Hello everyone, I am trying to make an accurate sky simulation in the voxel game I am working on, as an update. So far, I have day and night working, with clouds (though they are kind of buggy). However, I want to make a sun that rotates around the camera. I store this in a pshape. However, I was to make it rotateX() (rotate vertically). However, it just spins in tiny circle. How would I make the arc bigger and make it rotate around the camera?
Source:
import processing.core.PApplet;
import processing.core.PImage;
import processing.core.PVector;
import processing.core.PShape;
import processing.core.PConstants;
public class Sky {
PImage clouds;
PApplet app;
int r = 0, g = 0, b = 0;
public PVector pos = new PVector(0, 0, 0);
public PVector pos2 = new PVector(0, 0, 0);
public PVector pos3 = new PVector(0, 0, 0);
public PVector pos4 = new PVector(0, 0, 0);
public PVector pos5 = new PVector(0, 0, 0);
PShape skyShape;
boolean day;
boolean night;
int dayTime = 60000;
int sunsetColor = 0xFFFD5E53;
int dayColor = 0xFF82E6FF;
int nightColor = 0xFF1E1E1E;
int sunsetAnimTime = 10000;
boolean startTimer = false;
int inc = 0;
PShape c, c2, c3;
PShape sun;
int timer = (sunsetAnimTime/1000) * 60;
public Sky(PApplet p) {
app = p;
clouds = Minecraft.clouds;
pos = new PVector(0 * Minecraft.size, 256 * Minecraft.size, 0 * Minecraft.size);
pos2 = new PVector(0 * Minecraft.size, 256 * Minecraft.size, -128 * Minecraft.size);
pos3 = new PVector(0 * Minecraft.size, 256 * Minecraft.size, -256 * Minecraft.size);
pos4 = new PVector(0 * Minecraft.size, 256 * Minecraft.size, -128 * Minecraft.size);
pos5 = new PVector(0 * Minecraft.size, 256 * Minecraft.size, -256 * Minecraft.size);
float x1 = -5000;
float y1 = -5000;
float z1 = -5000;
float x2 = 5000;
float y2 = 5000;
float z2 = 5000;
sun = app.createShape();
sun.setTexture(Minecraft.sunImage);
sun.beginShape(PConstants.QUADS);
sun.noFill();
sun.noStroke();
sun.vertex(x1, y1, z1, 0f, 0f);
sun.vertex(x2, y1, z1, 1f, 0f);
sun.vertex(x2, y2, z1, 1f, 1f);
sun.vertex(x1, y2, z1, 0f, 1f);
sun.endShape();
x1 = -6400;
y1 = -6400;
z1 = -6400;
x2 = 6400;
y2 = 6400;
z2 = 6400;
c = app.createShape();
c.setTexture(Minecraft.clouds);
c.beginShape(PConstants.QUADS);
c.noFill();
c.noStroke();
c.vertex(x1, y1, z2, 0, 0);
c.vertex(x2, y1, z2, 1, 0);
c.vertex(x2, y1, z1, 1, 1);
c.vertex(x1, y1, z1, 0, 1);
c.endShape();
z1 -= 128 * Minecraft.size;
z2 -= 128 * Minecraft.size;
c2 = app.createShape();
c2.setTexture(Minecraft.clouds);
c2.beginShape(PConstants.QUADS);
c2.noFill();
c2.noStroke();
c2.vertex(x1, y1, z2, 0, 0);
c2.vertex(x2, y1, z2, 1, 0);
c2.vertex(x2, y1, z1, 1, 1);
c2.vertex(x1, y1, z1, 0, 1);
c2.endShape();
z1 -= 128 * Minecraft.size;
z2 -= 128 * Minecraft.size;
c3 = app.createShape();
c3.setTexture(Minecraft.clouds);
c3.beginShape(PConstants.QUADS);
c3.noFill();
c3.noStroke();
c3.vertex(x1, y1, z2, 0, 0);
c3.vertex(x2, y1, z2, 1, 0);
c3.vertex(x2, y1, z1, 1, 1);
c3.vertex(x1, y1, z1, 0, 1);
c3.endShape();
c3 = app.createShape();
c3.setTexture(Minecraft.clouds);
c3.beginShape(PConstants.QUADS);
c3.noFill();
c3.noStroke();
c3.vertex(x1, y1, z2, 0, 0);
c3.vertex(x2, y1, z2, 1, 0);
c3.vertex(x2, y1, z1, 1, 1);
c3.vertex(x1, y1, z1, 0, 1);
c3.endShape();
}
public void setColor(int x, int y, int z) {
r = x;
g = y;
b = z;
}
public void draw() {
if (((app.millis() / dayTime) & 1) == 0) {
if((((app.millis() + sunsetAnimTime) / dayTime) & 1) != 0) {
float a = PApplet.constrain(timer, 1, 100);
animateSky(a, sunsetColor, dayColor);
} else {
if((((app.millis() - sunsetAnimTime) / dayTime) & 1) != 0) {
float a = PApplet.constrain(timer, 1, 100);
animateSky(a, dayColor, sunsetColor);
} else {
app.background(dayColor);
}
}
} else {
if((((app.millis() + sunsetAnimTime) / dayTime) & 1) == 0) {
float a = PApplet.constrain(timer, 1, 100);
animateSky(a, sunsetColor, nightColor);
} else {
if((((app.millis() - sunsetAnimTime) / dayTime) & 1) == 0) {
float a = PApplet.constrain(timer, 1, 100);
animateSky(a, nightColor, sunsetColor);
} else {
app.background(nightColor);
}
}
}
if(startTimer) {
timer--;
}
if(timer < 1) {
startTimer = false;
timer = (sunsetAnimTime/1000) * 60;
}
PVector chunkPos = Minecraft.camera.chunkPos;
PVector p = Minecraft.camera.position;
/*
pos.z = chunkPos.z * (Chunk.w * Minecraft.size);
pos2.z = chunkPos.z * (Chunk.w * Minecraft.size);
pos3.z = chunkPos.z * (Chunk.w * Minecraft.size);
*/
pos.x = chunkPos.x * (Chunk.w * Minecraft.size);
pos2.x = chunkPos.x * (Chunk.w * Minecraft.size);
pos3.x = chunkPos.x * (Chunk.w * Minecraft.size);
app.pushMatrix();
app.translate(pos.x, pos.y, pos.z);
app.shape(c);
app.popMatrix();
app.pushMatrix();
app.translate(pos2.x, pos2.y, pos2.z);
app.shape(c2);
app.popMatrix();
app.pushMatrix();
app.translate(pos3.x, pos3.y, pos3.z);
app.shape(c3);
app.popMatrix();
app.pushMatrix();
app.translate(pos.x + 12800, pos.y, pos.z);
app.shape(c);
app.popMatrix();
app.pushMatrix();
app.translate(pos2.x + 12800, pos2.y, pos2.z);
app.shape(c2);
app.popMatrix();
app.pushMatrix();
app.translate(pos3.x + 12800, pos3.y, pos3.z);
app.shape(c3);
app.popMatrix();
app.pushMatrix();
app.translate(pos.x - 12800, pos.y, pos.z);
app.shape(c);
app.popMatrix();
app.pushMatrix();
app.translate(pos2.x - 12800, pos2.y, pos2.z);
app.shape(c2);
app.popMatrix();
app.pushMatrix();
app.translate(pos3.x - 12800, pos3.y, pos3.z);
app.shape(c3);
app.popMatrix();
app.pushMatrix();
app.translate(pos.x, pos.y, pos.z + 12800);
app.shape(c);
app.popMatrix();
app.pushMatrix();
app.translate(pos2.x, pos2.y, pos2.z + 12800);
app.shape(c2);
app.popMatrix();
app.pushMatrix();
app.translate(pos3.x, pos3.y, pos3.z + 12800);
app.shape(c3);
app.popMatrix();
app.pushMatrix();
app.translate(pos.x + 12800, pos.y, pos.z + 12800);
app.shape(c);
app.popMatrix();
app.pushMatrix();
app.translate(pos2.x + 12800, pos2.y, pos2.z + 12800);
app.shape(c2);
app.popMatrix();
app.pushMatrix();
app.translate(pos3.x + 12800, pos3.y, pos3.z + 12800);
app.shape(c3);
app.popMatrix();
app.pushMatrix();
app.translate(pos.x - 12800, pos.y, pos.z + 12800);
app.shape(c);
app.popMatrix();
app.pushMatrix();
app.translate(pos2.x - 12800, pos2.y, pos2.z + 12800);
app.shape(c2);
app.popMatrix();
app.pushMatrix();
app.translate(pos3.x - 12800, pos3.y, pos3.z + 12800);
app.shape(c3);
app.popMatrix();
app.pushMatrix();
app.translate(p.x, p.y, p.z + 12800);
app.rotateX(PApplet.radians(-inc));
app.shape(sun);
app.popMatrix();
if(pos.z >= (128 * Minecraft.size) + chunkPos.z * (Chunk.w * Minecraft.size)) {
pos.z = chunkPos.z * (Chunk.w * Minecraft.size) - (640 * Minecraft.size);
}
if(pos2.z >= (128 * Minecraft.size) + chunkPos.z * (Chunk.w * Minecraft.size) + 6400) {
pos2.z = chunkPos.z * (Chunk.w * Minecraft.size) - (512 * Minecraft.size);
}
if(pos3.z >= (128 * Minecraft.size) + chunkPos.z * (Chunk.w * Minecraft.size) + 12800) {
pos3.z = chunkPos.z * (Chunk.w * Minecraft.size) - (384 * Minecraft.size);
}
if(pos4.z >= (128 * Minecraft.size) + chunkPos.z * (Chunk.w * Minecraft.size) + 6400) {
pos4.z = chunkPos.z * (Chunk.w * Minecraft.size) - (256 * Minecraft.size);
}
if(pos5.z >= (128 * Minecraft.size) + chunkPos.z * (Chunk.w * Minecraft.size) + 12800) {
pos5.z = chunkPos.z * (Chunk.w * Minecraft.size) - (128 * Minecraft.size);
}
pos.z += 16;
pos2.z += 16;
pos3.z += 16;
pos4.z += 16;
pos5.z += 16;
inc++;
}
public void animateSky(float x, int col1, int col2) {
startTimer = true;
app.background(app.lerpColor(col1, col2, x / 100));
}
}
Minecraft is the class that holds data that this class uses, such as cube size and PImages. I am not showing it here.
Hey buddy, could you make a simple (simplified) version of the problem in the shape of a sketch we can run and take a look at, without any of the sky and dependent classes? You just want a sphere to rotate around the camera?
2 Likes
For a simplified version I would make a camera by using the QueasyCam library, and then get information from the camera to determine its position, and draw the sphere accordingly.
in a simple sketch like this:
import queasycam.*;
QueasyCam camera;
void setup() {
size(1000, 800, P3D);
camera = new QueasyCam(this);
}
void draw() {
background(0);
pushMatrix();
translate(0, 0, 0);
sphere(100);
popMatrix();
}
How would I get the sphere to rotate on the x axis, around the camera?
You can make an object rotate around a point by using basic trig:
float rad = 1000; // radius
float angle = frameCount / 100.f; // arbitrary value that determines the rotation speed
float x = rad * cos(angle);
float z = rad * sin(angle); // x, z is the horizontal plane
Add the camera.position to these values, translate to this position before you draw the sphere and you should be done?
2 Likes
Whats the difference between QueasyCam and PeasyCam?
http://mrfeinberg.com/peasycam/#about
It says in the description… (I wondered the same…) he named it in honour of Peasy; it’s a FPS adaptation, allowing you to move the camera with WASD.
2 Likes
Thank you for the solution. However, I have 1 more question.
- Would I use
tan()to make the sphere rotate on the y-axis?
Well, yes and no. You can look up spherical coordinates on wiki to understand how coordinates around a sphere work, but in this case it’d probably be easier to rotate your orbit using rotateX/Y/Z or rotation matrices. Like I suggested in my example, the combination of cos for one, and sin for the other makes a circle - to which components you connect them; x, y or z, determines how the circle is oriented.
x = cos(angle)
y = sin(angle)
makes the circle go vertical, aligned with the camera plane (you see a circle)
z = cos(angle)
x = sin(angle)
creates a horizontal circle
z = cos(angle)
y = sin(angle)
creates a vertical circle that’s perpendicular to the camera plane (you see the circle from the side: a line)