World Machine Community

General => Geology and Terrain => Topic started by: Victorsl on March 20, 2017, 01:06:14 PM

Title: coast erosion is too simple
Post by: Victorsl on March 20, 2017, 01:06:14 PM
Hey friends, I'm current finishing my ISLAND terrain for a UE4 game, and I'm having trouble with the coastline of the terrain. I have already put the coast erosion but the problem is that it doesn't seem to be real because the node by itself made a coastline with no variation and I don't know how to make it more random in terms of size and height(like the GTA V coast for exemple).
 I have tried this topic reply #5:
 http://forum.world-machine.com/index.php?topic=2375.0

"1)Use a simple eroded advanced perlin. Use a preset erosion like flood of slurry, or something, that doesn't have either low or very high sediment carry amount.
2)Mask it using a gaussian mask or something, within the extents.
3)Use Coast erosion masked on the deposition output of erosion. Also make sure you have reduced its hardness using a low-height constant hooked on the hardness input of coast erosion, because even reducing the beach size to the lowest value, it will still be pretty big compared to real world beaches"

It seems to be kind of the result that I want judging by the pictures, but since English it's not my primary language I wasn't able to reproduce it.

So if someone have any ideia of how to make it work please tell me.

Thanks for the attention.
Title: Re: coast erosion is too simple
Post by: Johnny on December 06, 2017, 11:11:48 AM
Hey there!

Late reply, I know... But I have been off for a while due to other priorities.

As I can see you are refering to my answer. It's been a while since I last laid my hands on WM, but I remember this case.

So, I know I might have sounded a bit greek on that reply (because I am Greek! hahaha...ha......*funny joke* :|), so it's not your fault for not understanding. I will try to put it as simply as I can. Unfortunately, my pc broke a while ago, and I am typing from one that cannot handle WM. So, I will not give you a formula,  instead I will try to help you understand how it works, so you make it freely yourself and in your style. :)

Simply put, from my emperical research on nature, my observation is that smooth sandy terrain landasses occur on the flowing parts of the landmass, or on the "insides" of the coastline, not all-around, except for some cases that the sandy landmass is high, or affected by natural phenomenons, like wind, thermal weathering, or sea weathering.

So, along a coastline: sand -> "insides"
                                rocks -> "outsides"

As a start, try masking a coast erosion on the deposition output of the common erosion. And see where you get from there. Not the flow one, it won't look that good. Here is a simply (and little bad) example:
 _______________                           ______________
 |EROSION           |-------------------|COAST EROSION|
 |         flow output|                          |   mask input     |
 |        wear output|                                     |
 |deposition output|-----------------------------|

There is a better and more realistic idea, which I was working a year ago, that works with maxing an erosion over another, though simple, pretty complicated to explain... So, your best bet here is when I have the chance to show you a .tmd example...

Good luck and cheers!

Title: Re: coast erosion is too simple
Post by: Victorsl on December 07, 2017, 06:46:30 AM
A few mouths ago I found the solution I was looking for... similar with what I understood from your original ideia but with a few modifications since I already had a complete terrain missing only the coast line complexity. So anyway you help me a lot with the original idea :D
Thank you a lot for the attention and reply.