Measured from the building's true geometric center on the floor (not magnetic north). Positive North offset means the mount is closer to the North wall.
Most buildings are a simple rectangle — the width/length above cover that. Non-rectangular buildings (angled corners, an extension, an irregular footprint) can be described directly as up to 6 walls, each its own distance and angle from center.
The roof rolls off past one wall and parks there — that parked structure is its own obstruction, not just an open gap.
Mount type changes the OTA's swing in the 3D preview and how pier side affects it. Doesn't change the wall/roof obstruction math itself — that's driven purely by true Alt/Az.
Each telescope is on its own independent mount. The position entered in Step 1 drives the live pointing preview only. For swing clearance, each telescope uses its own position defined here — including Telescope 1. See the Swing Clearance panel below.
Mount type and OTA dimensions come from Step 3 above. The Step 1 N/S, E/W, and height fields separately drive the live pointing preview and 3D scene.
Click anywhere inside the building to place a telescope pier. Drag to reposition. Enable additional telescopes first — each enabled pier appears on the plan. The number fields below stay in sync and can be used for fine-tuning after placement.
Click inside the building outline to place. Drag to fine-tune position. Use the number fields in the Telescopes card below for precise entry.
Sweeps a grid across the whole sky and checks whether each point clears the walls, the parked roof, and your local horizon — not a dome shutter, since a roll-off roof either fully opens or fully closes.
Center = zenith, edge = horizon, up = North, right = East. The outer boundary traces your building's actual wall shape — a 4-wall rectangle shows as a rectangle, a 6-wall polygon shows its true footprint. Updates live as you change your setup.
● Green — clear of walls, roof, and horizon
● Red — blocked by a wall or the parked roof
● Brown — below your local (terrain) horizon
Terrain beyond the building — trees, other structures. Layered on top of the wall/roof obstruction; whichever blocks more at a given azimuth wins.
Drives the live obstruction calculation, 3D preview, and sky coverage sweep. Select which telescope you are pointing.
Drag to orbit, scroll to zoom.