In Green Custard's 13th Friday talk, Terry explores Procedural Land Generation. Topics covered: - Perlin Noise - 2D Perlin Noise - Uses - Octaves - Octaves result - Midpoint displacement - Diamond Square - Voronoi Tessellation Green Custard is a custom software development consultancy. To discover more about their work and the team visit www.green-custard.com.

1. Procedural Land Generation
24th August 2018

2. Perlin Noise
● Created by Ken Perlin for Tron in 1982
● Simplex Noise 2001

3. Perlin Noise
● Random value between 0 and 1
● Deterministic, will always produce the same value at the same time
● Equation of values over time

4. Perlin Noise
● Can still seem random depending on the sample time
● Offset and seed to change time sample placement

5. 2D Perlin Noise
3D noise also used for depth
(Minecraft)

6. Uses
● Natural behaviours
http://localhost:8080/src/
● Terrain generation Demo
○ Show Offset
○ Seed
● Many more..

7. Octaves
● Lacunarity (2)
● Increases the frequency
● For each octave:
○ Starting from 0
○ Increase the power by 1

8. Octaves result
● Persistence (0.5)
● Decreases the amplitude
● For each octave:
○ Starting from 0
○ Increase the power by 1

9. ● Back to unity

10. Midpoint displacement
● Find Corners
● Shove in random values
2 8
0 3

11. Midpoint displacement
● Find Corners
● Shove in random values
● Fill the edge with the average
value between the numbers
○ Add a random value to the result
2 5 8
1 5.5
0 1.5 3

12. Midpoint displacement
● Find Corners
● Shove in random values
● Fill the edge with the average
value between the numbers
○ Add a random value to the result
● Fill the center using the same
method
2 5 8
1 3.3 5.5
0 1.5 3

13. Midpoint displacement
● Find Corners
● Shove in random values
● Fill the edge with the average
value between the numbers
○ Add a random value to the result
● Fill the center using the same
method
● Fill the remaining values with
progressively smaller squares
2 3.5 5 8
1.5 2.83 4.15
1 2.15 3.3 5.5
0 1.5 3

14. Midpoint displacement
● Map size: 2n +1
○ So we can set the middle
● Looks great
● http://stevelosh.com/blog/2016/
02/midpoint-displacement/

15. Midpoint Displacement - Seems

16. Diamond Square
● Calculate the center by average
the corners
1 2 3
5 5 5
9 8 7

17. Diamond Square
● Calculate the center by average
the corners
● Then use half the first four
diamonds around the edge
1 3 3
5 5 5
9 8 7

18. Diamond Square
● Calculate the center by average
the corners
● Then use half the first four
diamonds around the edge
1 3 3
5 5 5
9 8 7

19. Diamond Square
● Calculate the center by average
the corners
● Then use half the first four
diamonds around the edge
● Then diagonal again
1 3 3
3 4
5 5 5
7 6
9 8 7

20. Diamond Square
● Calculate the center by average
the corners
● Then use half the first four
diamonds around the edge
● Then diagonal again
● Then diamonds
1 3 3
3 4 4
5 5 5
7 6
9 8 7

21. Diamond Square

22. Voronoi Tessellation

23. Resources
● Procedural Landmass Generation (E01 … E11)
○ https://www.youtube.com/watch?v=wbpMiKiSKm8
● KhanAcademy
○ https://www.khanacademy.org/computing/computer-programming/programming-natural-
simulations/programming-noise/a/perlin-noise
● Nature of code
○ Daniel Shiffman: https://natureofcode.com/
● Udemy: Procedural Terrain Generation
○ https://www.udemy.com/procedural-terrain-generation-with-unity/learn/v4/
● Steve Losh: http://stevelosh.com/blog/2016/02/midpoint-displacement/