sRectangle

sRectangle belongs to Fusion's basic Shape generators. It creates its own vector geometry and the Shape reference explicitly documents that the node has no external inputs, so the correct Flow begins with sRectangle itself rather than MediaIn → sRectangle or another Shape node → sRectangle.

The generator exposes only Shape Output. That stream remains vector Shape data and can feed sGrid, sDuplicate, sBoolean, sMerge, sChangeStyle or sTransform before any rasterization happens.

sRender is the first point where the parametric rectangle becomes an ordinary raster image. Before sRender, dimensions, corners, outline state and Style remain part of the Shape pipeline.

Solid selects filled versus outline presentation. With Solid enabled, the interior is filled with the authored Style color. With Solid disabled, the interior becomes transparent and Border Width defines the visible outline.

Border Width expands or contracts the border. Blackmagic documents that it can also be used while Solid is enabled, although its role is easiest to understand in outline mode where the stroke is the main visible geometry.

Border Style controls how the rectangle sides join at corners. The documented choices are Bevel, Round and Miter: Bevel cuts the corner, Round creates a rounded join, and Miter preserves a pointed join.

When Solid is disabled, the Inspector reveals Cap Style, Position and Length. Their absence from the captured Solid On screenshot is a conditional-UI state and must not be mistaken for absence from the tool.

Cap Style controls the two free ends of an open outline. Flat terminates at the endpoint, Round adds a semicircular end, and Square projects beyond the endpoint. The difference is only visually meaningful when Length is below 1.0.

Position moves the start or gap along the rectangle perimeter. It is not whole-shape translation: Position moves the opening along the outline while X/Y Offset move the entire rectangle in the frame.

Length 1.0 corresponds to a closed outline. Values below 1.0 create an opening, and keyframing Length provides a procedural write-on around the rectangle perimeter.

X Offset and Y Offset position the primitive in normalized image space. The Shape reference describes 0.0 as the centered baseline and uses X Offset 0.5 as the example that places the shape center at the right edge of the frame.

Z Offset [3D] is visible in the captured Resolve 21 Controls. In ordinary 2D motion graphics it is usually kept neutral unless the Shape is deliberately participating in a depth-compatible setup.

Width and Height independently define the horizontal and vertical size. Equal values create a square baseline while unequal values create a regular rectangle or elongated panel.

Corner Radius rounds the primitive parametrically. At 0.0 corners remain sharp; higher values progressively turn a square toward a circle-like silhouette and a wide rectangle toward a pill or capsule.

Corner Radius is not the same control as Border Style. Radius changes the base rectangular path while Border Style changes how the visible border joins at corners. Diagnose them one at a time.

Angle rotates the whole primitive around its center. It is a layout transform of the rectangle geometry and does not move the outline gap along the perimeter.

The captured Controls panel shows Solid On, Border Width 0.0, X/Y/Z Offset 0.0, Width/Height 0.5, Corner Radius 0.0 and Angle 0.0. Those are saved UI values, not a universal factory-default contract for every Resolve build.

The Style tab defines authored Shape color. The capture shows a white color with Red, Green, Blue and Alpha at 1.0, again as evidence of that saved Inspector state rather than a blanket default claim.

The Color swatch and the numeric Red/Green/Blue/Alpha controls are two interfaces to the same authored Style color. Numeric channels are useful when a production template must be reproduced precisely.

Alpha is the alpha component of the authored Style color. Opacity is a separate overall attenuation stage; lowering both at once compounds transparency and makes diagnosis less obvious.

Allow Combining is not a Union/Subtract/Intersect operation. It concerns Shape alpha behavior under downstream self-overlap: with combining enabled, authored alpha is preserved, while disabling it can let overlapping copies accumulate density.

For complex constructions, keep sRectangle focused on the primitive and build downstream: sGrid/sDuplicate for repetition, sBoolean/sMerge for compound silhouettes, sChangeStyle for style overrides and sTransform for object-level motion.

Do not confuse sRectangle with the classic Rectangle Mask simply because the silhouettes look similar. sRectangle outputs Shape data for the Shape system; Rectangle Mask outputs a mask stream used to limit image tools.

For a normal UI card, establish Width/Height first, then Corner Radius, then Style. Add Angle, animation and downstream image effects only after the silhouette is approved so causality remains clear.

For a frame or write-on workflow, use Solid Off, then set Border Width and Border Style, lower Length below 1.0, choose a Cap Style and finally animate Position and Length independently.

Judge thin borders, rounded joins and cap details after sRender at 100% Viewer zoom. Fit-to-view can hide antialiasing and edge differences that matter at delivery resolution.

If the entire finished panel must move or scale as one object with downstream decorations, using sTransform after the generator is often cleaner than mixing object motion into Width/Height/Offset keyframes.

Production QC should include RGB and Alpha Viewer checks, Solid On/Off A/B, Corner Radius zero versus rounded, Length 1 versus below 1, and Allow Combining on intentional overlap so topology, style and raster-edge issues stay separable.