Blur

Apply gaussian, box, directional, radial, or motion blur to images and volumes.

What it does

Blur softens an image or a Volume using one of several algorithms: Gaussian falloff, uniform Box averaging, Directional streaking, Radial zoom, Circular spin, a per-pixel Vector Field flow, temporal Motion Blur, or a Depth of Field pass driven by a depth input. Radius sets the strength in pixels, or in voxels on a Volume. Most modes add their own controls: Angle for Directional, Center for Radial and Circular, Samples and Shutter for Motion Blur, Focus Distance and Focus Range for Depth of Field.

Fed a live 3D object, Blur either stays a live, orbit-able object with the blur applied in screen space (Rasterize off), or collapses to a flat, camera-facing card first (Rasterize on). Wiring a depth input also enables edge-preserving blur through Depth Threshold.

When to use it

ParameterTypeDefault
content_inOneOf([Collection, GpuGeometry, GpuSplats, Field, MorphField, CollectionArray, RasterArray, VolumeArray, FieldArray])
vector_fieldOneOf([FieldOf(Raster), ForceField])
depth_inOneOf([FieldOf(Raster)])
rasterizeBooleanfalse
billboardBooleantrue
cameraOneOf([Camera3D])
blur_typeString"Gaussian"
radiusNumber5
angleNumber0
center_xNumber0.500
center_yNumber0.500
samplesNumber8
shutterNumber1
focus_distanceNumber0.500
focus_rangeNumber0.100
max_blurNumber20
depth_thresholdNumber0
positionVec3(0, 0, 0)
rotationVec3(0, 0, 0)
scaleVec3(1, 1, 1)
anchorVec3(0, 0, 0)
spatial_strengthField
strengthNumber1

Gotchas

Depth Threshold takes effect only once a depth input is wired and the value is above 0. Neighbouring depth values are compared and blending is skipped across edges where the difference exceeds the threshold, which keeps foreground subjects crisp while the background blurs.

Radial, Circular, Motion Blur and Depth of Field each read Radius as their main strength control but scale it differently: zoom amount, spin angle, streak length, maximum defocus. The same Radius value reads as very different amounts of blur between modes.

Switching Blur Type to Vector Field before wiring anything into Vector Field leaves the image passed through unblurred. Connect a flow field first.

Gaussian (IIR) gives visually the same result as Gaussian and stays fast at very large radius values. Use it when pushing Radius high and interaction needs to stay responsive.

Worked example

  1. Add a Blur and wire an image into Content.

  2. Leave Blur Type on Gaussian and raise Radius to the softness you need.

  3. For a motion streak, switch Blur Type to Directional and set Angle to match the direction of movement.

  4. For a camera-style defocus, wire a depth output into Depth In, switch Blur Type to Depth of Field, and adjust Focus Distance and Focus Range until the subject reads sharp and the rest falls away.

  5. If Content is a live 3D object, leave Rasterize off to keep it orbit-able while blurred. Turn Rasterize on for a flat, camera-facing card instead.

See also

Convolve · Sharpen · Displace · Rasters (images)