From 64288a2b387d1e27fdb2c6e61ac6c8ff6366e721 Mon Sep 17 00:00:00 2001
From: Daniel Shiffman <daniel.shiffman@gmail.com>
Date: Thu, 3 Nov 2022 16:51:52 -0400
Subject: [PATCH] updating 3D Projection code

noticed this was missing the final step from the video! The next Apple II video covers this topic!
---
 .../CC_112_3D_Rendering.pde                   | 24 +++++++++----------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/112_3D_Rendering/Processing/CC_112_3D_Rendering/CC_112_3D_Rendering.pde b/112_3D_Rendering/Processing/CC_112_3D_Rendering/CC_112_3D_Rendering.pde
index 33a1f52..d609c14 100644
--- a/112_3D_Rendering/Processing/CC_112_3D_Rendering/CC_112_3D_Rendering.pde
+++ b/112_3D_Rendering/Processing/CC_112_3D_Rendering/CC_112_3D_Rendering.pde
@@ -1,19 +1,13 @@
-// Daniel Shiffman
-// http://youtube.com/thecodingtrain
-// http://codingtra.in
-
+// Daniel Shiffman / Coding Train
 // Coding Challenge #112: 3D Rendering with Rotation and Projection
+// https://thecodingtrain.com/challenges/112-3d-rendering-with-rotation-and-projection
 // https://youtu.be/p4Iz0XJY-Qk
+// p5: https://editor.p5js.org/codingtrain/sketches/r8l8XXD2A
 
 float angle = 0;
 
 PVector[] points = new PVector[8];
 
-float[][] projection = {
-  {1, 0, 0},
-  {0, 1, 0}
-};
-
 void setup() {
   size(600, 400);
 
@@ -57,6 +51,14 @@ void draw() {
     PVector rotated = matmul(rotationY, v);
     rotated = matmul(rotationX, rotated);
     rotated = matmul(rotationZ, rotated);
+
+    float distance = 2;
+    float z = 1 / (distance - rotated.z);
+    float[][] projection = {
+      {z, 0, 0},
+      {0, z, 0}
+    };
+
     PVector projected2d = matmul(projection, rotated);
     projected2d.mult(200);
     projected[index] = projected2d;
@@ -78,10 +80,6 @@ void draw() {
     connect(i, i+4, projected);
   }
 
-
-
-
-
   angle += 0.03;
 }