Implementing a Zoom parameter to :class:~.ThreeDScene (#1929)

* add a zoom parameter

* adding zoom trackers

* implementing zoom in three_d_scene

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* updated typing error

* added test

* updated test

Co-authored-by: Iced-Tea3 <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: KingWampy <[email protected]>

Author: 3 people

manim/camera/three_d_camera.py

@@ -33,6 +33,7 @@ def __init__(
         phi=0,
         theta=-90 * DEGREES,
         gamma=0,
+        zoom=1,
         **kwargs
     ):
         """Initializes the ThreeDCamera
@@ -50,6 +51,7 @@ def __init__(
         self.phi = phi
         self.theta = theta
         self.gamma = gamma
+        self.zoom = zoom
         self.shading_factor = shading_factor
         self.default_distance = default_distance
         self.light_source_start_point = light_source_start_point
@@ -61,6 +63,7 @@ def __init__(
         self.theta_tracker = ValueTracker(self.theta)
         self.distance_tracker = ValueTracker(self.distance)
         self.gamma_tracker = ValueTracker(self.gamma)
+        self.zoom_tracker = ValueTracker(self.zoom)
         self.fixed_orientation_mobjects = {}
         self.fixed_in_frame_mobjects = set()
         self.reset_rotation_matrix()
@@ -90,6 +93,7 @@ def get_value_trackers(self):
             self.theta_tracker,
             self.distance_tracker,
             self.gamma_tracker,
+            self.zoom_tracker,
         ]
 
     def modified_rgbas(self, vmobject, rgbas):
@@ -178,6 +182,16 @@ def get_gamma(self):
         """
         return self.gamma_tracker.get_value()
 
+    def get_zoom(self):
+        """Returns the zoom amount of the camera.
+
+        Returns
+        -------
+        float
+            The zoom amount of the camera.
+        """
+        return self.zoom_tracker.get_value()
+
     def set_phi(self, value):
         """Sets the polar angle i.e the angle between Z_AXIS and Camera through ORIGIN in radians.
 
@@ -218,6 +232,16 @@ def set_gamma(self, value):
         """
         self.gamma_tracker.set_value(value)
 
+    def set_zoom(self, value):
+        """Sets the zoom amount of the camera.
+
+        Parameters
+        ----------
+        value : int, float
+            The zoom amount of the camera.
+        """
+        self.zoom_tracker.set_value(value)
+
     def reset_rotation_matrix(self):
         """Sets the value of self.rotation_matrix to
         the matrix corresponding to the current position of the camera
@@ -271,6 +295,7 @@ def project_points(self, points):
         """
         frame_center = self.frame_center
         distance = self.get_distance()
+        zoom = self.get_zoom()
         rot_matrix = self.get_rotation_matrix()
 
         points = points - frame_center
@@ -288,7 +313,7 @@ def project_points(self, points):
             else:
                 factor = distance / (distance - zs)
                 factor[(distance - zs) < 0] = 10 ** 6
-            points[:, i] *= factor
+            points[:, i] *= factor * zoom
         return points
 
     def project_point(self, point):

manim/scene/three_d_scene.py

@@ -51,6 +51,7 @@ def set_camera_orientation(
         phi: Optional[float] = None,
         theta: Optional[float] = None,
         gamma: Optional[float] = None,
+        zoom: Optional[float] = None,
         distance: Optional[float] = None,
         frame_center: Optional[Union["Mobject", Sequence[float]]] = None,
     ):
@@ -71,6 +72,9 @@ def set_camera_orientation(
         gamma : int or float, optional
             The rotation of the camera about the vector from the ORIGIN to the Camera.
 
+        zoom : float, optional
+            The zoom factor of the scene.
+
         frame_center : list, tuple or np.array, optional
             The new center of the camera frame in cartesian coordinates.
 
@@ -83,6 +87,8 @@ def set_camera_orientation(
             self.renderer.camera.set_distance(distance)
         if gamma is not None:
             self.renderer.camera.set_gamma(gamma)
+        if zoom is not None:
+            self.renderer.camera.set_zoom(zoom)
         if frame_center is not None:
             self.renderer.camera._frame_center.move_to(frame_center)
 
@@ -166,6 +172,7 @@ def move_camera(
         phi: Optional[float] = None,
         theta: Optional[float] = None,
         gamma: Optional[float] = None,
+        zoom: Optional[float] = None,
         distance: Optional[float] = None,
         frame_center: Optional[Union["Mobject", Sequence[float]]] = None,
         added_anims: Iterable["Animation"] = [],
@@ -189,6 +196,9 @@ def move_camera(
         gamma : int or float, optional
             The rotation of the camera about the vector from the ORIGIN to the Camera.
 
+        zoom : int or float, optional
+            The zoom factor of the camera.
+
         frame_center : list, tuple or np.array, optional
             The new center of the camera frame in cartesian coordinates.
 
@@ -202,6 +212,7 @@ def move_camera(
             (theta, self.renderer.camera.theta_tracker),
             (distance, self.renderer.camera.distance_tracker),
             (gamma, self.renderer.camera.gamma_tracker),
+            (zoom, self.renderer.camera.zoom_tracker),
         ]
         for value, tracker in value_tracker_pairs:
             if value is not None:

tests/control_data/graphical_units_data/threed/CameraMove.npz

@@ -55,14 +55,14 @@ def test_CameraMoveAxes(scene):
     axes = ThreeDAxes()
     scene.add(axes)
     scene.add(Dot([1, 2, 3]))
-    scene.move_camera(phi=PI / 8, theta=-PI / 8, frame_center=[1, 2, 3])
+    scene.move_camera(phi=PI / 8, theta=-PI / 8, frame_center=[1, 2, 3], zoom=2)
 
 
 @frames_comparison(base_scene=ThreeDScene)
 def test_CameraMove(scene):
     cube = Cube()
     scene.add(cube)
-    scene.move_camera(phi=PI / 4, theta=PI / 4, frame_center=[0, 0, -1])
+    scene.move_camera(phi=PI / 4, theta=PI / 4, frame_center=[0, 0, -1], zoom=0.5)
 
 
 @frames_comparison(base_scene=ThreeDScene)