Skip to contents

Hand-drawn ("sketch") rendering

Source: R/grob.R
sketch.Rd

Attach to a grob's sketch argument to render it in a hand-drawn, sketchy style (the Rough.js look): wobbly outlines and hachure fills. Supported by rect_grob(), polygon_grob(), lines_grob(), and circle_grob(). Output is deterministic given seed.

Usage

sketch(
  roughness = 1,
  bowing = 1,
  fill_style = c("hachure", "solid", "crosshatch", "zigzag", "dots"),
  fill_weight = NULL,
  hachure_angle = -41,
  hachure_gap = NULL,
  curve_tightness = 0,
  disable_multi_stroke = FALSE,
  preserve_vertices = FALSE,
  seed = 1L
)

Arguments

roughness

Wobble amount (>= 0; 0 is nearly crisp, 1 the default hand-drawn look, higher is wilder).

bowing

How much straight edges bow (0 disables bowing).

fill_style

One of "hachure" (default), "solid", "crosshatch", "zigzag", "dots". Non-solid styles paint the fill colour as line work.

fill_weight

Stroke width of fill/hachure lines, in lwd units (1 == 1/96 inch); NULL derives it from the grob's lwd.

hachure_angle

Hachure line angle in degrees.

hachure_gap

Gap between hachure lines, in lwd units; NULL = auto.

curve_tightness

Curve fit tightness for round shapes (circles, arcs).

disable_multi_stroke

If TRUE, draw single (not doubled) outline strokes — a cleaner, less sketchy line.

preserve_vertices

If TRUE, keep shape vertices exact (only edges wobble).

seed

Integer seed for the wobble (same seed => identical output).

Value

A vellum_sketch object for a grob's sketch argument.

Details

Sketch is a deliberate exception to vellum's crisp, fidelity-first defaults — see vignette / _docs/DESIGN-ROUGHR.md. Text is never sketched.

Examples

rect_grob(gp = vl_gpar(fill = "steelblue", col = "black"), sketch = sketch())
#> <vellum::grob_rect>
#>  @ name  : NULL
#>  @ gp    : <vellum::vl_gpar>
#>  .. @ col       : chr "black"
#>  .. @ fill      : chr "steelblue"
#>  .. @ lwd       : NULL
#>  .. @ alpha     : NULL
#>  .. @ lty       : NULL
#>  .. @ lineend   : NULL
#>  .. @ linejoin  : NULL
#>  .. @ linemitre : NULL
#>  .. @ fontfamily: NULL
#>  .. @ fontface  : NULL
#>  .. @ fontsize  : NULL
#>  .. @ lineheight: NULL
#>  @ vp    : NULL
#>  @ id    : NULL
#>  @ role  : NULL
#>  @ keys  : NULL
#>  @ meta  : NULL
#>  @ x     : unit [1:1] 0.5npc
#>  @ y     : unit [1:1] 0.5npc
#>  @ width : unit [1:1] 1npc
#>  @ height: unit [1:1] 1npc
#>  @ sketch:List of 10
#>  .. $ roughness           : num 1
#>  .. $ bowing              : num 1
#>  .. $ fill_style          : chr "hachure"
#>  .. $ fill_weight         : num -1
#>  .. $ hachure_angle       : num -41
#>  .. $ hachure_gap         : num -1
#>  .. $ curve_tightness     : num 0
#>  .. $ disable_multi_stroke: logi FALSE
#>  .. $ preserve_vertices   : logi FALSE
#>  .. $ seed                : num 1
#>  .. - attr(*, "class")= chr "vellum_sketch"