# Week 8 Homework

Life is pretty hectic right now, sorry for the delay in getting to this!

Here’s a sketch that explores the rotate and translate functions:
https://editor.p5js.org/nicoleannevella/sketches/C_zaN7RZk

JS Code:

```let d, a = 0;

function setup() {
createCanvas(windowWidth, windowHeight, WEBGL);
noStroke();
background(0);
colorMode(HSB, 360, 100, 100);
}

function draw() {
rotateX(a/QUARTER_PI);
rotateY(a/HALF_PI);
rotateZ(a/PI);

fill(frameCount % 360, 35, 100, 100);
translate(cos(a)*250, sin(a)*250);

d=tan(a)*(width/12);
sphere(d);

a+= 0.015;
}
```

Here’s a sketch that attempts to do the same but with moving a camera object:
https://editor.p5js.org/nicoleannevella/sketches/CE3m6hUmo

JS Code:

```// camera object and position
let cam;
let camPos;

// set min and max depth of field
let maxdof = 1500;
let mindof = 1;

let a = 0; // angle used for cos/sin animations

function setup() {
createCanvas(windowWidth, windowHeight, WEBGL);

// use the HSB coloe mode because it makes most sense to me
colorMode(HSB, 360, 100, 100);

// init our camera and use a vector for its position
cam = createCamera();
camPos = createVector();

// strokes can be ugly sometimes, lets not use one
noStroke();
}

function draw() {

// animate the fov with cos() by an increasing angle value
let fov = cos(a)*2;
let aspect = width / height;

// animate the camera look at positions using the same
// increasing angle value and some cos/sin functions
// if we divide the angle by some number we can add
// a sense of "randomness" to it
let camLookX = cos(a) * sin(a / HALF_PI) * maxdof * 0.1;
let camLookY = cos(a) * sin(a / PI) * maxdof * 0.1;
let camLookZ = cos(a) * sin(a / QUARTER_PI) * maxdof * 0.1;

// set the perspective, position, and lookAt for our 3D camera
cam.perspective(fov, aspect, mindof, maxdof);
cam.setPosition(cos(a) * maxdof, 0, -10);
cam.lookAt(camLookX, camLookY, camLookZ);

// animate that fill nicely with the Hue based on framecount
fill(frameCount % 360, 35, 100, 100);

// draw a sphere
sphere(10);

// the magic value used to caluclate cos/sin that's resposible for all our animations
a += 0.015;
}
```

Here’s a sketch where I add my liquid gold frag shader to the blob obj file that Jeremy made in Blender. Hope it’s ok that I stole your .obj (obviously I am going to try to get my delicious gold involved somehow).

Getting my gold fragment shader to map onto the 3D object was not trivial. I had to try out all the possible mappings like vEyePosition, vModelView, etc … I set the st to vScreenPosition.xy/vNormal.xy and that showed progress.

The larger issue was how to get my circles drawn in the right place. As it’s no longer a vec2, but a vec3. So, in the drawCircle function, I had to add the three xyz values of vNormal to get it to draw correctly onto the shape.

#define drawCircle(st,pos,size)smoothstep(0.,5./(vNormal.x+vNormal.y+vNormal.z),size-length(pos-st))

https://editor.p5js.org/nicoleannevella/sketches/sEj2HwGv3

```#ifdef GL_ES
precision mediump float;
#endif

uniform float uTime;

varying vec3 vScreenPosition;
varying vec3 vNormal;

#define drawCircle(st,pos,size)smoothstep(0.,5./(vNormal.x+vNormal.y+vNormal.z),size-length(pos-st))

#define PI 3.14159265358979323846
#define TWO_PI 6.283185307179586
#define BUTTER TWO_PI/TWO_PI/TWO_PI/TWO_PI/TWO_PI/TWO_PI

vec3 permute(vec3 x){return mod(((x*34.)+1.)*x,289.);}

float snoise(vec2 v){
const vec4 C=vec4(.211324865405187,.366025403784439,
-.577350269189626,.024390243902439);
vec2 i=floor(v+dot(v,C.yy));
vec2 x0=v-i+dot(i,C.xx);
vec2 i1;
i1=(x0.x>x0.y)?vec2(1.,0.):vec2(0.,1.);
vec4 x12=x0.xyxy+C.xxzz;
x12.xy-=i1;
i=mod(i,289.);
vec3 p=permute(permute(i.y+vec3(0.,i1.y,1.))
+i.x+vec3(0.,i1.x,1.));
vec3 m=max(.5-vec3(dot(x0,x0),dot(x12.xy,x12.xy),
dot(x12.zw,x12.zw)),0.);
m=m*m;
m=m*m;
vec3 x=2.*fract(p*C.www)-1.;
vec3 h=abs(x)-.5;
vec3 ox=floor(x+.5);
vec3 a0=x-ox;
m*=1.79284291400159-.85373472095314*(a0*a0+h*h);
vec3 g;
g.x=a0.x*x0.x+h.x*x0.y;
g.yz=a0.yz*x12.xz+h.yz*x12.yw;
return 130.*dot(m,g);
}

void main() {

vec2 st=vScreenPosition.xy/vNormal.xy;
st.y=vScreenPosition.x/vScreenPosition.y;

st.x/=snoise(st+vec2(uTime*BUTTER,0.))*.5+.5;

float cs=snoise(st+uTime*BUTTER)*.5+.5;

float circ=drawCircle(st,vec2(.5),cs*TWO_PI);

vec3 red  =vec3(1.0,0.0,0.0);
vec3 green=vec3(0.0,1.0,0.0);
vec3 blue =vec3(0.0,0.0,1.0);

vec3 color = vec3(0.0);

color+=mix(color,red,circ);
color+=mix(color,green,circ);
color+=mix(color,blue,circ);

gl_FragColor = vec4(color, 1.0);
}
```

As a bonus, I added audio reactivity: