camera-techniques

# Camera Techniques Cinematic camera techniques for Manim animations. ## MovingCameraScene (2D) ### Basic Setup ```python from manim import * class MyScene(MovingCameraScene): def construct(self): # self.camera.frame is the camera # It's a VMobject that can be animated # Save initial state self.camera.frame.save_state() # ... scene content ``` ### Camera Properties ```python # Get current properties self.camera.frame.width # Frame width self.camera.frame.height # Frame height self.camera.frame.get_center() # Camera position # Set properties self.camera.frame.set(width=10) self.camera.frame.set(height=6) ``` ## Zoom Operations ### Zoom In (Make Larger) ```python # Scale down frame = zoom in self.play( self.camera.frame.animate.scale(0.5), # 2x zoom run_time=2 ) # Zoom to specific height self.play( self.camera.frame.animate.set(height=4), run_time=2 ) ``` ### Zoom Out (Show More) ```python # Scale up frame = zoom out self.play( self.camera.frame.animate.scale(2), # 0.5x zoom run_time=2 ) ``` ### Zoom to Object ```python # Fit object in frame with padding target = some_mobject self.play( self.camera.frame.animate .set(height=target.height * 1.5) .move_to(target), run_time=2 ) ``` ### Zoom Levels | Scale Factor | Effective Zoom | Use Case | |--------------|----------------|----------| | 0.25 | 4x zoom in | Fine detail | | 0.5 | 2x zoom in | Detail view | | 1.0 | Normal | Overview | | 2.0 | 0.5x zoom out | Wide shot | ## Pan Operations ### Pan to Object ```python self.play( self.camera.frame.animate.move_to(target), run_time=1.5 ) ``` ### Pan to Coordinates ```python self.play( self.camera.frame.animate.move_to([3, 2, 0]), run_time=1.5 ) ``` ### Pan with Offset ```python # Center slightly above target self.play( self.camera.frame.animate.move_to(target).shift(UP * 0.5), run_time=1.5 ) ``` ## Combined Operations ### Zoom + Pan ```python # Zoom into specific element self.play( self.camera.frame.animate .scale(0.3) .move_to(detail_element), run_time=2 ) ``` ### Smooth Multi-Step ```python # Step 1: Pan to area self.play( self.camera.frame.animate.move_to(area), run_time=1 ) # Step 2: Zoom in self.play( self.camera.frame.animate.scale(0.5), run_time=1.5 ) ``` ## Save/Restore Pattern ### Basic Usage ```python class MyScene(MovingCameraScene): def construct(self): # Setup main_content = self.create_content() # Save the overview state self.camera.frame.save_state() # Show overview self.wait(2) # Zoom to detail self.play( self.camera.frame.animate .set(height=detail.height * 2) .move_to(detail), run_time=2 ) # Explain detail self.wait(3) # Return to overview self.play(Restore(self.camera.frame), run_time=2) ``` ### Multiple Saves ```python # Save state 1 (overview) self.camera.frame.save_state() self.play(self.camera.frame.animate.scale(0.5).move_to(area1)) # Save state 2 (area1) state_area1 = self.camera.frame.copy() self.play(Restore(self.camera.frame)) # Back to overview # Later, return to area1 self.play(self.camera.frame.animate.become(state_area1)) ``` ## Line Width Management ### The Problem When zooming, line widths don't scale, causing: - Zoomed in: Lines appear thicker - Zoomed out: Lines appear thinner ### The Solution ```python class ConsistentLinesScene(MovingCameraScene): def construct(self): # Store initial values INITIAL_LINE_WIDTH = self.camera.cairo_line_width_multiple INITIAL_FRAME_WIDTH = config.frame_width # Create updater def maintain_line_width(m): proportion = self.camera.frame.width / INITIAL_FRAME_WIDTH self.camera.cairo_line_width_multiple = INITIAL_LINE_WIDTH * proportion # Attach to dummy mobject line_manager = Mobject() line_manager.add_updater(maintain_line_width) self.add(line_manager) # Now zoom operations maintain consistent lines # ... rest of scene ``` ### When to Use - Complex diagrams with many lines - Significant zoom changes (>2x) - When visual consistency matters ## Focus Transitions ### Sequential Focus Tour ```python elements = [element_a, element_b, element_c] self.camera.frame.save_state() for element in elements: # Zoom to element self.play( self.camera.frame.animate .set(height=element.height * 2) .move_to(element), run_time=1.5 ) # Time to observe self.wait(2) # Return to overview self.play(Restore(self.camera.frame), run_time=1.5) ``` ### Tour with Varying Zoom ```python tour_stops = [ (element_a, 1.5, 2.0), # (element, height_factor, wait_time) (element_b, 2.0, 1.5), (element_c, 1.2, 3.0), ] self.camera.frame.save_state() for element, height_factor, wait in tour_stops: self.play( self.camera.frame.animate .set(height=element.height * height_factor) .move_to(element), run_time=1.5 ) self.wait(wait) self.play(Restore(self.camera.frame), run_time=2) ``` ## ThreeDScene Camera ### Setup ```python class My3DScene(ThreeDScene): def construct(self): # Set initial orientation self.set_camera_orientation( phi=75 * DEGREES, # Polar angle (from z-axis) theta=-45 * DEGREES # Azimuthal angle (around z-axis) ) ``` ### Camera Rotation ```python # Rotate to new orientation self.move_camera( phi=60 * DEGREES, theta=-60 * DEGREES, run_time=2 ) # Continuous rotation self.begin_ambient_camera_rotation(rate=0.1) # rad/s self.wait(5) self.stop_ambient_camera_rotation() ``` ### 3D Zoom ```python # Adjust zoom self.set_camera_orientation(zoom=0.5) # Closer self.set_camera_orientation(zoom=2) # Further ``` ## Timing Guidelines | Movement | Duration | Notes | |----------|----------|-------| | Quick pan | 0.5-1.0s | Minor adjustment | | Standard pan | 1.5s | Normal movement | | Dramatic zoom in | 2.0-3.0s | Building focus | | Slow reveal zoom out | 3.0-4.0s | Grand reveal | | Restore overview | 2.0s | Return home | ## Rate Functions for Camera ```python # Smooth (default) - professional self.play( self.camera.frame.animate.move_to(target), rate_func=smooth ) # Rush effects - dramatic self.play( self.camera.frame.animate.scale(0.3), rate_func=rush_into # Accelerate at end ) self.play( Restore(self.camera.frame), rate_func=rush_from # Decelerate from start ) # Linear - mechanical feel self.play( self.camera.frame.animate.shift(RIGHT * 3), rate_func=linear ) ``` ## Complete Example ```python from manim import * class CameraDemo(MovingCameraScene): def construct(self): # Line width management INIT_WIDTH = self.camera.cairo_line_width_multiple INIT_FRAME = config.frame_width manager = Mobject() manager.add_updater(lambda m: setattr(self.camera, 'cairo_line_width_multiple', INIT_WIDTH * self.camera.frame.width / INIT_FRAME)) self.add(manager) # Create content circles = VGroup(*[ Circle(radius=0.5).move_to([x, y, 0]) for x in range(-4, 5, 2) for y in range(-2, 3, 2) ]) self.add(circles) # Save overview self.camera.frame.save_state() self.wait(1) # Zoom to center circle center = circles[len(circles)//2] self.play( self.camera.frame.animate .set(height=center.height * 3) .move_to(center), run_time=2 ) # Add detail label = Text("Center", font_size=12).next_to(center, UP, buff=0.1) self.play(Write(label)) self.wait(2) # Return to overview self.play( FadeOut(label), Restore(self.camera.frame), run_time=2 ) self.wait(1) ```