F-Curve Modifiers¶

Reference

Panel: Sidebar region ‣ Modifiers ‣ Modifiers

F-Curve modifiers are similar to object modifiers, in that they add non-destructive effects, that can be adjusted at any time, and layered to create more complex effects. Like object modifiers, F-curve modifiers are evaluated from the top down. In other words, the top modifier is calculated first and consequent modifiers are calculated in order. Modifiers can be moved by dragging the modifier box from the top right.

Modifiers can be muted or hidden by toggling the checkbox in the modifier’s panel header. They can be removed using the delete button in the modifier’s panel header.

Adding a Modifier¶

Modifiers panel.¶

The F-curve modifier panel is located in the Sidebar region. Select a curve by selecting one of its curve points, or by selecting the channel list. Click on the Add Modifier menu to select a modifier.

Types of Modifiers¶

Generator Modifier¶

Generator creates a polynomial function. These are basic mathematical formulas that represent lines, parabolas, and other more complex curves, depending on the values used.

Mode

Method used to represent the equation.

Expanded Polynomial: Equation in the form \(y = x^1 + x^2 + ... + x^n\).
Factorized Polynomial: Equation in the form \(y = (Ax + B)(Cx + D)\).

Additive

This option causes the modifier to be added to the curve, instead of replacing it by default.

Order

Specify the order of the polynomial, or the highest power of X for this polynomial. (Number of coefficients: 1.)

Change the Coefficient values to change the shape of the curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.

Built-in Function Modifier¶

These are additional formulas, each with the same options to control their shape. Consult mathematics reference for more detailed information on each function:

Type

The built-in function to use.

Sine: Sine.
Cosine: Cosine.
Tangent: Tangent.
Square Root: The square root of the value.
Natural Logarithm: The natural log of the value.
Normalized Sine: \(sin(x)/x\).

Additive

This option causes the modifier to be added to the curve, instead of replacing it by default.

Amplitude

Adjusts the Y scaling.

Phase Multiplier

Adjusts the X scaling.

Phase Offset

Adjusts the X offset.

Value Offset

Adjusts the Y offset.

Influence

Controls the percentage of affect the modifier has on the F-curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.

Envelope Modifier¶

Allows you to adjust the overall shape of a curve with control points.

Reference

Set the Y value the envelope is centered around.

Min

Lower distance from Reference Value for 1:1 default influence.

Max

Upper distance from Reference Value for 1:1 default influence.

Add Control Point

Add a set of control points. They will be created at the current frame.

Point

Frame: Set the frame number for the control point.
Min: Specifies the lower control point’s position.
Max: Specifies the upper control point’s position.

Influence

Controls the percentage of affect the modifier has on the F-curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.

Cycles Modifier¶

Cycles allows you add cyclic motion to a curve that has two or more control points. The options can be set for before and after the curve.

Note

The Cycles Modifier can only be the first modifier.

Before/After Mode

No Cycles: Do not repeat curve data before/after.
Repeat Motion: Repeats the curve data, while maintaining their values each cycle.
Repeat with Offset: Repeats the curve data, but offsets the value of the first point to the value of the last point each cycle.
Repeat Mirrored: Each cycle the curve data is flipped across the X axis.

Count

Set the number of times to cycle the data. A value of 0 cycles the data infinitely.

Influence

Controls the percentage of affect the modifier has on the F-curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.

Trivially Cyclic Curves¶

When the Cycle Mode for both ends is set to either Repeat Motion or Repeat with Offset, and no other options of the modifier are changed from their defaults, it defines a simple infinite cycle.

This special case receives some additional support from other areas of Blender:

Automatic Bézier handle placement is aware of the cycle and adjusts to achieve a smooth transition.
The Cycle-Aware Keying option can be enabled to take the cycle into account when inserting new keyframes.

Noise Modifier¶

Modifies the curve with a noise formula. This is useful for creating subtle or extreme randomness to animated movements, like camera shake.

Blend Type

Replace: Adds a -0.5 to 0.5 range noise function to the curve.
Add: Adds a 0 to 1 range noise function to the curve.
Subtract: Subtracts a 0 to 1 range noise function to the curve.
Multiply: Multiplies a 0 to 1 range noise function to the curve.

Scale

Adjust the overall size of the noise. Values further from 0 give less frequent noise.

Strength

Adjusts the Y scaling of the noise function.

Offset

Offsets the noise in time.

Phase

Adjusts the random seed of the noise.

Depth

Adjusts how detailed the noise function is.

Influence

Controls the percentage of affect the modifier has on the F-curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.

Limits Modifier¶

Limit curve values to specified X and Y ranges.

Minimum X, Y: Cuts a curve off at these frames ranges, and sets their minimum value at those points.
Minimum X, Y: Truncates the curve values to a range.
Influence: Controls the percentage of affect the modifier has on the F-curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.

Stepped Interpolation Modifier¶

Gives the curve a stepped appearance by rounding values down within a certain range of frames.

Step Size: Specify the number of frames to hold each frame.
Offset: Reference number of frames before frames get held. Use to get hold for (1-3) vs (5-7) holding patterns.
Start Frame: Restrict modifier to only act before its “end” frame.
End Frame: Restrict modifier to only act after its “start” frame.
Influence: Controls the percentage of affect the modifier has on the F-curve.

Restrict Frame Range¶

Start/End: The frame the modifier’s affect starts/ends.
Blend In, Out: The number of frames, relative the start/end values above, the modifier takes to fade in/out.