---
title: kFxPropertyKey_VariesWhenParamsAreStatic
framework: Professional Video Applications
role: symbol
role_heading: Global Variable
platforms: [fxplug 4.0+]
path: professional_video_applications/kfxpropertykey_varieswhenparamsarestatic
---

# kFxPropertyKey_VariesWhenParamsAreStatic

A key that determines whether your rendering varies even when the parameters remain the same.

## Declaration

```swift
var kFxPropertyKey_VariesWhenParamsAreStatic: String { get }
```

## Mentioned in

Building an FxPlug plug-in manually

## Discussion

Discussion The value for this key is a Boolean NSNumber indicating whether this effect changes its rendering even when the parameters don’t change. This can happen if your rendering is based on timing in addition to parameters, for example. Note that this property is only checked once when the filter is applied, so it should go in static properties rather than dynamic properties.

## See Also

### Property Keys

- [kFxPropertyKey_NeedsFullBuffer](professional_video_applications/kfxpropertykey_needsfullbuffer.md)
- [kFxPropertyKey_ChangesOutputSize](professional_video_applications/kfxpropertykey_changesoutputsize.md)
- [kFxPropertyKey_DesiredProcessingColorInfo](professional_video_applications/kfxpropertykey_desiredprocessingcolorinfo.md)