Interpolation is a method of calculating character poses in the frames between two keys. Interpolation is necessary for creating fluid, lifelike motions.Cascadeur offers you powerful and convenient tools for working with interpolations.
Interpolation is applied to groups of subsequent frames known as Interpolation Intervals.
An interpolation interval is always limited by two key frames: one marking the beginning of the interval and another at the end of it.
Interpolation interval is created in two steps:
1. Select several frames on the Timeline
2. Choose a type of interpolation from the menu
After this, in-between frames will be generated automatically
Each interval on the Timeline can use a particular type of interpolation
Note how different types of interpolation affect the trajectory of the object
Types of Interpolation
A type of interpolation can be described as a law to calculate poses and positions on an interpolation interval. Key frames set start and end positions, but how the object should move between these positions is defined by the type of interpolation.
Cascadeur supports several types of interpolation:
In-between values are not calculated, animated objects only change their positions and poses in key frames which results in visibly discrete movement (hence the name)
This is the default type of interpolation.
Frames with Step interpolation are colored white on the timeline
Objects move from the strat to the end point (specified by the key frames) with constant speed.
Frames with Linear Interpolation are colored beige on the timeline.
Objects move along a curve defined by their positions in the key frames, accelerating at the beginning of the trajectory and decelerating near the end of it.
When this type of interpolation is selected on multiple intervals, character movements on previous intervals can influence subsequent ones, producing an effect similar to moving by intertia. This can make movements look more lifelike, but in case this effect is not desired, use Bezier viscous interpolation type instead.
Frames with Bezier Interpolation are colored with a light blue shade.
Bezier viscous Interpolation
This type works in the same way as the Bezier interpolation, but previous movements influence subsequent ones to a lesser degree.
This type is used when you edit a character pose on any frame of the interpolation interval aside from the key frames. Interpolation mode in this interval is changed to Fixed (if it wasn’t set to Step beforehand). This way you can adjust poses between key frames without creating additional keys.
Frames with Fixed Interpolation are colored green.
This type of interpolation is used to combine several types of interpolation on one interval.
For eaxample, when several Layers are combined into one, Mixed interpolation is used to preserve all movements on all combined layers.
IK and FK Interpolation
Cascadeur supports both IK (inverse kinematic) and FK (forward kinematic) interpolation, and you can use any of these on any Interval.
To switch between IK and FK, select several frames (an interval) and set Global or Local mode using the button at the top of the timeline
Note: If layers on this interval have different types of interpolation, Mixed mode will be used