Roof planner, weight map & tilt test

Roof view & auto-fill panels

The Roof button in the toolbar (or Toggle roof view in the command palette) flips the camera to a true straight-down view of the roof face alone: floor furniture disappears from the drawing (it stays in your build and in every total), the roof panel stays visible, and an amber outline marks the usable rectangle — the dark band along the edges is the rolled shoulder nothing rigid can sit on. Fans, air-con units, rails, roof tents and their cutouts drag around exactly as in 3D.

The Roof planner HUD in the bottom-right corner reads the roof for you: usable length × width and area, the clear area still free once every fan and cutout is subtracted, and the array — placed panels and their watts. That wattage is the same number the Build Sheet's power system reads, so filling the roof updates your autonomy live.

1. Press Roof in the toolbar. Place your roof fan (and anything else that must live up there) first — panels pack around obstacles, so the obstacles come first.
2. In the HUD, pick a Panel preset — a real product from the gear list, or the generic catalog panel — and a Gap in millimetres between frames (25 by default; real mounts want 20–30 mm).
3. Read the preview: Fits N more · +W tells you what the fill will add before you commit. Tick Replace panels if you want existing panels cleared first.
4. Press Auto-fill panels. The engine tries both orientations, packs from both ends of the roof and flush against every obstacle, keeps the layout that fits more panels — and places them as one undo step.

Weight distribution map

The axle numbers in the build stats tell you *whether* the van is loaded well; the weight distribution map shows you *where*. Turn it on under Settings › Scene › Weight distribution map (or Toggle weight map in the command palette) and the cargo floor is cut into a 15 cm grid, each cell tinted from sky blue to amber to red by kilograms per square metre.

The scale is relative to the densest cell of *this* build, so the reddest patch is your heaviest spot, not a fixed limit. Every item's footprint is split across the cells it covers, raised items project straight down onto the floor, and the same exclusions as the payload maths apply — hidden items, the person silhouette and ground-mounted gear don't count. A legend sits in the bottom-right corner while the map is on.

Tilt test

The Tilt test (the mountain icon next to Measure, or the command palette) answers the question every van builder asks on their first alpine hairpin: how far would this build lean before it tips? Entering the test sweeps the van's lean from level to just past its computed tipping angle over a few seconds, then hands you a slider to set the angle yourself. Replay runs the sweep again; X or the close button exits.

The panel reports Tips at N° for the loaded build, the same angle for the empty van, how much of the margin your build costs (or, rarely, gains), and the Static Stability Factor — track width over twice the centre-of-mass height, the figure the industry uses, with a plain-language class beside it. The maths folds in every placed item at its real height, the shell build-up, and your packed gear; the rotation itself is visual only — nothing in your layout moves.