Configuration Sliding Curtain

Sliding Curtain

A cover type for a horizontally sliding curtain — fabric that draws sideways across the window opening, either as a single panel from one edge or as two leaves parting from the centre. The integration decides how far to draw the curtain to keep direct sun off the window (or off a target floor area) while leaving the rest of the opening clear for daylight, and drives that through the cover's position.

Choose Sliding curtain (horizontal) in the cover-type picker when you add or reconfigure an instance.

A sliding curtain is a position-axis cover, like a vertical blind: 0% = closed (fabric fully drawn across the window, blocking the sun) and 100% = open (fully retracted). One or two bound cover entities both receive the same target, so a single-slide panel and a bi-parting pair are configured identically.

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Two ways to run it

The type has a simple default and an optional geometric mode. You pick between them with the Use a shade area toggle on the geometry screen.

• Binary (default — toggle off). The curtain draws fully across whenever direct sun reaches the window (the sun is inside the sun acceptance angle, above the elevation limit, and outside the sunset window) and retracts fully otherwise. This needs no measurements beyond the usual azimuth and sun acceptance angle, and works on open/close-only hardware — it only ever commands the two endpoints. This is the "simple logic" most curtain setups want.

• Shade-area percentage (toggle on). You define a floor shade area from two points and tell the integration which way the curtain slides. It then closes the curtain only as far as needed to keep that area out of direct sun — a continuous percentage rather than all-or-nothing. This needs a cover that reports set_cover_position; if none of the bound covers support it, the integration warns during setup and only open/close is issued.

If the toggle is off, none of the shade-area fields below have any effect, so an existing binary curtain is unaffected by an upgrade.

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Geometry options

Alongside the standard Azimuth and sun acceptance angle angles on the Sun Tracking screen, the sliding curtain adds:

Setting	Range	Default	Meaning
Use a shade area (continuous coverage)	on / off	off	Master toggle. Off = binary open/close. On = the two-point percentage model below.
Window Width	0.1–50 m	—	The width of the opening the curtain covers. Required for the percentage model; unused in binary mode.
Slide Direction	Centre-parting / Single (left) / Single (right)	Centre-parting	How the fabric draws across. Centre-parting = two leaves meet in the middle. Single (left) = one panel anchored at the left edge, closing rightward. Single (right) = one panel anchored at the right edge, closing leftward.
Shade Point 1 — Along Wall (X)	−25–25 m	0 m	Along-wall position of the first shade-area point, from the window centre (0), positive to the right facing the window from inside.
Shade Point 1 — Into Room (Y)	0–50 m	0 m	Depth of the first point into the room, from the window plane (must be > 0).
Shade Point 2 — Along Wall (X)	−25–25 m	0 m	Along-wall position of the second point (same frame as point 1).
Shade Point 2 — Into Room (Y)	0–50 m	0 m	Depth of the second point into the room (must be > 0).

The two shade points use the same coordinate frame as glare zones: X runs along the wall (0 at the window centre, positive to the right when you face the window from inside) and Y is the distance straight into the room. Pick the two corners of the floor area you want kept in shadow — a sofa, a desk, a rug — and the integration keeps direct sun off the strip between them.

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How the shade-area model works

With a shade area configured, the engine takes the sun's current horizontal direction and traces, for each of the two points, the ray that would light it — then finds where that ray crosses the window plane. Those two crossings bound an interval along the window width: the slice of the opening the sun is coming through to reach your shade area. (This is the same ray-to-window-plane projection the glare-zone floor protection uses.)

The slide direction then decides how much curtain that interval costs:

• Single (left) draws from the left edge, so it must reach the interval's right extent.
• Single (right) draws from the right edge, so it must reach the interval's left extent.
• Centre-parting closes from both edges toward the middle; each leaf travels half the distance, and an interval that straddles the centre closes the curtain fully.

The curtain is commanded to the smallest close that covers the interval — no more — so daylight keeps coming through the uncovered part of the window. When the sun is outside the sun acceptance angle, below the elevation limit, inside the sunset window, or its interval falls entirely off the opening, the curtain opens fully.

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What it supports

Capability	Sliding curtain
Binary full open/close on direct sun	✅
Continuous shade-area percentage close	✅ (toggle on)
Single-slide and centre-parting hardware	✅
One or two bound cover entities	✅
Return to default when disabled	✅
Open/close-only hardware	✅ (binary mode)
Tilt / slat angle	❌ — position-only
Glare zones	❌

The full decision pipeline — weather safety, manual override, motion, climate, custom positions, and defaults — applies unchanged, since the curtain flows through the standard position axis.

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Tips

• Start binary. Leave Use a shade area off unless you specifically want to shade a particular spot on the floor — the binary mode needs no measurements and works on any cover.
• Two devices, one instance. For a bi-parting pair driven by two motors, bind both cover entities to the one instance and set Slide Direction to Centre-parting; they receive the same target and move together.
• Measure the shade area like a glare zone. The X/Y frame is identical, so if you have already set up glare zones you can reuse those measurements for the two curtain points.
• The percentage model needs set_cover_position. Open/close-only curtains can't take a partial target, so they fall back to full open/close even with a shade area configured — the setup warning tells you when that applies.

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Related

• Cover Types — the full cover-type comparison
• Vertical — the position-axis blind this type shares its open/closed convention with
• Glare Zones — the floor-coordinate frame and ray projection the shade area reuses
• Sun Tracking — azimuth, sun acceptance angle, and elevation limits
• Diagnostic Sensors — the solar_calculation trace exposes the covered-interval and percentage intermediates