alice
September 29, 2019, 9:42pm
1
Hello, I have a question regarding the 3D view in processing : I’m trying to have a 3D view of the following code but looks like doesn’t work …
Cell[][] grid;
Cell[][] prev;
void setup() {
size(300, 300);
grid = new Cell[width][height];
prev = new Cell[width][height];
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j ++) {
float a = 1;
float b = 0;
grid[i][j] = new Cell(a, b);
prev[i][j] = new Cell(a, b);
}
}
for (int n = 0; n < 10; n++) {
int startx = int(random(20, width-20));
int starty = int(random(20, height-20));
for (int i = startx; i < startx+10; i++) {
for (int j = starty; j < starty+10; j ++) {
float a = 1;
float b = 1;
grid[i][j] = new Cell(a, b);
prev[i][j] = new Cell(a, b);
}
}
}
}
float dA = 1.0;
float dB = 0.5;
float feed = 0.055;
float k = 0.062;
class Cell {
float a;
float b;
Cell(float a_, float b_) {
a = a_;
b = b_;
}
}
void update() {
for (int i = 1; i < width-1; i++) {
for (int j = 1; j < height-1; j ++) {
Cell spot = prev[i][j];
Cell newspot = grid[i][j];
float a = spot.a;
float b = spot.b;
float laplaceA = 0;
laplaceA += a*-1;
laplaceA += prev[i+1][j].a*0.2;
laplaceA += prev[i-1][j].a*0.2;
laplaceA += prev[i][j+1].a*0.2;
laplaceA += prev[i][j-1].a*0.2;
laplaceA += prev[i-1][j-1].a*0.05;
laplaceA += prev[i+1][j-1].a*0.05;
laplaceA += prev[i-1][j+1].a*0.05;
laplaceA += prev[i+1][j+1].a*0.05;
float laplaceB = 0;
laplaceB += b*-1;
laplaceB += prev[i+1][j].b*0.2;
laplaceB += prev[i-1][j].b*0.2;
laplaceB += prev[i][j+1].b*0.2;
laplaceB += prev[i][j-1].b*0.2;
laplaceB += prev[i-1][j-1].b*0.05;
laplaceB += prev[i+1][j-1].b*0.05;
laplaceB += prev[i-1][j+1].b*0.05;
laplaceB += prev[i+1][j+1].b*0.05;
newspot.a = a + (dA*laplaceA - a*b*b + feed*(1-a))*1;
newspot.b = b + (dB*laplaceB + a*b*b - (k+feed)*b)*1;
newspot.a = constrain(newspot.a, 0, 1);
newspot.b = constrain(newspot.b, 0, 1);
}
}
}
void swap() {
Cell[][] temp = prev;
prev = grid;
grid = temp;
}
void draw() {
println(frameRate);
for (int i = 0; i < 1; i++) {
update();
swap();
}
loadPixels();
for (int i = 1; i < width-1; i++) {
for (int j = 1; j < height-1; j ++) {
Cell spot = grid[i][j];
float a = spot.a;
float b = spot.b;
int pos = i + j * width;
pixels[pos] = color((a-b)*255);
}
}
updatePixels();
}
Thanks !
1 Like
Chrisir
September 29, 2019, 10:08pm
2
There is a real 3D mode where you just say box
look at box in the reference
look at size() with P3D as third parameter
look at P3D tutorial in tutorials section
——
Also to have a black background use command background (0); at start of draw()
2 Likes
glv
September 29, 2019, 11:35pm
3
Hello,
I was not sure what you are looking for.
Your “growths” fill the screen so background(0) will not apply.
This inverted the colors so “growths” are white and background is black:
pixels[pos] = color(255-abs(a-b)*255);
Cool code!
3 Likes
alice
September 30, 2019, 12:06pm
4
Hi @glv and @Chrisir and thanks for your help, I watched the tutorial about P3D and I modified the code, now I have the 3D space with a box but I don’t see more the reaction diffusion …
@glv the code is just from Daniel Shiffman code!
Cell[][] grid;
Cell[][] prev;
void setup() {
size(300, 300, P3D);
translate(58, 48, 0);
rotateY(0.5);
noFill();
box(40);
grid = new Cell[width][height];
prev = new Cell[width][height];
for (int i = 0; i < width; i++) {
for (int j = 0; j < height; j ++) {
float a = 1;
float b = 0;
grid[i][j] = new Cell(a, b);
prev[i][j] = new Cell(a, b);
}
}
for (int n = 0; n < 10; n++) {
int startx = int(random(20, width-20));
int starty = int(random(20, height-20));
for (int i = startx; i < startx+10; i++) {
for (int j = starty; j < starty+10; j ++) {
float a = 1;
float b = 1;
grid[i][j] = new Cell(a, b);
prev[i][j] = new Cell(a, b);
}
}
}
}
float dA = 1.0;
float dB = 0.5;
float feed = 0.055;
float k = 0.062;
class Cell {
float a;
float b;
Cell(float a_, float b_) {
a = a_;
b = b_;
}
}
void update() {
for (int i = 1; i < width-1; i++) {
for (int j = 1; j < height-1; j ++) {
Cell spot = prev[i][j];
Cell newspot = grid[i][j];
float a = spot.a;
float b = spot.b;
float laplaceA = 0;
laplaceA += a*-1;
laplaceA += prev[i+1][j].a*0.2;
laplaceA += prev[i-1][j].a*0.2;
laplaceA += prev[i][j+1].a*0.2;
laplaceA += prev[i][j-1].a*0.2;
laplaceA += prev[i-1][j-1].a*0.05;
laplaceA += prev[i+1][j-1].a*0.05;
laplaceA += prev[i-1][j+1].a*0.05;
laplaceA += prev[i+1][j+1].a*0.05;
float laplaceB = 0;
laplaceB += b*-1;
laplaceB += prev[i+1][j].b*0.2;
laplaceB += prev[i-1][j].b*0.2;
laplaceB += prev[i][j+1].b*0.2;
laplaceB += prev[i][j-1].b*0.2;
laplaceB += prev[i-1][j-1].b*0.05;
laplaceB += prev[i+1][j-1].b*0.05;
laplaceB += prev[i-1][j+1].b*0.05;
laplaceB += prev[i+1][j+1].b*0.05;
newspot.a = a + (dA*laplaceA - a*b*b + feed*(1-a))*1;
newspot.b = b + (dB*laplaceB + a*b*b - (k+feed)*b)*1;
newspot.a = constrain(newspot.a, 0, 1);
newspot.b = constrain(newspot.b, 0, 1);
}
}
}
void swap() {
Cell[][] temp = prev;
prev = grid;
grid = temp;
}
void draw() {
background(0);
camera(mouseX, height/2, (height/2) / tan(PI/6), width/2, height/2, 0, 0, 1, 0);
translate(width/2, height/2, -100);
stroke(255);
noFill();
box(200);
println(frameRate);
for (int i = 0; i < 1; i++) {
update();
swap();
}
loadPixels();
for (int i = 1; i < width-1; i++) {
for (int j = 1; j < height-1; j ++) {
Cell spot = grid[i][j];
float a = spot.a;
float b = spot.b;
int pos = i + j * width;
//pixels[pos] = color((a-b)*255);
}
}
updatePixels();
}
1 Like
