sdf.Difference

sdf.Difference(*sdfs, smoothness=0.1)

Difference of SDFs (subtract all subsequent from first).

Uses smooth maximum for differentiable blending.

Parameters

Name	Type	Description	Default
sdfs		Tuple of SDFs; first is the base, rest are subtracted	()
smoothness	float	Blend half-width in model units, not a fillet radius. 0 is a sharp boolean; the default of 0.1 blends, so a plain Difference(a, b) is a blended one and a caller who wants the sharp operation has to ask for smoothness=0. The value does not scale with the part: 0.1 is a tenth of a unit whatever the unit stands for, enough on a large part to erase a thin internal feature. See :mod:cadjoint.sdf.boolean.smooth for what the blend costs — it moves the field by up to smoothness per operation, and by the full amount wherever the operands agree.	0.1

Methods

Name	Description
material_at	The body’s material, tinted by each tool near the surface that tool cut.
patch_fields	Body patches then tool patches, operand-major, for a sharp cut only.
sdf	Pure function for difference operation.

material_at

sdf.Difference.material_at(p)

The body’s material, tinted by each tool near the surface that tool cut.

Folds over every tool, the way :meth:Union.material_at folds over every operand, so a part cut by more than one tool takes its material from every cut, not just the first.

patch_fields

sdf.Difference.patch_fields()

Body patches then tool patches, operand-major, for a sharp cut only.

max(body, -tool_1, -tool_2, ...), so the result’s surface is the body’s surface where no tool reaches plus each tool’s surface where it cut into the body — pieces of the operands’ surfaces and nothing else. The fields are theirs concatenated in operand order, with every tool negated, exactly as the composition negates it: a tool’s own field reads positive outside the tool, which is inside the cavity it left, so leaving it alone would hand the consumer a patch whose normal points into the material. Negating flips it to positive outside the result, and leaves the zero set — hence argmin |f_i| ownership — untouched.

See :func:~cadjoint.sdf.boolean.base._operand_patch_fields for the order’s guarantees and why a smoothness > 0 difference declines.

sdf

sdf.Difference.sdf(child_sdfs, p, smoothness)

Pure function for difference operation.

Parameters

Name	Type	Description	Default
child_sdfs		Tuple of SDF functions; first is base, rest are subtracted	required
p	Array	Query point(s)	required
smoothness	float	Blend radius	required

Returns

Name	Type	Description
	Array	Difference SDF value