1 files changed, 45 insertions, 0 deletions
diff --git a/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.py b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.py
new file mode 100644
index 0000000..6c0e810
--- /dev/null
+++ b/FSF-2020/calculus-of-several-variables/geometry-of-planes-and-curves/space-curves/file3_circletosphere.py
@@ -0,0 +1,45 @@
+from manimlib.imports import *
+
+class sphere(GraphScene, ThreeDScene):
+    CONFIG = {
+    'x_min': -10,
+    'x_max': 10,
+    'y_min': -10,
+    'y_max': 10,
+    'graph_origin': ORIGIN,
+    "x_axis_width": 10,
+    "y_axis_height": 10,
+    }
+    def construct(self):
+        XTD = self.x_axis_width/(self.x_max- self.x_min)
+        YTD = self.y_axis_height/(self.y_max- self.y_min)
+        circleeqn = TextMobject(r'Hence, $x^{2} + y^{2} = 2(r^{2} - u^{2})$')
+        plottext = TextMobject(r'$x = \sqrt{r^{2} - u^{2}}cos\theta$ \\ $y = \sqrt{r^{2} - u^{2}}sin\theta$').shift(2*UP + 3*RIGHT)
+
+
+        self.setup_axes()
+        self.play(FadeIn(self.axes), FadeIn(plottext))
+
+        dots = []
+        for t in range(19):
+            dot = Dot().shift((3*XTD*np.cos(t), 3*YTD*np.sin(t),0))
+            dots.append(dot)
+            self.play(FadeIn(dot), run_time = 0.2)
+        dots = VGroup(*dots)
+        circle = Circle(radius = 3*XTD).set_color(WHITE).set_stroke(width = 10)
+        self.play(FadeIn(circle), FadeOut(dots), FadeOut(plottext))
+        self.wait(2)
+
+
+        axes = ThreeDAxes(**self.CONFIG)
+        sph = Sphere(radius = 3).scale(0.5)
+        text2 = TextMobject(r'Setting $u = 3$,\\$z = u$').shift(4*YTD*UP + 5*XTD*RIGHT)
+
+        self.play(Transform(self.axes,axes), ReplacementTransform(circle, sph))
+        self.add(text2)
+        self.wait(2)
+        self.remove(text2)
+        self.move_camera(phi = 60*DEGREES, theta=45*DEGREES,run_time=5)
+        self.begin_ambient_camera_rotation(rate=0.03)
+        self.play(FadeOut(axes), FadeOut(sph), FadeOut(self.axes))
+        self.wait(1)