# Terrain Generation
**URL:** https://discourse.processing.org/t/terrain-generation/28740
**Category:** Coding Questions
**Created:** [March 22, 2021, 7:49pm UTC](https://discourse.processing.org/t/terrain-generation/28740 "2021-03-22T19:49:21Z")
**Posts on this page:** 15
**Page:** 1
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 22, 2021, 7:49pm UTC](https://discourse.processing.org/t/terrain-generation/28740/1 "2021-03-22T19:49:21Z")
hi all
how to make this shape if any one can help
i found this equation :
centerpoint (x1, y1) and a radius r, the height of the hill at the point (x2, y2) is equivalent to:
how to use it to form this terrain
can and how if i can using it in this code
```auto
// Daniel Shiffman
// http://codingtra.in
// http://patreon.com/codingtrain
// Code for: https://youtu.be/IKB1hWWedMk
int cols, rows;
int scl = 20;
int w = 2000;
int h = 1600;
float flying = 0;
float[][] terrain;
void setup() {
size(600, 600, P3D);
cols = w / scl;
rows = h/ scl;
terrain = new float[cols][rows];
colorMode(HSB, 100, 100, 100);
}
void draw() {
flying -= 0.1;
float yoff = flying;
for (int y = 0; y < rows; y++) {
float xoff = 0;
for (int x = 0; x < cols; x++) {
terrain[x/2][y/2] = map(noise(xoff, yoff), 0, 1, -100, 100);
xoff += 0.2;
}
yoff += 0.2;
}
background(0);
// stroke(255);
//noFill();
//noStroke();
translate(width/2, height/2+50);
rotateX(PI/3);
translate(-w/2, -h/2);
for (int y = 0; y < rows-1; y++) {
// beginShape(TRIANGLE_STRIP);
beginShape(TRIANGLE_STRIP);
for (int x = 0; x < cols; x++) {
float z = terrain[x][y];
fill(z+20, 100, 100);
vertex(x*scl, y*scl, z);
float z1 = terrain[x][y+1];
fill(z1+20, 100, 100);
vertex(x*scl, (y+1)*scl, z1);
//rect(x*scl, y*scl, scl, scl);
}
endShape();
}
}
```
thanks for all
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [March 22, 2021, 9:35pm UTC](https://discourse.processing.org/t/terrain-generation/28740/2 "2021-03-22T21:35:36Z")
I couldn’t do it
```auto
// Daniel Shiffman
// http://codingtra.in
// http://patreon.com/codingtrain
// Code for: https://youtu.be/IKB1hWWedMk
int cols, rows;
int scl = 20;
int w = 2000;
int h = 1600;
float flying = 0;
float[][] terrain;
void setup() {
size(1600, 900, P3D);
cols = w / scl;
rows = h/ scl;
terrain = new float[222][222];
colorMode(HSB, 100, 100, 100);
// -----
flying -= 0.1;
float x1= 230; // w/2;
float y1= 230; // h/2;
float r = 5.015;
float yoff = 0;
int y3=0;
for (int y = -100; y < 100; y++) {
float xoff = 0;
int x3=0;
for (int x = -100; x < 100; x++) {
float a1 = ( pow2 ( xoff-x1 )) + ( pow2 (yoff-y1) ) ;
float b1 = (r*r) - a1; // map(noise(xoff, yoff), 0, 1, -100, 100);
terrain[x3][y3] = map(b1, -100000, 100000, -3000, 3000);
println(b1);
xoff += 4;
x3++;
}
yoff += 4;
y3++;
}
}
float pow2 ( float in_) {
return
in_*in_;
}
void draw() {
background(0);
lights();
// stroke(255);
//noFill();
//noStroke();
translate(width/2, height/2-222, -600);
rotateX(PI/3);
translate(-w/2, -h/2);
for (int y = 0; y < rows-1; y++) {
// beginShape(TRIANGLE_STRIP);
beginShape(TRIANGLE_STRIP);
for (int x = 0; x < cols; x++) {
float z = terrain[x][y];
fill(z+20, 100, 100);
//noStroke();
vertex(x*scl, y*scl, z);
float z1 = terrain[x][y+1];
fill(z1+20, 100, 100);
vertex(x*scl, (y+1)*scl, z1);
//rect(x*scl, y*scl, scl, scl);
}
endShape();
}
}
//
```
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 22, 2021, 9:46pm UTC](https://discourse.processing.org/t/terrain-generation/28740/3 "2021-03-22T21:46:45Z")
> [@Chrisir](#):
>
> I couldn’t do it
it is more than great that you give it a try ❤
i played with this line once got some change
```auto
float z = terrain[x^2][y^2];
```
and once again with this got some change
```auto
terrain[x^2][y^2] = map(noise(xoff, yoff), 0, 1, -100, 100);
```
i am still learning i found this site few time a go
[https://mathcs.holycross.edu/~spl/old\_courses/126\_spring\_2004/handouts/02.25.04.html](https://mathcs.holycross.edu/~spl/old_courses/126_spring_2004/handouts/02.25.04.html)
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 22, 2021, 9:54pm UTC](https://discourse.processing.org/t/terrain-generation/28740/4 "2021-03-22T21:54:36Z")
its great maybe the equation above for the c++ here were i found it
[https://www.stuffwithstuff.com/robot-frog/3d/hills/hill.html](https://www.stuffwithstuff.com/robot-frog/3d/hills/hill.html)
your result is close
---
### Author:  [@jb4x](https://discourse.processing.org/u/jb4x)
#### Post date: [March 22, 2021, 9:59pm UTC](https://discourse.processing.org/t/terrain-generation/28740/5 "2021-03-22T21:59:23Z")
Hello @jafal,
The first equation you have is not correct.
The equation of a sphere is:
So you actually need a z² or to take the square root of the right side of your equation.
To implement it, you simply need to compute the z value of your grid depending on the x, y coordinates.
BUT you also need to check if you are in the sphere boundary. The equation is valid only for x and y coordinate within the sphere. Outside the sphere you want the height equal to 0.
Hope this piece of code helps you:
```auto
import peasy.PeasyCam;
PeasyCam cam;
float[][] terrain;
void setup() {
size(800, 600, P3D);
cam = new PeasyCam(this, 400);
terrain = new float[300][300];
colorMode(HSB, 100, 100, 100);
float x0= 150;
float y0= 150;
float r = 100;
for (int x = 0; x < terrain.length; x++) {
for (int y = 0; y < terrain[0].length; y++) {
if (r * r - ((x- x0) * (x - x0) + (y- y0) * (y - y0)) > 0) {
terrain[x][y] = sqrt(r * r - ((x- x0) * (x - x0) + (y- y0) * (y - y0)));
} else {
terrain[x][y] = 0;
}
}
}
}
void draw() {
background(20);
lights();
translate(-150, 0, -600);
rotateX(PI/3);
translate(0, 0);
for (int y = 0; y < terrain[0].length - 1; y++) {
beginShape(TRIANGLE_STRIP);
for (int x = 0; x < terrain.length; x++) {
fill(220, 40, 40);
noStroke();
vertex(x, y, terrain[x][y]);
vertex(x, y + 1, terrain[x][y + 1]);
}
endShape();
}
}
```
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 22, 2021, 10:23pm UTC](https://discourse.processing.org/t/terrain-generation/28740/6 "2021-03-22T22:23:52Z")
Hello @[jb4x](https://discourse.processing.org/u/jb4x)
it is charming and great i have said to @Chrisir maybe its for c++ as apart of the code
many thanks for you … i am totally new and fresh 😄 to processing and my way for understanding is to study sketches for a certain issue and make comparing
God with you warm greeting
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 23, 2021, 1:26am UTC](https://discourse.processing.org/t/terrain-generation/28740/7 "2021-03-23T01:26:12Z")
> [@jafal](#):
>
> Hello sir @[jb4x](https://discourse.processing.org/u/jb4x)
i just wonder why it is without mesh and how to make it looks like the red mesh ?
Thanks for you
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [March 23, 2021, 6:32am UTC](https://discourse.processing.org/t/terrain-generation/28740/8 "2021-03-23T06:32:06Z")
It’s because of noStroke()
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 23, 2021, 2:39pm UTC](https://discourse.processing.org/t/terrain-generation/28740/9 "2021-03-23T14:39:48Z")
hi
the photo i post is with stroke i add it
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 24, 2021, 3:36am UTC](https://discourse.processing.org/t/terrain-generation/28740/10 "2021-03-24T03:36:42Z")
@[Chrisir](https://discourse.processing.org/u/Chrisir)
peace upon you
I have been studying your code for one night and feel that the issue is how the grid constructed.
See the equation here gave a result with Mr [jb4x](https://discourse.processing.org/u/jb4x) code
```auto
terrain[x][y] = sqrt(r * r - ((x- x0) * (x - x0) + (y- y0) * (y - y0)));
```
i added the same equation with your code gave a close result because the dome appeared
And the square base remains to complete the shape
```auto
terrain[x3][y3] = (r * r - ((xoff-x1 ) * (xoff- x1) + (yoff- y1) * (yoff - y1)));
```
I tried to solve the problem, but I could not
Do you have any suggestions?
```auto
// Daniel Shiffman
// http://codingtra.in
// http://patreon.com/codingtrain
// Code for: https://youtu.be/IKB1hWWedMk
int cols, rows;
int scl = 25;
int w = 2000;
int h = 2200;
float flying = 0;
float[][] terrain;
void setup() {
size(800, 900, P3D);
cols = w / scl;
rows = h/ scl;
terrain = new float[222][222];
colorMode(HSB, 100, 100, 100);
// -----
flying -= 0.1;
float x1= 230; // w/2;
float y1= 230; // h/2;
float r = 5.015;
float yoff = 0;
int y3=0;
for (int y = -100; y < 100; y++) {
float xoff = 0;
int x3=0;
for (int x = -100; x < 100; x++) {
// float a1 = ( pow2 ( xoff-x1 )) + ( pow2 (yoff-y1) ) ;
//float b1 = (r*r) - a1; // map(noise(xoff, yoff), 0, 1, -100, 100);
terrain[x3][y3] = (r * r - ((xoff-x1 ) * (xoff- x1) + (yoff- y1) * (yoff - y1)));
// terrain[x3][y3] = map(b1, -100000, 100000, -3000, 3000);
// println(b1);
xoff += 4;
x3++;
}
yoff += 4;
y3++;
}
}
float pow2 ( float in_) {
return
in_*in_;
}
void draw() {
background(0);
lights();
// stroke(255);
//noFill();
//noStroke();
translate(width/2, height/2-222, -600);
rotateX(PI/3);
translate(-w/2, -h/2);
for (int y = 0; y < rows-1; y++) {
// beginShape(TRIANGLE_STRIP);
beginShape(TRIANGLE_STRIP);
for (int x = 0; x < cols; x++) {
float z = terrain[x][y];
fill(z+20, 100, 100);
//noStroke();
vertex(x*scl, y*scl, z);
float z1 = terrain[x][y+1];
fill(z1+20, 100, 100);
vertex(x*scl, (y+1)*scl, z1);
//rect(x*scl, y*scl, scl, scl);
}
endShape();
}
}
//
```
---
### Author:  [@Chrisir](https://discourse.processing.org/u/Chrisir)
#### Post date: [March 24, 2021, 6:41am UTC](https://discourse.processing.org/t/terrain-generation/28740/11 "2021-03-24T06:41:33Z")
jb4x code is much better than mine
In his code there is one line noStroke()
Comment it out or replace it with stroke(0);
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 30, 2021, 7:50pm UTC](https://discourse.processing.org/t/terrain-generation/28740/12 "2021-03-30T19:50:28Z")
[Chrisir](https://discourse.processing.org/u/Chrisir)
hi this is same [jb4x](https://discourse.processing.org/u/jb4x) code but more More flexible
```auto
int cols, rows;
int scl =15;
int w = 2000;
int h = 1600;
float flying = 0;
float[][] terrain;
import peasy.PeasyCam;
PeasyCam cam;
void setup() {
size(800, 800, P3D);
cam = new PeasyCam(this, 400);
cols = w / scl;
rows = h/ scl;
terrain = new float[cols][rows];
}
void draw() {
flying -= 0.1;
float yoff = flying;
for (int y = 0; y < rows; y++) {
float xoff = 0;
for (int x = 0; x < cols; x++) {
if (2222 - ((x- 53) * (x - 53) + (y- 53) * (y - 53)) > 0) {
terrain[x][y] = sqrt(2222 - ((x- 53) * (x - 53) + (y- 53) * (y - 53)))*12;
}
// terrain[x][y] = map(noise(xoff, yoff), 0, 1, -100, 100);
xoff += 0.2;
}
yoff += 0.2;
}
background(0,222,1);
// stroke(2,5,255);
stroke(5);
strokeWeight(7);
noFill();
scale(.2);
translate(width/2, height/2+50);
rotateX(PI/3);
translate(-w/2, -h/2);
for (int y = 0; y < rows-1; y++) {
beginShape(TRIANGLE_STRIP);
for (int x = 0; x < cols; x++) {
vertex(x*scl, y*scl, terrain[x][y]);
vertex(x*scl, (y+1)*scl, terrain[x][y+1]);
//rect(x*scl, y*scl, scl, scl);
}
endShape();
}
}
```
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 30, 2021, 7:51pm UTC](https://discourse.processing.org/t/terrain-generation/28740/13 "2021-03-30T19:51:51Z")
 
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 30, 2021, 7:56pm UTC](https://discourse.processing.org/t/terrain-generation/28740/14 "2021-03-30T19:56:47Z")
@[jb4x](https://discourse.processing.org/u/jb4x)
many thanks for you
---
### Author:  [@jafal](https://discourse.processing.org/u/jafal)
#### Post date: [March 30, 2021, 8:03pm UTC](https://discourse.processing.org/t/terrain-generation/28740/15 "2021-03-30T20:03:02Z")
