Corner radius

Corner radius rounds the corners of a picture, which is handy for a picture-in-picture or a screen recording sitting on a background.

Where: Clip tab ▸ Picture ▸ Corner Radius ▸ Radius
Agent tools: set_video

Round the corners

Select a video clip, image clip or freeze frame and open the Picture tab.
Open the Corner Radius section.
Drag Radius, type a value, or click the chevron for a quick pick.

Row	What it does	Default	Range	Quick picks
Radius	How round the corners are, in source pixels	0 px	0 to 500 px	0, 4, 8, 16, 32, 64

Each change is one undo step. Closed, the section’s summary reads the radius, such as 32 px. Reset appears in its header while the radius isn’t 0.

How the radius is measured

The radius is in the source’s own pixels, so it scales with the clip. A radius of 32 px on a clip at 50 % looks like 16 px on the canvas.

It rounds the cropped picture, so the curve follows the crop rather than the original frame. A shadow follows the rounded shape.

A radius can’t be more than half the picture’s shorter side, and anything above that draws as that half. So a big enough radius turns a wide picture into a pill and a square picture into a circle. Radius stops at 500 px, so it gets there only when the picture’s shorter side, after any crop, is 1,000 px or less.

Animate the radius

With an action selected, Radius sets the action’s end state, and the corners ramp there along the action’s curve. See Set what an action animates to.

Good to know

Only video clips, image clips and freeze frames have this section. A rectangle shape has its own radius: see Shape fill, stroke and size.

With an agent

set_video sets this with corner_radius, in source pixels. It takes any value of 0 or more, without the inspector’s 500 px stop. See Tools: picture and grade.