# VectorBlur2

> VectorBlur: motion blur along motion vectors — every pixel is smeared along its u / v vector (uv channels) times motion amount (0.5), over the shutter set by motion offset (-0.5 centres it).

VectorBlur: motion blur along motion vectors — every pixel is smeared along its u / v vector (uv channels) times motion amount (0.5), over the shutter set by motion offset (-0.5 centres it). Uniform or gaussian blur type; motion falloff (0.33) softens the ends. The vectors can be offset, inverted, un-premultiplied (uv alpha) or blurred first. Output uvs shows the prepared vectors. Use it after AIVectorGenerator, MotionBlur2D or a render with motion vectors.

| Node | VectorBlur2 |
|---|---|
| Menu | Filter › VectorBlur2 |
| **Names in each format** | |
| .oink comp (JSON) | `"type": "OC_N_vectorblur2"` |
| .nk script | `VectorBlur2` ([how .nk import works](/docs/nuke-users/nk-import)) |
| Python | `nuke.createNode("VectorBlur2")` |
| Assistant (MCP) | `create_node(type="VectorBlur2")` |
| Tab search | `vectorblur2`, or its initials `vb2` |

![VectorBlur2 properties](/shots/nodes/vectorblur2@2x.webp)

## Inputs and outputs

| Port | Name | Type |
|---|---|---|
| input 0 | Source | image |
| input 1 | mask | image |
| output 0 | Image | image |

## Knobs

Panel tab **VectorBlur**, in panel order.

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `channels` | channels | menu | `rgba` | rgba, rgb, alpha, all, none |  | Layer the op applies to: rgb, rgba, alpha, all, none, <layer> or <layer>.<ch> |
| `useGPUIfAvailable` | Use GPU if available | bool | `true` |  | `useGPUIfAvailable` |  |
| `uv` | uv channels | text | `none` |  | `uv` | Layer holding the u, v vectors (px per frame), e.g. motion / forward |
| `mv_presets` | mv presets | menu | `Nuke ScanlineRender` | Nuke ScanlineRender, PRMan, V-Ray Velocity Clamped, V-Ray Velocity, Arnold | `mv_presets` |  |
| `output` | output | menu | `result` | result, uvs | `output` |  |
| `blur_uv` | blur uv | menu | `none` | none, uniform, linear | `blur_uv` |  |
| `invert_uv` | invert uv | bool | `false` |  | `invert_uv` |  |
| `uv_offset` | uv offset | float | `0` | -1 to 1 | `uv_offset` |  |
| `uv_alpha` | uv alpha | text | `none` |  | `alpha` | The channel premultiplied vectors were multiplied by (none = off) |
| `blur_type` | blur type | menu | `gaussian` | uniform, gaussian | `blur_type` |  |
| `scale` | motion amount | float | `0.5` | 0 to 4 | `scale` |  |
| `motion_falloff` | motion falloff | float | `0.33` | 0 to 1 | `motion_falloff` |  |
| `offset` | motion offset | float | `-0.5` | -1 to 1 | `offset` |  |
| `grow_bbox` | expand blur bbox | float | `0` | 0 to 500 (integer) | `grow_bbox` |  |
| `soft_lines` | soft lines | bool | `false` |  | `soft_lines` |  |
| `blur_inside` | blur inside | bool | `true` |  | `blur_inside` |  |
| `normalize` | normalize | bool | `true` |  | `normalize` |  |
| `mask_channel` | mask | menu | `none` | none, rgba.alpha, rgba.red, rgba.green, rgba.blue |  | Mask channel, e.g. rgba.alpha (none = no mask) |
| `inject` | inject | bool | `false` |  |  | Copy the mask into mask.a for nodes downstream |
| `invert_mask` | invert | bool | `false` |  | `invert_mask` |  |
| `fringe` | fringe | bool | `false` |  |  | Only apply the effect at the edges of the mask |
| `mix` | mix | float | `1` | 0 to 1 | `mix` |  |

### Other knobs (Python, .nk and the assistant; not on the panel)

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `gl_color` | Viewer Controls Color | float ×3 | `0, 0, 0` | 0 to 1 |  |  |
| `postage_stamp_frame` | Static Frame | int | `1` | -2147483648 to 2147483647 |  |  |
| `lifetimeStart` | Lifetime Start | int | `0` | -2147483648 to 2147483647 |  |  |
| `lifetimeEnd` | Lifetime End | int | `100` | -2147483648 to 2147483647 |  |  |
| `useLifetime` | Use Lifetime | boolean | `false` |  |  |  |
| `cached` | Cached | boolean | `false` |  |  |  |
| `bookmark` | Bookmark | boolean | `false` |  |  |  |
| `dope_sheet` | Dope Sheet | boolean | `false` |  |  |  |
| `clone_group` | Clone Group | string |  |  |  |  |
| `link_source` | Link Source | string |  |  |  |  |
| `link_overrides` | Link Overrides | string |  |  |  |  |
| `split_views` | Split Views | string |  |  |  |  |
| `unpremult` | (Un)premult by | enum | `none` | none, rgba.alpha |  |  |
| `invert_unpremult` | invert | boolean | `false` |  |  | (Un)premultiply by 1 - alpha |
| `v_up` | V Up (Nuke) | boolean | `true` |  |  |  |

## Knob names in .nk scripts

| .nk knob | Knob here |
|---|---|
| `alpha` | `uv_alpha` |

Other .nk knobs use the same name here. See [.nk import](/docs/nuke-users/nk-import).


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Sources: opencomp_core/nodes/filter/motion_nodes.py, opencomp_electron/src/components/properties/knobSchema.ts, opencomp_core/nodes/help/vectorblur2.md, opencomp_core/nk/mapping.py