Last month I introduced some knowledge of rivers to our game making; this month I want to try and bring in some other natural features created by water by discussing coasts.
The coastline is a rather neglected aspect in a lot of RPG Maker games. Usually if you're at the coast you're either at an abrupt end of the land where the cliffs drop straight down into dead waters, or you're at a beach, which continues straight from grass to water with little transition between the two. Now this isn't necessarily a bad thing but I thought it would be interesting to explore these features and how they are made to try and bring a sense of realism to level design.
Firstly, we need to know how the coast itself is created. Basically a coast is just an area where the land meets the sea, created by tectonic plate movements and whatnot; all we need to know is that rocks meet sea, and the sea acts upon the rocks with immense force along the way. Cliffs are not made of one type of rock (we discussed this in a previous issue on rivers) meaning some rocks are much harder than others. In our games, we can represent these quite accurately, but some simple cliff tiles will probably suffice. Sandstone is hard, as is granite. Limestone and clay are soft. Chalk is I believe somewhere in the middle.
There tend to be lines where two types of rock meet, in a zebra-crossing pattern of hard, harder soft, hard, etc. This all has much influence on how the sea erodes (or doesn't erode) each bit of rock. You can probably guess what happens, but won't realise the features this creates: what we end up with is a wavy line of sticky-out-bits (“headland”) and bits curving inwards wherever the rock is weaker (“bays”). In these bays the water has been slowed down by the headstones, and as we discussed on rivers, where water is slower it tends to drop whatever it is carrying. In this case this is sand, and so in these bays is where we end up with our beaches.
Water is forced in at whatever direction the waves are moving. When it comes back out again it is slower, and so instead follows the contours of the land – this means it goes in one direction and out another – and it takes the sand along with it. This process, called “longshore drift”, makes the beaches move along the coast. So, your map will have two headlands with a beach in the middle – but the sand will be mostly pushed up against one of the headlands in particular.
When erosion does finally manage to break it's way through the headland it creates some interesting geological features which we will get to shortly; for now all we need to know is that when it does break through the beach can be snatched altogether and end up further down the coast. Sandy beaches slow down the water decreasing erosion, so in contrast, when the beach is taken away, the land is much more vulnerable. This leaves any settlements on top in a very precarious position!
So what are these interesting features created by the erosion of the headland? You'll recognise a lot of them from the best coastal photographs, and they're all created in the same way. First, we need to be talking about a very specific type of headland – a thin strip between two bays open and at risk of erosion. The water also has to be hitting it from the right angle for it to erode horizontally through the thin peninsular.
As the water is at the bottom of the landmass and not eroding the top at all, we first of all end up with a cave, carved out of the side of the rock. This cave gradually gets deeper and deeper, working it's way through the rock. These caves will make interesting locations in games, but a more unique feature is what happens when the back of the wall is broken through, as it creates a sea arch. This arch can be wide enough for boats to pass through. It would make a good transition between two coastal maps as it creates a pinch point perfect for the teleport events and such.
The rock continues to be eroded, and if there is soil on top it is worn down from above at the same time, and eventually if the rock is low enough the top of the cave collapses, forming boulders at the bottom of the cave. We now have a shorter headland and a structure called a stack at the end. There can be multiple stacks, in a long line, along a headland and they make a really interesting landscape – the RPG Maker XP tilesets actually come with tiles for stacks and the boulders inbetween them but I have never seen them used in their correct context.
Eventually the stack gets eroded around the base being shaped gradually to resemble an egg-timer. Eventually the top just falls off and crumbles into the sea. This leaves a sharp point sticking out of the water – called a needle.
All of this makes for very dangerous sailing for anybody approaching by boat or ship. Lighthouses, rather than being located on land as often in RPG Maker games, are usually located at the end of a headland – on a large enough needle – to stop boats hitting the stacks and fallen rocks between them.
Who said coasts had to be boring?
The coastline is a rather neglected aspect in a lot of RPG Maker games. Usually if you're at the coast you're either at an abrupt end of the land where the cliffs drop straight down into dead waters, or you're at a beach, which continues straight from grass to water with little transition between the two. Now this isn't necessarily a bad thing but I thought it would be interesting to explore these features and how they are made to try and bring a sense of realism to level design.
Firstly, we need to know how the coast itself is created. Basically a coast is just an area where the land meets the sea, created by tectonic plate movements and whatnot; all we need to know is that rocks meet sea, and the sea acts upon the rocks with immense force along the way. Cliffs are not made of one type of rock (we discussed this in a previous issue on rivers) meaning some rocks are much harder than others. In our games, we can represent these quite accurately, but some simple cliff tiles will probably suffice. Sandstone is hard, as is granite. Limestone and clay are soft. Chalk is I believe somewhere in the middle.
There tend to be lines where two types of rock meet, in a zebra-crossing pattern of hard, harder soft, hard, etc. This all has much influence on how the sea erodes (or doesn't erode) each bit of rock. You can probably guess what happens, but won't realise the features this creates: what we end up with is a wavy line of sticky-out-bits (“headland”) and bits curving inwards wherever the rock is weaker (“bays”). In these bays the water has been slowed down by the headstones, and as we discussed on rivers, where water is slower it tends to drop whatever it is carrying. In this case this is sand, and so in these bays is where we end up with our beaches.
Water is forced in at whatever direction the waves are moving. When it comes back out again it is slower, and so instead follows the contours of the land – this means it goes in one direction and out another – and it takes the sand along with it. This process, called “longshore drift”, makes the beaches move along the coast. So, your map will have two headlands with a beach in the middle – but the sand will be mostly pushed up against one of the headlands in particular.
When erosion does finally manage to break it's way through the headland it creates some interesting geological features which we will get to shortly; for now all we need to know is that when it does break through the beach can be snatched altogether and end up further down the coast. Sandy beaches slow down the water decreasing erosion, so in contrast, when the beach is taken away, the land is much more vulnerable. This leaves any settlements on top in a very precarious position!
So what are these interesting features created by the erosion of the headland? You'll recognise a lot of them from the best coastal photographs, and they're all created in the same way. First, we need to be talking about a very specific type of headland – a thin strip between two bays open and at risk of erosion. The water also has to be hitting it from the right angle for it to erode horizontally through the thin peninsular.
As the water is at the bottom of the landmass and not eroding the top at all, we first of all end up with a cave, carved out of the side of the rock. This cave gradually gets deeper and deeper, working it's way through the rock. These caves will make interesting locations in games, but a more unique feature is what happens when the back of the wall is broken through, as it creates a sea arch. This arch can be wide enough for boats to pass through. It would make a good transition between two coastal maps as it creates a pinch point perfect for the teleport events and such.
The rock continues to be eroded, and if there is soil on top it is worn down from above at the same time, and eventually if the rock is low enough the top of the cave collapses, forming boulders at the bottom of the cave. We now have a shorter headland and a structure called a stack at the end. There can be multiple stacks, in a long line, along a headland and they make a really interesting landscape – the RPG Maker XP tilesets actually come with tiles for stacks and the boulders inbetween them but I have never seen them used in their correct context.
Eventually the stack gets eroded around the base being shaped gradually to resemble an egg-timer. Eventually the top just falls off and crumbles into the sea. This leaves a sharp point sticking out of the water – called a needle.
All of this makes for very dangerous sailing for anybody approaching by boat or ship. Lighthouses, rather than being located on land as often in RPG Maker games, are usually located at the end of a headland – on a large enough needle – to stop boats hitting the stacks and fallen rocks between them.
Who said coasts had to be boring?