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Selections and Filters

Fillet, chamfer, shell, and color all need you to tell them which edges or faces to target. FluidCAD gives you two ways to do that: direct selection from operations, and filter-based selection.

Direct selection​

When you call extrude(), cut(), or other operations, the returned object lets you pick specific faces and edges:

const e = extrude(30)

fillet(5, e.endEdges())        // top edges
fillet(3, e.startEdges())      // bottom edges
shell(-4, e.endFaces())        // remove top face and hollow
color("blue", e.sideFaces())   // color the sides

You can also select by index when there are multiple faces or edges:

e.sideFaces(0)                 // the first side face
e.sideFaces(2)                 // the third side face

The select function​

For more control, use select() with filters from fluidcad/filters:

import { select } from 'fluidcad/core';
import { edge, face } from 'fluidcad/filters';

select(edge().verticalTo("xy"))
fillet(3)

select() finds all matching geometry in the scene. The next operation (fillet, chamfer, color, etc.) automatically uses that selection.

Edge filters​

Import edge from fluidcad/filters and chain filter methods:

import { edge } from 'fluidcad/filters';

By direction​

edge().verticalTo("xy")        // edges perpendicular to the XY plane
edge().parallelTo("xz")        // edges parallel to the XZ plane

By position​

edge().onPlane("xy", 30)       // edges that lie on the XY plane at height 30
edge().onPlane("yz", 50, true) // edges on YZ plane at offset 50 (approximate match)

By shape​

edge().circle()                // circular edges
edge().arc()                   // arc-shaped edges
edge().line()                  // straight edges

Negation​

edge().notOnPlane("xy", 0)     // edges NOT on the ground plane
edge().notCircle()             // edges that aren't circular

Face filters​

Import face from fluidcad/filters and chain filter methods:

import { face } from 'fluidcad/filters';

By direction​

face().parallelTo("xy")        // faces parallel to the XY plane (top/bottom faces)
face().parallelTo("xz")        // faces parallel to the XZ plane (front/back faces)

By position​

face().onPlane("xy", 30)       // faces on the XY plane at height 30

By shape​

face().circle()                // circular (flat round) faces
face().cylinder()              // cylindrical faces
face().cone()                  // conical faces

Negation​

face().notOnPlane("xy", 0)     // faces NOT on the ground plane
face().notCircle()             // non-circular faces

Using selections​

With fillet and chamfer​

select(edge().onPlane("xy", 30))
fillet(5)                      // fillets the selected edges

select(edge().verticalTo("xy"))
chamfer(2)                     // chamfers vertical edges

With shell​

select(face().onPlane("xy", 30))
shell(-3)                      // removes selected face and hollows the solid

With color​

select(face().circle())
color("red")                   // colors all circular faces red

select(face().parallelTo("xy"))
color("#3498db")               // hex colors work too

Passing directly​

You can also pass filters directly to operations without calling select() first:

fillet(5, e.endEdges())                    // direct from operation
fillet(5, e.sideFaces(face().cylinder()))   // filter within direct selection

Example: selective filleting​

Fillet only the vertical edges of a box, then color the top:

import { sketch, extrude, fillet, select, color } from 'fluidcad/core';
import { rect } from 'fluidcad/core';
import { edge, face } from 'fluidcad/filters';

sketch("xy", () => {
    rect(80, 60).center()
})

const e = extrude(40)

// Round only the vertical edges
select(edge().verticalTo("xy"))
fillet(8)

// Color the top face
select(face().onPlane("xy", 40))
color("steelblue")