Drop Shadow
Adds a colored, blurred shadow behind the source image, offset by a specified distance.
Category: Effects Menu path: Effects > Drop Shadow
Ports
| Port | Type | Direction | Description |
|---|---|---|---|
in | imageRgba16f | input | Input image |
out | imageRgba16f | output | Image with drop shadow composited behind it |
Parameters
| Param | Type | Default | Description |
|---|---|---|---|
color | color | black (0,0,0,1) | Shadow color in linear space. |
offset | vec2 | (5, 5) | Shadow displacement in pixels (X, Y). Positive X = right, positive Y = down. Keyframeable. |
blur | scalar | 10 | Gaussian blur radius for the shadow softness. 0 = hard shadow. Keyframeable. |
opacity | scalar | 0.75 | Shadow opacity. 0 = invisible, 1 = fully opaque shadow. Keyframeable. |
spread | scalar | 0 | Controls shadow alpha hardening. 0 = soft natural falloff, 1 = hard opaque shadow before blur. Keyframeable. |
Expose Channels
When enabled (E button on node header), adds input ports that override params via edge connections:
| Port | Type | Overrides |
|---|---|---|
offset_in | vec2 | offset |
blur_in | scalar | blur |
opacity_in | scalar | opacity |
spread_in | scalar | spread |
How It Works
The drop shadow is a three-pass operation:
- Shadow pass: The source image's alpha channel is sampled at an offset UV position, then hardened by the spread parameter (
pow(alpha, spread_exp)). The result is tinted with the shadow color and scaled by opacity. - Blur pass: The shadow is gaussian-blurred to create soft edges.
- Merge pass: The original image is composited OVER the shadow using Normal blend mode, so the source appears on top with the shadow behind.
Drop shadow expands content bounds based on offset distance plus blur radius (×3 for the gaussian tail), ensuring the shadow isn't clipped at comp edges.
Usage Examples
Basic: Simple drop shadow
- Add a Drop Shadow node after your content (text, shape, image)
- Set offset to (5, 5), blur to 10, opacity to 0.6
- A soft dark shadow appears behind and below the content
Creative: Long dramatic shadow
- Set offset to (20, 40) for a tall shadow cast by a low light source
- Increase blur to 30 for a diffuse, distant-light feel
- Set spread to 0.5 to keep the shadow dense near the object
Advanced: Colored contact shadow
- Set color to a dark blue and offset to (0, 2)
- Set blur to 3 and spread to 0.8
- Creates a tight, colored contact shadow directly beneath the object
Tips
- Spread 0 gives the most natural soft falloff; spread 1 makes the shadow fully opaque before blur is applied
- Offset is in comp pixels, so the shadow position is resolution-dependent
- Negative offset values cast the shadow upward/leftward
- For text layers, apply Drop Shadow after DrawText for the cleanest result
- Stack multiple Drop Shadow nodes for layered shadow effects (e.g. a tight contact shadow plus a diffuse cast shadow)