
but they don't necessarily flow down
06:34 the whole mountain, creating really cool
talus, flows basically.
06:39 The cool thing about this sedimentation
is that we can really follow it
06:42 on its way up.
06:43 So if I just slowly move this upwards,
you'll see that it's slowly
06:46 starts creeping up.
06:47 However it stops, unlike Bed Load
which keeps moving, you'll see that
06:52 the actual gullies from Suspended Load
are visible again after a certain angle.
06:58 As this actual Coarse Sediments
starts moving up the actual cliffs ups,
07:03 the gullies from the Suspended Load
are becoming visible again at the bottom.
07:08 This is in opposition
to the actual Bed Load,
07:11 which keeps flowing and fills up
the gullies even at the bottom.
07:14 Even when it stays up
here, it fills everything up.
07:18 Yeah.
07:19 Altogether they can give you quite
an impressive sedimentation
07:23 on your mountain.
07:25 Something to note here
is that the strength of all of these
07:29 is not individually controlled.
07:31 So when I turn up the strength
for all of them,
07:34 it doesn't mean that
they're all at 0.5 strength.
07:36 They're actually all at one
third strength.
07:38 So if I turn them all up to one right now,
every single one is working
07:43 at one third of its strength
instead of all at 100.
07:46 It's because they're basically
all working in tandem.
07:49 The team is working on a setting
where you can increase the amount of,
07:53 sedimentation volume without the actual
erosion being affected at all.
07:57 So it's
07:58 kind of like artificially increasing
or multiplying the amount of sedimentation
08:02 that you're getting without it
necessarily being realistic.
08:07 So this will be the
08:08 next terrain we're going to be eroding
with these shape controls.
08:12 So Shape controls are basically the
thermal controls that Erosion2 offers.
08:18 Basically these thermal erosion
that you'll see.
08:20 And it really helps blend or tie in
the hydraulic erosion in a lot of cases.
08:26 You can also really strengthen these
controls and get really unique shapes.
08:30 Yeah, I won't be going in too deep
about every single slider
08:33 because they're very connected
to the actual settings up here.
08:37 All you need to know is that
this will be basically the strength
08:40 in general of this control,
so we can turn it up more and more.
08:44 The sharpness will also sort of control
the strength of the thermal,
08:48 but more of these shape strength.
08:49 So the higher return
is the more triangular
08:53 and slanted the actual shape will become.
08:56 The Shape Detail Scale
basically controls the amount of detail
08:59 of the underlying layer
that we still see, right here.
09:03 So if I turn it all the way down,
09:05 you'll see that
we're going to get very sharp shapes.
09:08 But, all the actual shapes from this
underlying layer are kind of disappearing.
09:13 There is some artifacting, but actually this
artifacting can become really cool
09:17 because you can create these cool
cliff faces.
09:20 So now we're going to go to the Orographic
Influence.
09:23 The first thing we're gonna cover
09:24 is the Directional Precipitation,
which is basically be rain shadow effect.
09:29 Rain shadow being rain being blocked
by one side of the mountain range.
09:33 So it rains on one side, and then on
the other side there's not much rain
09:38 because it all fell on one side
due to the actual mountain blocking it.
09:42 Creating this cool effect
where one side of the mountain is
09:45 basically eroded very heavily,
or at least has some erosion on it.
09:49 And the other side of the mountain
is not eroded at all or a little bit.
09:55 This Radial Gradient shows
it very extremely.
09:58 However, with an actual mountain terrain,
it will be less extreme.
10:03 And with the actual
10:03 Rain Shadow effect here
we can control the harshness of the fall
10:07 off in a sense, and the Direction,
of course changes the direction.
10:12 Now we're going to go to the,
10:15 the actual masking controls here.
10:16 You can even plug in your own custom mask,
but right now I'll be using
10:20 the controls inside of the node,
which is the Precipitation controls here.
10:25 So I can basically say
10:27 where precipitation on
the mountain will fall and where it won't.
10:30 So right now
I'm saying that it won't fall on a slope
10:33 steeper than 45 degrees, and it won't fall
above an Altitude of 0.75.
10:38 So basically the top quarter of our
mountain is not receiving any rainfall.
10:43 And it shows,
10:46 we're still getting the thermal erosion
like thermal effects here, but we're not
10:49 getting any of the hydraulic erosion
causing these flows running down.
10:54 I can reverse it.
10:55 And we'll see a lot of these flows
on the top of my mountain
10:59 and not at the bottom, really.
11:01 However, you'll think,
11:02 why is there still flows down here
if it shouldn't, you know, be on mask it out.
11:06 Well, the difference is,
11:07 is that once the actual rain has fallen,
it has to flow down the mountain.
11:11 This is not like Erosion1 
where you could plug in a mask
11:14 and basically turn off the erosion
strength.
11:17 This is pretty much
only controlling the precipitation.
11:20 So the rainfall, snowfall, any way
liquid gets on a terrain, pretty much. So,
11:27 yeah.
11:28 Once liquid hits the top of the mountain,
it's going to flow down.
11:31 So your flows are still going to go down
all the way.
11:34 Basically, what this is,
11:35 what this is just controlling
is that there is no rainfall down here.
11:38 So no
new flows are being created down here.
11:42 Which of course you'll see happening here
in case I reverse it.
11:47 Yeah.
11:47 Pretty much
that's the Orographic Influence.
11:50 You can see how much of a change that is.
11:53 This is kind of an interesting point
right here because as we see
11:57 the erosion settings are very,
very strong.
12:01 You can get so many different effects
with a single node.
12:05 The tiniest change will actually affect
your mountain quite a lot.
12:08 Now how can we change certain things
12:11 like adding sediment to this mountain
without changing this shape?
12:15 You know, like imagine I'm really locked
into this shape and I want to keep it.
12:20 However, I don't want to have any changes
when I turn up the Bed Load,
12:24 which I might get, you know.
12:28 Well, in that
12:28 case, it is just advised to just use
another Erosion node,
12:32 setting the Blend mode to Max,
and then we can just turn down the Down
12:36 cutting,
turn up the Bed Load, turn up the Angle.
12:40 And now we have very amazing control here
over the actual sediment flow.
12:45 I would recommend
using the same Erosion Scale.
12:50 This way you make sure
that the actual sediment build up
12:53 is really going into every gully, as the
actual scale of the gullies is the same.
12:58 It's not 100% necessary,
but it's just something I advise.
13:02 So now that we've actually covered
all these sliders and all the ways
13:05 we can use Erosion2, I have these cool
examples that I made for you guys,
13:10 which are two very different terrains
from the same primitive,
13:15 showing how erosion in different
13:17 settings
can give you totally different results.
13:21 So we have this cool highland terrain.
13:23 Hopefully it's cool, that I created for
you guys and a very snowy peak
13:28 with a very heavily, thermally eroded
look to it.
13:34 Yeah.
13:34 I mean, personally, I love the shapes
and I love how different they are,
13:38 and I love how Erosion2 
can give me these results
13:42 from using it in different ways.
13:46 So let's start with the actual snowy
peaks.
13:48 Why not?
13:49 We'll start right away by creating
this shape that is almost 90% of the work.
13:54 You'll notice that the actual terrain here
is very heavily thermally eroded
13:58 and that is the Shape controls right here
really putting in the work.
14:03 So I had a Duration of 25.
14:04 We're getting quite strong erosion Down
cutting at 0.1.
14:08 So not 0.25.
14:09 So we're actually avoiding it
going too deep into the terrain.
14:13 The Suspended Load is the default settings
except for the Discharge Angle at 15.
14:18 This just made my gullies
a bit wider as the actual erosion
14:22 started happening a bit earlier up
eroding a bit more of the sediment away.
14:27 Bed Load very low point one
just to create this kind of base.
14:31 Oh, just to create this kind of base
14:33 flow here at the bottom,
no Coarse Sediments.
14:36 As I didn't feel like
I needed to put any big
14:39 talus screens on the cliffs here
because it will be covered up by snow.
14:44 The Shape control.
14:45 So point six,
very high, shape control like effect here.
14:49 Shape Sharpness,
which is basically just the.
14:51 Yeah, the sharpness of the actual thermal,
14:55 shape.
14:55 So as you can see, this ridge,
you know, like these very sharp,
14:59 triangular shape, Shape Sharpness kind of
does that for you.
15:05 Shape Detail Scale.
15:06 This will kind of be the amount of details
that are coming from the primitive
15:10 over to the actual,
15:12 eroded terrain here.
15:14 So you'll see it's 0.05,
which is very low.
15:16 The base value is 0.25.
15:19 And you'll notice here
that like these kind of like
15:22 almost cliff stratified little areas
15:24 are very hardly noticeable at this point
because they've just been
15:29 kind of lured 
into the terrain in a sense,
15:32 they've kind of been melted into the terrain,
if I turn this way up, then you'll see
15:35 that the actual, stratification here
will be way more noticeable.
15:39 And a lot more of these details on
the terrain would be noticeable.
15:42 A cool effect
that you'll kind of find here is that the,
15:47 if you work with
15:48 the lower Shape Detail Scale
and a higher Shape Sharpness
15:52 and of course, in general, just a higher
amount of this thermal control,
15:56 you'll start seeing these cool cliffs form
almost naturally.
16:00 It's very interesting how this happens.
16:02 It really shows the Erosion2 node
working
16:06 at its full magic, where it just starts
kind of creating these
16:10 very good looking cliffs
in this very high peak terrain 
16:15 and yeah, they just they work perfectly.
16:17 Now, when you're working with these higher
shape controls here, I find that
16:20 the actual differences between resolution
start becoming bit more noticeable
16:25 because the actual controls are so strong
at this point that the slightest change
16:28 in the simulation
will just have a totally different, look,
16:32 because the actual thermal erosion
on top of it is also changing all terrain.
16:36 So if you like this kind of look right
here, I would say bake this node down
16:41 if you want to.
16:42 And then we can actually
work on detailing, which we'll do now.
16:47 What I'm
doing first is using Transform 3D.
16:49 Drop to Floor
and then scaling it up by 1.35,
16:52 because I don't need all this flat,
dead space around my mountain.
16:56 So I'm just going to move up the actual
terrain or scale up the actual terrain.
16:60 And I'm just going to get a Slope
mask right here and start warping.
17:03 As you know, for my Snowy Peaks video,
I love putting this iterations to four,
17:08 and I put the Roughness of 0.6,
so we get a bit more of a cool,
17:12 high detail Warp right
there, just warping those cliffs.
17:16 So we get some cool rock detail,
17:20 add another Warp, set to Max,
and just add a Height Mask there.
17:24 So we just get some extra rocky
bits right in this area.
17:30 And then we're going to get another slope
17:32 mask and run a Thermal2, Thermal
2 for the snow.
17:36 We're not necessarily using this for
our terrain, but the actual snow field.
17:40 That we'll throw on top this Thermal
2 kind of create this cool, snowy,
17:45 erosion that we'll see here.
17:48 And then of course,
17:50 masking out the Area
mask here to maintain our cliffs detail
17:54 and then adding a Snow field
with six Cascades
17:57 and all kinds of settings to make sure
these snow sticks on top of the terrain.
18:02 I would definitely play around with this
at a lower resolution
18:05 when we use this Snowfield,
because these six Cascades,
18:08 will take a time to,
take its time to actually build itself up.
18:12 But the end results are so amazing.
18:14 This Snowfield node
has such a better fall off
18:17 for the actual snow
compared to the old snow node,
18:21 so I definitely will be using this one
in the future for my snow,
18:26 a Chokepoint and the texturing.
18:29 So just a TextureBase
SatMap, Weathering a file
18:33 I use a Quixel rock
texture here, change the color a bit
18:37 and I create a height selection here
and just mix between the two.
18:42 So if I underlay this here,
18:46 there you go.
18:47 I will just blend this SatMap
so lightly at the bottom here.
18:50 Could be more
maybe something like point five.
18:54 There you go.
18:56 I love using the actual textures
when it comes to mountains like this,
18:59 because for some reason
SatMaps are great, but
19:03 you don't get the same detail
that a texture will give you.
19:07 And yeah, when we run this through
actual ColorErosion right here,
19:11 you'll see that, it just it
just really works for terrain like this.
19:16 And then we're going to use a Slope map
to, select the cliffs
19:20 and multiply that on our snow to make sure
there's no snow covering our cliffs.
19:26 Screen that onto our rocky
19:29 ground layer and throw it in the Light
X for some cool lighting.
19:35 And there we go.
19:36 Here is the cool snowy, alpine,
19:40 very high altitude mountain
19:43 terrain that you're going to get.
19:46 Now let's go for the Highland.
19:48 Starting off with the Mountain Erosion2.
19:52 So in this case
you'll notice a lot less duration here.
19:56 The Downcutting is one force.
19:57 It's a little stronger.
19:59 The Erosion Scale.
I kept it at a thousand.
20:01 Because this is clearly a less large scale
20:04 terrain than the, than the huge
alpine mountain here.
20:07 It's more of a hill than a mountain.
20:10 The actual Coarse Sediments and Bed Load
I didn't touch in this case
20:15 because I decided to add them
later on, the Shape controls.
20:19 So we have very similar
here Shape .5, .6 and .01.
20:25 I really
20:25 wanted this, this hill to be eroded
quite heavily as a whole.
20:29 Terrain.
20:29 So not too many, details still left.
20:32 It's a almost like a hill, basically.
20:35 I will add details to it.
20:37 The Shaper here
will just bulk up this hill,
20:41 so it's less pointy and a bit more round.
20:44 Sorry, I had an old node here
that was not doing anything.
20:47 But yeah, we're going to have a Warp
20:48 with a Max Blend mode,
and this is just going to give me cool
20:51 rocky outcrops to look at the settings
here.
20:55 Not super special.
20:56 But this is my way of just adding
instant cool detail
20:60 popping out of my terrain,
then Erosion2.
21:03 On top of that, we're going to add a way
21:05 smaller Erosion Scale
because this will just affect our small
21:10 like gullies here, just with smaller
erosion on the terrain visible everywhere.
21:16 And it's going to really help blend
21:17 these rocky outcrops into the terrain
that it's put on top of.
21:21 So you see here,
21:23 still no Bed Loads, still no Coarse
Sediments,
21:25 only a little bit of Shape control here
just to, have a little bit of thermal
21:30 erosion, blend this whole terrain
a bit better into each other.
21:33 And now we're going to use an Erosion2
with a Blend mode
21:36 set to Max to add the actual sediments.
21:40 So here we'll see our cool terrain.
21:43 However, these gullies are
of course ridiculously deep.
21:47 And then we're going to fill them up
with some sediments right here.
21:52 Duration.
21:52 Quite short DownCutting
quite low Erosion Scale set to a thousand
21:56 as that was kind of the scale
of the first here.
21:59 The first terrain with the big gullies,
you can see that it works very nicely.
22:04 And by keeping it all separated,
I'm able to increase the volume of debris
22:08 and all those kind of things
without affecting the underlying layer.
22:13 At this point I'm going to add some cool
rock detail.
22:16 Using a Perlin and a Fractal terracing.
22:18 I'm going to get really insane details
here.
22:21 Use a slope mask and then,
throw it out on top.
22:24 So we're going to get these cool,
kind of like,
22:28 sedimentary layers in our rock.
22:31 And at that point
we're going to have our Chokepoint.
22:34 Now the dusting here is going to be
our, you know, primary mode for snow.
22:39 I'm going to set the flow
to a very low number .001.
22:44 I do this because it blends a bit better
if you put it to point.
22:47 If you put it to zero.
22:49 I feel like the
the mask becomes very harsh.
22:52 So when you have the flow at a very low
amount, it won't flow over your cliffs
22:58 or like your sloped areas,
but it will still be a bit more soft.
23:02 And then to make it softer, we're going to
use ColorErosion with a high Diffusion,
23:07 which is kind of just
23:09 kind of blurred a bit naturally
23:13 for the texture of the mountain.
23:14 We're going to use a TextureBase
with two SatMaps.
23:17 We're going to get a SatMap for the rock
and a SatMap for the vegetation,
23:23 the SatMap for the vegetation
I further enhanced with a Soil mask
23:27 set to soft light,
which is just kind of going to darken
23:31 some of these areas and brighten
some of the other ones.
23:34 Just kind of going off of my reference
here, right? At this point,
23:38 I get a Slope mask with a Height
mask on top of it.
23:42 So we're basically creating the rocky
layer here and a rocky mask
23:46 all the, you know, dark areas
where we rock all the bright areas will be
23:50 grass and vegetation.
23:51 I'm going to run it through
a ColorErosion that is very strong,
23:55 and I'm going to set it to the Min
Blend mode.
23:57 This will preserve our,
you know, mask that is laid on underneath.
24:02 So we're only getting more rock flows.
24:05 Basically added to this using a Curve
to just strengthen and
24:09 making it more contrasty.
24:10 And then we blend the rock and vegetation
masks together.
24:14 Creating this underlying texture
to which we're going to add our snow
24:19 with Screen and then throw it
into LightX for cool lighting.
24:26 There you go.
24:27 Erosion2, creating
two totally different shapes,
24:31 very alpine shape and a Highland shape.
24:33 I hope this was very useful and
I hope you understand Erosion2 fully.
24:38 Now if not, hit me in the comments
with some questions.
24:42 I will definitely take a look
and see if I can help you guys out.
24:45 Thanks for watching and we will see you on
the next video explaining the next node.