sdf.subtract (procNode)

Everything in the first shape that is not in the second: b carved out of a. With blend above 0 the cut is filleted. A shape is a field of position: nothing is evaluated until something reads it, such as sdf.mesh, sdf.sample or field.substitute.

Inputs

• a (Sdf): The shape being cut into. What is left is made of this one.
• b (Sdf): The shape being removed. Everything inside it is carved out of a.
• blend (Float, default 0.0): How wide the fillet where the two shapes meet is, in the shapes' own units. At 0 the two meet at a hard crease. Above 0 their distances bend into each other over a band this wide.
• blend_kind (String, default "polynomial"): Which smooth minimum shapes the fillet, read only when blend is above 0: "polynomial" reaches the plain result exactly at the edge of the band, "exponential" never quite reaches it, "root" is the smoothest and widest reaching, and "chamfer" cuts the corner off with a flat 45-degree facet.

Outputs

• sdf (Sdf): the shape, a record of field (the signed distance at each point of space, negative inside) and bounds ({ min, max }, the box the shape stays inside).

The field is sdf.smooth_max of a and the negated b. The bounds are a's, grown by blend.

Example

local cut = g.sdf.subtract({ a = g.sdf.box({ size = vector.create(1, 1, 1) }), b = g.sdf.sphere({ radius = 0.6 }) })
local mesh = g.sdf.mesh({ sdf = cut, resolution = 16 }).geometry