1 files changed, 61 insertions, 0 deletions
diff --git a/tools/3D-Reconstruction/sketch_3D_reconstruction/Ray_Tracing.pde b/tools/3D-Reconstruction/sketch_3D_reconstruction/Ray_Tracing.pde
new file mode 100644
index 000000000..ef4be691c
--- /dev/null
+++ b/tools/3D-Reconstruction/sketch_3D_reconstruction/Ray_Tracing.pde
@@ -0,0 +1,61 @@
+// Triangle
+class Triangle {
+  // position
+  PVector p1, p2, p3;
+  // color
+  color c1, c2, c3;
+  BoundingBox bbx;
+  Triangle(PVector p1, PVector p2, PVector p3, color c1, color c2, color c3) {
+    this.p1 = p1;
+    this.p2 = p2;
+    this.p3 = p3;
+    this.c1 = c1;
+    this.c2 = c2;
+    this.c3 = c3;
+    bbx = new BoundingBox();
+    bbx.create(this);
+  }
+  // check to see if a ray intersects with the triangle
+  boolean intersect(Ray r, float[] param) {
+    PVector p21 = PVector.sub(p2, p1);
+    PVector p31 = PVector.sub(p3, p1);
+    PVector po1 = PVector.sub(r.ori, p1);
+
+    PVector dxp31 = r.dir.cross(p31);
+    PVector po1xp21 = po1.cross(p21);
+    float denom = p21.dot(dxp31);
+    float t = p31.dot(po1xp21) / denom;
+    float alpha = po1.dot(dxp31) / denom;
+    float beta = r.dir.dot(po1xp21) / denom;
+
+    boolean res = t > 0 && alpha > 0 && alpha < 1 && beta > 0 && beta < 1 &&
+                  alpha + beta < 1;
+    // depth test
+    if (res && t < param[0]) {
+      param[0] = t;
+      param[1] = alpha * p1.x + beta * p2.x + (1 - alpha - beta) * p3.x;
+      param[2] = alpha * p1.y + beta * p2.y + (1 - alpha - beta) * p3.y;
+      param[3] = alpha * p1.z + beta * p2.z + (1 - alpha - beta) * p3.z;
+    }
+    return res;
+  }
+  void render() {
+    beginShape(TRIANGLES);
+    fill(c1);
+    vertex(p1.x, p1.y, p1.z);
+    fill(c2);
+    vertex(p2.x, p2.y, p2.z);
+    fill(c3);
+    vertex(p3.x, p3.y, p3.z);
+    endShape();
+  }
+}
+// Ray
+class Ray {
+  // origin and direction
+  PVector ori, dir;
+  Ray(PVector ori, PVector dir) {
+    this.ori = ori;
+    this.dir = dir;
+  }
+}