camera-techniques

name	camera-techniques
description	Camera manipulation including zoom, pan, save/restore state, line width compensation, and focus transitions.

Camera Techniques

Cinematic camera techniques for Manim animations.

MovingCameraScene (2D)

Basic Setup

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

# 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)

# 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)

# Scale up frame = zoom out
self.play(
    self.camera.frame.animate.scale(2),  # 0.5x zoom
    run_time=2
)

Zoom to Object

# 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

self.play(
    self.camera.frame.animate.move_to(target),
    run_time=1.5
)

Pan to Coordinates

self.play(
    self.camera.frame.animate.move_to([3, 2, 0]),
    run_time=1.5
)

Pan with Offset

# 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

# Zoom into specific element
self.play(
    self.camera.frame.animate
        .scale(0.3)
        .move_to(detail_element),
    run_time=2
)

Smooth Multi-Step

# 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

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

# 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

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

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

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

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

# 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

# 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

# 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

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)