Blur
Softens an image with one of eight blur types, with an optional Strength map that sets how much each pixel blurs.
Wire the picture into Image. An optional Mask says where the blur shows, and an optional Strength map says how much each pixel blurs, so one node can be sharp in one place and soft in another. Blur takes a texture set too.
The types
Section titled “The types”Type picks the blur, and the rows below it change to match.
| Type | What it does | Its amount |
|---|---|---|
| Gaussian (default) | A smooth, all-purpose blur | Radius |
| Box | A plain average over a square | Radius |
| Median | The middle value of the neighborhood, which removes specks and keeps edges | Radius |
| Motion | A directional streak | Distance, along Angle |
| Bilateral | Smooths flat areas while keeping edges | Diameter and Spread |
| Edge Preserve | A painterly, cel-shaded smoothing | Smoothness |
| Radial | A spin around a center | Spin Angle |
| Zoom | A burst toward or away from a center | Zoom Amount |
Radius is how far the blur reaches, in pixels or in percent of the shorter side. Reach for Median or Bilateral to remove noise without softening edges. Blur Alpha (off by default) keeps sharp transparency edges; turn it on to blur the alpha with the color.
Radial and Zoom draw a handle at their center on the Preview while the node is selected: drag it to move the center (Center X and Center Y), hold Shift to keep to one axis, hold Ctrl to snap to the middle, edges, and thirds of the picture, and double-click it to recenter. The arrow keys nudge it too. Radial also draws an arc above the center whose width is Spin Angle: drag either end around the circle to widen or narrow the spin, hold Shift to snap it to steps of 15 degrees, and double-click an end to reset it. See Canvas handles.
Strength: how much each pixel blurs
Section titled “Strength: how much each pixel blurs”The Strength input takes a grayscale map. Black stays sharp, white blurs by the full amount, and gray blurs part of the way. It scales the type’s own amount (Radius, Distance, Spin Angle, Zoom Amount, Diameter and Spread, or Smoothness) pixel by pixel, on all eight types, so a gradient from black to white becomes a blur that grows smoothly across the picture. With nothing wired, the node blurs evenly as before.
- Strength is not a Mask. A Mask cross-fades a blurred copy over the sharp picture, so halfway along a soft mask edge you see the two on top of each other, which ghosts. Strength changes the blur itself: at gray, each pixel gets a genuinely smaller blur. Use Strength to decide how much each place blurs and Mask to decide where the blur shows at all. They work together.
- On Gaussian, Box, Median, Bilateral, and Edge Preserve, each pixel’s own value sets how blurry that spot is.
- On Motion, Radial, and Zoom, Strength marks what moves. Each pixel’s value sets how much of it moves and how far its color is smeared along its streak, as a solid smear over the pixels around it. Feed in a mask of a runner and the runner smears across the background behind it, while the background itself stays sharp.
- Strength is read as data, the brightness of its stored values with no color conversion, and a map of another size is stretched to the picture.
More ways to use it:
- Zoom burst. A radial Gradient, black at the center and white at the rim, on Strength with Type set to Zoom. The center holds still and the edges burst outward.
- A moving subject. A mask of the subject on Strength with Type set to Motion: the subject streaks over whatever lies behind it. Add Fade so the streak trails off.
- Depth of field from a map. Any depth-like map on Strength gives a Gaussian blur that grows with it. For a lens-accurate blur with bokeh, use Lens Blur.
Streak: Motion one way or both
Section titled “Streak: Motion one way or both”Streak appears for Motion, after Distance.
- Both Ways (the default) smears Distance to each side of every pixel, the classic motion blur. While the node is selected, a line through the center of the Preview shows the streak, with a handle at each end.
- One Way trails the picture toward Angle, with Distance the full length of the trail. An arrow from the center of the Preview shows which way the trail runs and how far.
Drag the tip of the arrow, or either end of the line, to set Angle and Distance together; hold Shift to snap the angle to steps of 15 degrees. Angle uses the screen axis: 0 points right and 90 points down.
One Way with a Strength map gives every streak its own length: speed lines, light trails, or rain whose drops each leave a trail of their own. Wire a cell Noise into Strength and every spot streaks by the gray of its own cell. For drops that run down glass, see Drips.
Fade and Opacity
Section titled “Fade and Opacity”Fade and Opacity appear for Motion, Radial, and Zoom. Each runs from 0 to 100, and both work with or without a Strength map.
- Fade at 100, where a new Blur starts, makes each streak solid near where it starts and fades it out to nothing at its end. At 0 a streak is even along its whole length. Documents saved before Fade existed keep Fade 0, so they look as they did.
- Opacity at 100 (the default) lays the smear solidly over what lies under it. Lower it and the picture underneath shows through.
Edge Mode: tiling textures stay tiling
Section titled “Edge Mode: tiling textures stay tiling”Edge Mode says what the blur reads past the border, on every type except Radial and Zoom.
- Mirror reflects the picture at the border. New Blur nodes start here.
- Clamp repeats the edge pixel.
- Repeat wraps to the opposite edge. Use it on a tiling texture: the blur reads across the seam from the other side, so the result still tiles with no seam.
Documents saved before Edge Mode existed keep the border they always had, Clamp for Median and Mirror for the others, and the row shows it.
Texture sets
Section titled “Texture sets”Blur runs over every map of a set or a library with the same settings, and the Normal stays a unit direction. Every map reads the same Strength map, so the Base Color, Normal, and Roughness stay in register, and Edge Mode set to Repeat keeps a tiling set tiling. The set’s Opacity is blurred only with Blur Alpha on, so a cutout keeps its sharp edge by default.
For a blur that follows the slope of a map rather than one direction, see Slope Blur.
- With GPU Acceleration on, Motion, Radial, and Zoom run on the graphics card for pictures up to 8192 x 8192 whenever they use a Strength map, a Fade above 0, an Opacity below 100, or Motion set to One Way. The processor gives the same result.
- Median, Edge Preserve, Motion, Radial, and Zoom fill the bar on the node during a long cook; see Long cooks show their progress.
Parameters
Section titled “Parameters”Pins
Filter
How far the blur reaches. 0 = no blur, higher = more blur
Also blur the alpha channel. Uncheck to preserve sharp transparency edges
Direction of motion blur in degrees. 0 = right, 90 = down
Motion streak length. Higher = longer motion trail
- Both Ways: the streak runs Distance to each side of every pixel.
- One Way: the picture trails toward Angle, Distance in all. An arrow on the canvas shows the way.
How quickly a streak fades out along its length. 0 keeps it even; 100 fades it to nothing at its end
How solid the smear is. 100 covers what lies under it; lower lets it show through
Neighborhood diameter. Smaller = faster, less smoothing
How similar colors must be to blur together. Higher = more tolerant of color differences
How far the smoothing reaches. Higher = wider area smoothed
Recursive: faster. Normalized Convolution: smoother results
How much the image is smoothed. Higher = larger smoothing area
How much detail is flattened. Lower = more detail preserved. Higher = more cell-shaded look
Horizontal blur center. 0% = left edge, 50% = middle, 100% = right edge
Vertical blur center. 0% = top edge, 50% = middle, 100% = bottom edge
Total rotation arc to smear over, in degrees. 0 = no blur, 180 = half-rotation smear
Strength of the radial smear. 0 = no blur, 100 = maximum streak length
What the blur reads past the border.
- Mirror: reflects the picture at the border.
- Clamp: repeats the edge pixel.
- Repeat: wraps to the opposite edge, so a tiling texture stays tiling.
Mask
How the connected color image is read as a mask
How the mask is sized when it doesn't match the image
Usage Tips
Section titled “Usage Tips”- Bilateral suits skin smoothing: it removes noise while keeping edge detail.
- A small Gaussian blur (Radius 1 to 3) before Edge Detect gives cleaner edges.
- Motion with a long Distance and Streak set to One Way makes speed lines; add a Strength map so each line gets its own length.
- Radial with a small Spin Angle adds gentle camera shake; large angles make a vortex around the center.
- Zoom suits hyperspace, speed, and focal-point emphasis. Set Center X or Center Y to 0 or 100 to zoom from the image’s edge.
- Set Edge Mode to Repeat before blurring a tiling texture.
- Leave Blur Alpha off (the default) on game sprites to keep crisp silhouettes.