Thin line visible just outside recorded window

[nvn01]

Hi, does anyone else have this issue? There is a thin line visible just outside the recorded window in Studio Mode.

I set the shadow to 0 and the border to none, but the line is still visible in the editor and in the exported video. Changing the padding sometimes hides it, but it appears again after I export the video.

I'm using Windows 11.

[linear]

CAP-762

[tembo]

This looks like a rendering bug in the shader pipeline. The issue stems from how border_width defaults to 5.0 even when the border is disabled.

In crates/rendering/src/lib.rs:3633, the display uniforms are constructed with:

border_width: project.background.border.as_ref().map_or(5.0, |b| b.width),

This default value of 5.0 is then used in the shader at crates/rendering/src/shaders/composite-video-frame.wgsl:190:

let edge_padding = max(2.0, uniforms.border_width + 2.0);

When border is set to "none", border_width is still 5.0, resulting in an edge_padding of 7.0 pixels. This padding defines a region just outside the card bounds where the shader can sample and draw, which explains the thin line artifact that persists even with shadow at 0 and border disabled.

The fix would be to change the default from 5.0 to 0.0 when border is None:

border_width: project.background.border.as_ref().map_or(0.0, |b| b.width),

The same pattern appears at line 3576 for frame chrome uniforms. For reference, the camera uniforms at line 3836-3837 already correctly set border_width: 0.0 when there's no border, which is why this artifact doesn't appear on camera overlays.