# F-Curve Modifiers¶

Reference

Panel: |
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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.

## Adding a Modifier¶

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¶

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

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

See also

The Wikipedia Page for more information on polynomials.

### Built-in Function¶

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

- Sine
- Cosine
- Tangent
- Square Root
- Natural Logarithm
- Normalized Sine (
`sin(x)/x`

)

- Amplitude
- Adjusts the Y scaling.
- Phase Multiplier
- Adjusts the X scaling.
- Phase Offset
- Adjusts the X offset.
- Value Offset
- Adjusts the Y offset.

### Envelope¶

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

- Reference Value
- 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 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.

### Cycles¶

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.

- Cycle Mode
- 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.

- Before, After Cycles
- Set the number of times to cycle the data. A value of 0 cycles the data infinitely.

#### 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¶

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.

### Limits¶

Limit curve values to specified X and Y ranges.

- Minimum, Maximum X
- Cuts a curve off at these frames ranges, and sets their minimum value at those points.
- Minimum, Maximum Y
- Truncates the curve values to a range.

### Stepped Interpolation¶

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.
- Use Start Frame
- Restrict modifier to only act before its “end” frame.
- Use End Frame
- Restrict modifier to only act after its “start” frame.