Advanced Techniques Guide

This guide covers sophisticated techniques and features of the RTMC130 Motion Control System that allow for more complex and creative camera movements. These advanced capabilities enable precise control for specialized cinematography applications.

Virtual Axes Setup and Operation

Virtual axes allow you to control the system in terms of intuitive camera movements rather than individual motor axes, making complex shots more manageable.

Understanding Virtual Axes

A virtual axis is a software-defined combination of multiple physical axes that behave as a single unit. For example, instead of thinking in terms of "Pan motor" and "Track motor," you can create a virtual axis called "Arc" that combines both to create an orbiting camera movement.

Benefits of Virtual Axes

• Simplifies control of complex multi-axis movements
• Provides more intuitive control of camera perspective
• Enables more natural hand-operated movements
• Allows for precise coordination between axes
• Makes repeatable complex movements easier to program

Setting Up Virtual Axes

1. Access the Virtual Axis Setup:
   • From the main Control Panel, type va (Virtual Axes) and press Enter
   • Alternatively, press JOG32 + STOP/CANCEL on the jogbox
2. Define a Virtual Axis:
   • Select the virtual axis number you want to configure (e.g., V1, V2)
   • Assign the physical axes that will contribute to this virtual axis
   • Set the contribution ratio for each physical axis
   • Name the virtual axis (e.g., "Arc," "Boom," "Crane")
3. Example Configuration:

   To create a virtual "Arc" that combines Pan and Track:

   Virtual Axis: V1
   Name: ARC
   Physical Axis 1: 5 (Pan)    Ratio: 1.000
   Physical Axis 2: 1 (Track)  Ratio: 0.050
   Physical Axis 3: 0 (None)   Ratio: 0.000

   This creates a virtual axis where for every degree of pan, the track moves 0.05 units, creating an arcing movement around a subject.

Using Virtual Axes

1. Activate Virtual Axes Mode:
   • Press JOG32 + STOP/CANCEL on the jogbox to toggle virtual axes mode
   • The jogbox display will show "VA MODE" when active
2. Select a Virtual Axis:
   • In VA MODE, press the number of the virtual axis (e.g., 1 for V1)
   • The jogbox will display the virtual axis name
3. Controlling the Virtual Axis:
   • Use the + and - jogbox buttons to move the virtual axis
   • All contributing physical axes will move proportionally according to their ratios
   • For recording, set all physical axes to REC mode

Common Virtual Axis Configurations

Complex Camera Choreography with Multi-Pass Recording

Multi-pass recording allows you to build complex movements by recording different axes in separate passes while playing back previously recorded moves.

Multi-Pass Recording Concept

Rather than trying to control all axes simultaneously, multi-pass recording lets you focus on a subset of axes in each recording session. This is particularly useful for movements that require different types of coordination or timing.

Multi-Pass Recording Process

1. First Pass: Primary Movement
   • Set only the primary axes to REC mode (e.g., Track and Pan)
   • Record or keyframe the primary movement
   • Run and review the movement to ensure it's as desired
2. Second Pass: Secondary Movement
   • Set the primary axes to NEUT mode (this maintains their movement but doesn't record new data)
   • Set secondary axes to REC mode (e.g., Focus and Tilt)
   • Play the primary movement while simultaneously recording the secondary axes
   • This allows you to match the secondary movement to the primary one
3. Additional Passes:
   • Continue with additional passes for tertiary movements or refinements
   • Each time, set only the axes you want to modify to REC mode
   • Keep previously completed axes in NEUT mode

Example: Creating a Complex Movement in Passes

Advanced Multi-Pass Techniques

• Reference Points: Use frame numbers or physical markers to identify key synchronization points across passes
• Partial Passes: Record only portions of a movement in a pass by using sn (Set NEUT) and sr (Set REC) at specific frames
• Compositional Refinement: Add subtle pan/tilt adjustments in a final pass to perfect framing
• Correction Passes: Fix problems in specific axes without affecting others

Go-Motion and Motion Blur Techniques

Go-motion is a specialized technique that creates natural motion blur in stop-motion animation by precisely moving the camera during the exposure.

Understanding Go-Motion

Traditional stop-motion animation lacks motion blur because each frame is captured with the subject stationary. Go-motion overcomes this limitation by:

• Moving the camera (or subject) during the exposure
• Creating natural motion blur in the captured frame
• Precisely calculating the blur amount based on movement speed
• Resulting in more realistic, film-like animation

Setting Up Go-Motion

1. Access Stop Motion Controls:
   • From the main Control Panel, click the StopMotn button
   • Or type sm and press Enter
2. Configure Motion Types:
   • In the Stop Motion screen, locate the TYPE column
   • For each axis, set the appropriate motion type:
     • S (Still): No movement during exposure
     • B (Blur): Movement during exposure (Go-motion)
     • I (Index): Movement between exposures only
3. Configure Blur Parameters:
   • For each axis set to "B" type, configure:
     • Blur Amount: How much movement during exposure (percentage of frame movement)
     • Blur Duration: How long the movement occurs (in milliseconds)
     • Blur Shape: The acceleration curve of the blur movement
4. Camera Trigger Setup:
   • Configure the camera trigger in the Stop Motion menu
   • Set the exposure time to match your camera's settings
   • Ensure the trigger output is connected to your camera

Go-Motion Workflow

1. Create Base Movement:
   • Create a standard movement using keyframes or recording
   • This defines the primary positions at each frame
2. Calculate Blur Requirements:
   • Analyze the movement speed between each frame
   • Faster movements require more blur
   • Use the cb (Calculate Blur) command to automatically generate appropriate blur values
3. Execute the Shot:
   • In stop-motion mode, the system will:
     • Move to the exact position for each frame
     • Trigger the camera
     • Execute the blur movement during exposure
     • Move to the next frame position
     • Repeat for each frame

Advanced Go-Motion Techniques

Real-World Application: Character Animation

When shooting stop-motion character animation with camera movement:

1. Set character-controlled axes to I (Index) type
2. Set camera movement axes to B (Blur) type
3. This creates realistic camera blur while keeping characters sharp
4. Result: Professional-looking animation with natural motion blur

Working with Multiple Axes Simultaneously

Controlling and coordinating multiple axes simultaneously is essential for complex camera choreography. The RTMC130 system offers several specialized techniques for multi-axis control.

Multi-Axis Joystick Control

For real-time control of multiple axes:

1. Multi-Joystick Assignment:
   • Press JOYST AX + axis number to assign the jogbox knob to one axis
   • Connect external joysticks/encoders for additional axes
   • Configure encoder inputs in HardSet → Encoder Setup
2. Configure Control Modes:
   • For each axis, decide between Position and Velocity mode
   • Position: Direct mapping of controller position to axis position
   • Velocity: Controller deflection controls speed of movement
   • Toggle using POSN/VELO on the jogbox
3. Recording Multi-Axis Movements:
   • Set all controlled axes to REC mode
   • Start recording with rm (Record Move)
   • Manipulate all controllers simultaneously
   • The system records the integrated movement

Axis Grouping

For controlling multiple axes as a single unit:

1. Create an Axis Group:
   • Type ag (Axis Group) at the main Control Panel
   • Select the axes to include in the group
   • Define the master axis that will control the group
2. Using Axis Groups:
   • Once grouped, controlling the master axis affects all grouped axes
   • Each grouped axis moves according to its relationship to the master
   • Use gr (Group Ratio) to adjust individual axis response
3. Advanced Grouping Techniques:
   • Nested groups for complex hierarchical control
   • Temporary groups for specific sequences
   • Conditional grouping based on frame ranges

Coordinated Keyframing

For precise multi-axis coordination through keyframes:

1. Synchronized Keyframe Creation:
   • Position all axes as desired at a specific frame
   • Press MEMO KEY to set keyframes for all axes in REC mode
   • Use kf command for keyboard-based keyframe creation
2. Time-Aligned Keyframes:
   • Place keyframes at exact frame numbers across axes
   • Use the Graph Editor to inspect and adjust timing
   • Ensure motion peaks and transitions align properly
3. Curve Matching:
   • Apply the same curve types to related axes
   • Use the mc (Match Curves) command to copy curve types between axes
   • This maintains cohesion between related movements

Creating Specialized Effects

The RTMC130 system can create several specialized cinematographic effects through precise control and coordination of multiple axes.

Vertigo/Dolly Zoom Effect

The famous "Vertigo" effect creates the illusion that the background is stretching or compressing while the subject maintains the same apparent size.

1. Mathematical Relationship:
   • The key is maintaining a precise ratio between dollying (Track axis) and zooming
   • The mathematical formula: new_focal_length = original_focal_length × (original_distance / new_distance)
2. Implementation in RTMC130:
   • Use the vz (Vertigo Zoom) command to automatically calculate the correct relationship
   • Example: vz 1 10 96 80 8
   • This creates a move using Track (1) and Zoom (10), starting 96 inches from subject with 80mm focal length, ending 8 inches from subject
3. Manual Fine-Tuning:
   • Adjust keyframes in the Graph Editor if needed
   • Test the move while observing a subject with clear foreground/background separation
   • Make minor adjustments to zoom values for perfect subject size maintenance

Split-Diopter Effect

This technique simulates the optical effect of a split diopter lens, allowing two subjects at different distances to both be in focus.

1. Setup:
   • Position camera with both near and far subjects in frame
   • Create a move that rapidly shifts focus between near and far subjects
   • Set extremely short move duration (e.g., 2-3 frames)
2. Focus Pull Method:
   • Set up keyframes for Focus (9) axis
   • Use Linear curves for instantaneous transitions
   • Adjust timing to coincide with cuts or hidden by foreground movement

Multiplane Camera Effect

Create parallax animation similar to classic Disney multiplane camera work by controlling relative movement speeds of different layers.

1. Setup:
   • Position camera with multiple depth planes in view
   • Use Track (1) for primary camera movement
   • Set up virtual axis for each subject/plane that needs separate control
2. Parallax Control:
   • Use pc (Parallax Control) command to set up relative movement
   • Closer objects move faster than distant objects
   • Adjust parallax amount to control the 3D effect strength

Bullet-Time Effect

Create a frozen-time effect with camera movement around a subject, similar to the famous "Matrix" effect.

1. Setup:
   • Configure for stop-motion operation
   • Set all axes to I (Index) type
   • Create a circular move around subject using Track (1), E/W (4), and Pan (5)
2. Arc Calculation:
   • Use cc (Create Circle) command to generate perfect arc
   • Set incremental frames for stop-motion capture
   • Configure camera for consistent exposure

Mathematical Move Generation

The RTMC130 system includes powerful two-letter commands that can generate mathematically precise movements, allowing for complex camera choreography that would be difficult to program manually.

Built-in Mathematical Functions

These specialized commands generate complex movements based on mathematical functions:

Wave Functions for Organic Movement

Create natural, oscillating movements using wave-based functions:

1. Sine Wave Movement:
   • Use wm (Wave Move) command with sine type
   • Creates smooth, oscillating movement
   • Example: wm 6 5.000 3.0 0.0 0.0 s (creates sine wave on Tilt axis)
2. Damped Oscillation:
   • Combine wm with em for decreasing amplitude
   • Creates realistic settling motion
   • Example: First wm 6 5.000 4.0 0.0 0.0 s, then em 6a 1.0 0.1 0.8
3. Combined Waves:
   • Apply multiple wave functions to create complex movements
   • Stack waves with different frequencies for organic motion
   • Use different wave types (sine, square, triangle) for various effects

Compound Motion Generation

Create complex movements by combining multiple mathematical functions:

1. Spiral Movement:
   • Combine circular movement (cc) with gradual lift (em)
   • Example:
     1. cc 24.000 120 1 4 5 (creates circular XY movement)
     2. em 2 0.000 12.000 1.0 (adds linear vertical movement)
2. Pendulum Effect:
   • Use wm with decreasing amplitude for realistic pendulum
   • Example for swinging camera:
     1. wm 5 20.000 0.5 0.0 0.0 (creates oscillating Pan)
     2. em 5a 1.0 0.2 0.9 (applies exponential decay to amplitude)

External Triggers & Timecode Synchronization

The RTMC130 system can be synchronized with external devices using trigger signals and timecode, allowing for precise coordination with cameras, lighting, and other film equipment.

External Trigger Options

The system can both send and receive trigger signals:

1. Camera Trigger Output:
   • Connects to camera's remote trigger input
   • Configurable pulse width and timing
   • Can be set to trigger at specific frames or events
2. Effects Trigger Outputs:
   • Multiple trigger outputs for controlling external devices
   • Programmable to fire at specific frames
   • Useful for synchronizing practical effects, lighting changes, etc.
3. External Input Triggers:
   • Allow external devices to control move playback
   • Can start, stop, or jump to specific frames
   • Useful for synchronizing with live action or other systems

Configuring Trigger Outputs

1. Access Trigger Setup:
   • From the main Control Panel, access HardSet → Trigger Setup
   • Or type ts (Trigger Setup) at the command prompt
2. Configure Trigger Parameters:
   • Channel: Select output channel (1-8)
   • Mode: Continuous, Single Pulse, Multiple Pulse
   • Frame: Specify trigger frame or range
   • Duration: Set pulse width in milliseconds
   • Polarity: Active High or Active Low
3. Creating Trigger Sequences:
   • Set up multiple triggers at different frames
   • Create trigger patterns for complex synchronization
   • Save trigger setups with move files

SMPTE Timecode Synchronization

For professional production environments, the RTMC130 can be synchronized to SMPTE timecode:

1. Timecode Setup:
   • Connect external SMPTE timecode source to RTMC130 timecode input
   • Launch SMPTE.EXE utility for configuration
   • Set frame rate to match production standard (24, 25, 29.97, or 30 fps)
2. Timecode Modes:
   • Chase Mode: System follows external timecode
   • Generate Mode: System generates timecode
   • Offset Mode: Applies offset between timecode and internal frames
3. Frame Mapping:
   • Map specific timecode values to specific frames in the move
   • Set timecode start point relative to move start
   • Configure looping behavior with timecode

Practical Applications

• Motion Control VFX: Precisely synchronize multiple passes with identical camera movements
• Live Action Integration: Coordinate camera movement with actor timing and practical effects
• Multi-Camera Setups: Synchronize multiple RTMC130 systems for coordinated shooting
• Animatronics Control: Trigger character movements in sync with camera moves
• Special Effects Timing: Coordinate pyrotechnics, lighting changes, or other effects

Advanced Curve Manipulation

The Graph Editor provides powerful tools for fine-tuning motion curves to achieve precise, cinematic camera movements.

Advanced Curve Types

Beyond the basic curve types (Linear, Spline, Ease), the RTMC130 offers specialized curves for specific effects:

Handle-Based Curve Editing

Fine-tune curves by adjusting tangent handles in the Graph Editor:

1. Access Advanced Handle Controls:
   • In Graph Editor, press H to toggle handle display
   • Select a keyframe to reveal its handles
   • Use arrow keys for fine adjustments
2. Handle Manipulation Techniques:
   • Handle Length: Controls acceleration/deceleration magnitude
   • Handle Angle: Determines direction of curve entry/exit
   • Symmetrical Handles: For smooth transitions (default)
   • Independent Handles: For cusps or abrupt changes in acceleration
3. Common Handle Adjustments:
   • Short incoming handle + long outgoing handle = fast start from rest
   • Long incoming handle + short outgoing handle = gentle stop
   • Equal length handles = smooth passage through point
   • Opposite angle handles = create cusp or direction change

Curve Operations and Transformations

The RTMC130 provides commands for global modifications to curves:

• Scale Curves (sc): Amplify or reduce movement magnitude
  • Example: sc 1 1.5 (scales Track axis movement by 150%)
• Offset Curves (oc): Shift entire curve up or down
  • Example: oc 2 12.0 (adds 12 units to all Lift axis positions)
• Reverse Curves (rc): Flip direction of movement
  • Example: rc 5 (reverses Pan axis movement direction)
• Time Scale (ts): Stretch or compress timing
  • Example: ts 0.5 (doubles the move duration by slowing it to 50%)
• Curve Fit (cf): Change one curve type to another
  • Example: cf 4 s (converts E/W axis curves to Spline)

Velocity and Acceleration Control

Analyze and optimize the dynamic qualities of movements:

1. View Velocity Graphs:
   • In Graph Editor, press V to toggle velocity display
   • Visualize speed throughout the movement
   • Identify problematic acceleration spots
2. View Acceleration Graphs:
   • In Graph Editor, press A to toggle acceleration display
   • Check for abrupt changes that could cause jerky movement
   • Look for acceleration spikes that might stress the hardware
3. Optimize Dynamics:
   • Adjust curves to limit maximum velocities to safe values
   • Smooth acceleration transitions for more natural camera movement
   • Balance smoothness with timing requirements