projection

The Projection tool draws a curved path using three anchors: a start/center and two arc points that shape the curve. It’s perfect for sketching “what-if” paths (rounded dips, soft recoveries, tops) without copying past bars—great for illustrating scenarios while you backtest.

Syntax (one line)

projection(originPoint, leftArcPoint, rightArcPoint, styles?)

Parameters

originPoint (PricedData) · Center/start of the projected curve (time & price). leftArcPoint (PricedData) · Controls curvature/extent on the left side. rightArcPoint (PricedData) · Controls curvature/extent on the right side. styles (ProjectionLineToolOverrides) · Visual options for the curve and optional fill.

• color1 (string) · Primary color for the projection line or gradient start.

• color2 (string) · Secondary color for gradient or shading.

• fillBackground (boolean) · Fill the area under/around the curve.

• level1 (LinesLevels) · Per-level line look (e.g., linewidth, linestyle, color, visible).

• linewidth (number) · Thickness of the projection line.

• showCoeffs (boolean) · Show coefficient values if the style supports them.

• transparency (number) · Background transparency for the fill (0–100).

• trendline (object) · Base trendline styling inside the projection. · color (string) · Color of the trendline. · linestyle (number) · Line style (0=solid, 1=dotted, 2=dashed…). · visible (boolean) · Toggle trendline visibility.

Return Value

(string) · The drawing ID of the created Projection.

Example

What this does: Every 48 candles, we draw a gentle “U-shaped” projection from an older pivot, using two arc points to suggest a dip and recovery. All visuals live in one const style that follows ProjectionLineToolOverrides.

//@version=1
init = () => {
  indicator({ onMainPanel: true, format: 'inherit' });
};

onTick = () => {
  // Draw occasionally so the chart stays clean
  if (index % 48 === 0) { // ← change 48 for more/less frequency
    // 1) Choose three anchors to shape the curve
    const origin = newPoint(time(70), closeC(70)); // center/start
    const left   = newPoint(time(52), low(52));    // left arc control
    const right  = newPoint(time(28), high(28));   // right arc control

    // 2) Style (ProjectionLineToolOverrides)
    const style = {
      color1: '#FF8C00',          // primary color (dark orange)
      color2: '#FFA500',          // secondary (lighter orange)
      fillBackground: true,       // soft shading under curve
      transparency: 85,           // 0=opaque, 100=transparent
      linewidth: 2,               // line thickness
      showCoeffs: false,          // keep labels off for a clean look
      trendline: { color: '#FF8C00', linestyle: 2, visible: true }, // dashed guide
      level1: {                    // default per-level line look
        linewidth: 2,
        linestyle: 2,
        color: '#FF8C00',
        visible: true
      }
    };

    // 3) Build the projection
    projection(origin, left, right, style);
  }
};

Tips

• Use meaningful pivots for arc points so the curve “hugs” real structure rather than slicing randomly.

• Keep projection lines subtle (thin/dashed) so they’re clearly distinct from actual price.

• Combine with channels or bands to show where the scenario might meet support/resistance.

Warning

• Don’t pass raw time() or price values—always build anchors with newPoint(time(offset), priceValue) or the drawing can fail.

Good Practice

• Centralize visuals in a single const style so you can reuse and tweak consistently across tests.

• Save a few presets (e.g., orange dashed for “scenario”, gray dotted for “alt scenario”) to keep charts readable.