In-Place Animation

Technique to temporarily freeze animations for easier scene setup

Node network showing the setup for freezing and restoring animation

Overview

Animation freeze is a powerful technique that allows you to temporarily hold animations or simulations in place while you work on other elements of your scene. This is particularly useful when you need to:

Add elements to a moving scene
Work on character animation relative to moving objects
Make precise adjustments to specific frames
Coordinate multiple animated elements

Common Use Case

For example, when working with a car driving along a road, you might want to:

Freeze the car's motion temporarily
Place and animate a character relative to the frozen car
Restore the car's original animation once complete

Implementation

1. Freeze Animation

Detail Wrangle:

// Compute frame's centroid from bbox
vector bbmin = getbbox_min(0);
vector bbmax = getbbox_max(0);
vector c = (bbmin + bbmax) * 0.5;  // centroid
setdetailattrib(0, "root_t", c, "set");

Point Wrangle:

vector t = detail(0, "root_t");
@P -= t; // remove frame's world translation

2. Restore Animation

Point Wrangle:

vector t = detail(1, "root_t"); // plug original (with the detail attr) into input 2
@P += t;

Aligning Scene Elements

Once you have a frozen animation, you can use it as a reference to freeze and align other parts of your scene. This is particularly useful for elements that need to interact with or follow the main animated object, such as effects, trails, or environmental elements.

Aligning Other Elements

Attribute Wrangle:

// INPUT 1: other parts of scene
// INPUT 2: car stream that has detail "root_t"
vector t = detail(1, "root_t", 0);
@P -= t;    // move INPUT 1 pts into INPUT 2 in-place space

This technique allows you to align any scene element with your frozen animation. For example, you can use it to:

Set up tire trails and track marks
Position emission points for effects like dirt and smoke
Align environmental elements that interact with the animation
Create reference geometry for simulations

Examples

Basic animation freeze workflow demonstration

Using frozen animation to align road geometry for tire trails and effect emission points

See also: Bake Animation and Export as Alembic in Cinema 4D - Learn how to prepare and export character animations as Alembic files that can be used with this freezing technique.