p5.tree/visibility

Knowing what the camera can see.

Ask whether a point, a sphere or a box is in view before drawing it. visibility() answers VISIBLE, SEMIVISIBLE or INVISIBLE for the current camera; bounds() captures the six planes of another camera's view so the same question can be asked from its point of view; and distanceToBound() measures how far a point is from one of those planes.

Reach for it to skip drawing what is off-screen, or to show what a second camera is looking at.

p5

`visibility(opts)`

Test whether a point, a sphere or an axis-aligned box is inside, crossing or outside the current camera's view frustum, returning VISIBLE, SEMIVISIBLE or INVISIBLE (see the sphere example). Give a point as center, a sphere as center plus radius, and a box as its two corners; mat4Model places local-space bounds in the world (see the AABB example), and bounds tests against another camera's planes from bounds(). Needs a WEBGL canvas.

Parameter	Type	Default	Description
`opts`	`{ corner1?: Float32Array \| ArrayLike \| p5.Vector, corner2?: Float32Array \| ArrayLike \| p5.Vector, center?: Float32Array \| ArrayLike \| p5.Vector, radius?: number, bounds?: object, mat4Model?: Float32Array \| ArrayLike \| p5.Matrix, }`

Returns number p5.Tree.VISIBLE | SEMIVISIBLE | INVISIBLE

Sphere test against the current camera: edge-crossers flagged, culled ones skipped

Local-space AABB under mat4Model

`bounds([opts])`

Compute the six planes of a camera's view frustum as a keyed object — the current camera, or one given as mat4Eye — to pass as the bounds option of visibility() and distanceToBound() (see the second-camera example). Needs a WEBGL canvas.

Parameter	Type	Default	Description
`opts` optional	`{ mat4Eye?: Float32Array \| ArrayLike \| p5.Matrix }`

Returns object

Cull against a second camera's frustum

let scope
const eye = new Float32Array(16)
const proj = new Float32Array(16)

function setup() {
  createCanvas(400, 300, WEBGL)
  camera(350, -250, 650, 0, 0, 0, 0, 1, 0)
  scope = createFramebuffer({ width: 1, height: 1 })
}

function paint(v) {
  if (v === p5.Tree.INVISIBLE) {
    noFill()
    stroke('white')
  } else {
    noStroke()
    fill(v === p5.Tree.VISIBLE ? '#ff4fd8' : 'white')
  }
}

`distanceToBound(point, key, [bounds])`

Signed distance from a point to one frustum plane. Positive → outside (invisible side).

Parameter	Type	Description
`point`	`ArrayLike\|p5.Vector`
`key`	`number\|string`	p5.Tree plane constant (`LEFT`, `RIGHT`, `NEAR`, `FAR`, `TOP`, `BOTTOM`).
`bounds` optional	`object`	Planes from `bounds()`. Defaults to the current camera's view.

Returns number

Signed distance to the RIGHT plane: negative inside, positive outside