The Tiling design dialog

The dialog has the chart on top with the proposed tile line, four parameter cards below, a stats strip, and an Apply Design button.

Three design modes

Like the Ditching designer, the Tile design dialog has three modes, chosen with the tabs near the top:

• Best Fit — automatic. The optimizer finds the smoothest tile line that stays inside your depth window and at or above Min Grade. This is the default and usually correct.
• Guided — tap terrain points on the chart to pin the tile line through them. Tap a pinned point again to un-pin it. Between your pins the app holds Min Grade. A hint reads Tap terrain points to add vertices.
• Freeform — tap anywhere to add a vertex, tap an interior vertex to delete it, or drag a vertex to move it. The two end points stay put. A hint reads Tap to add/remove, drag to move. Freeform has no automatic grade rules, so the app still warns you if the line runs uphill or falls below Min Grade.

In Guided and Freeform, an Undo button at the top of the tab row steps back your last change. The Reverse outlet toggle is hidden in Freeform, since you place the line yourself.

Parameter cards (tap-to-edit on every value):

• TARGET DEPTH — the ideal depth below the surface for the tile. Default 36″ (3.00 ft in Decimal Feet mode — same stored depth). The optimizer aims for this depth as long as Min Depth and Min Grade allow it.
• MIN DEPTH — the absolute shallowest the tile is allowed to be. Default 24″ (2.00 ft). Frost line and minimum burial requirement. The design line will not come closer than this to the surface.
• MAX DEPTH — the absolute deepest the tile can be. Default 72″ (6.00 ft). Equipment / soil limit. The design line will not go deeper than this below the surface.
• MIN GRADE — minimum drainage grade. Default 0.10%. The design line will never be flatter than this anywhere.

The chart

• Brown/grey line on top is the surveyed surface.
• The proposed tile line renders as a white-bordered dark line, drawn thicker than the terrain line so it reads like a pipe. The stroke is solid, not dashed.
• Min Depth is a dashed green line; Max Depth is a dashed magenta line. Where the tile rises above Min Depth (not enough cover) the chart shades that stretch amber; where it drops below Max Depth (too deep) it shades red. A clean design shows no shading between the two lines.
• If the design can't satisfy all constraints, the line goes as close as it can and a warning shows (see below).

Violation warnings

If a design can't satisfy every constraint, a red warning ribbon appears below the chart naming the problem and roughly where it is — for example Tile shallower than minimum depth near 4+50, Tile deeper than maximum depth near 7+00, or (in Freeform) Tile line runs uphill near 3+20 or Grade below minimum near 5+10. The matching stretch is shaded amber or red on the chart. The design is still drawn and Apply Design still works — the warning is telling you to verify that stretch before you trench, not blocking you.

Outlet detection

The dialog automatically figures out which end is the outlet (lower elevation = outlet). If you see the design going the wrong way, tap the Outlet toggle in the dialog header to flip it.

Stats strip

Left to right, the strip carries a Design label and these readouts:

• Grade — overall grade of the proposed tile, percent.
• Max Depth — the deepest the design actually goes below the surface (the engine's worst case, not your Max Depth setting).
• Length — total tile length.
• Inlet Depth — design depth below terrain at the upstream inlet.
• Required Start Depth (at outlet) — the headline number, pulled hard-right in a blue badge; this is the depth your trencher has to hit when you start at the outlet end.

When the chart and numbers look right, tap Apply Design. The app saves the design (named with the workflow label and timestamp), opens the Grade screen, and prompts for benchmark calibration.