IesProfile

A fixture's measured intensity, as a grid over vertical and horizontal angles.

interface IesProfile

import type { IesProfile } from '@driftengine/assets';

In depth

Candela rather than a normalised curve, because the two answer different questions and only one of them is in the file: the shape of the distribution is what a renderer samples, and the absolute output is what tells a consumer whether this fixture is a reading lamp or a floodlight. Normalising here would throw the second away, and a consumer that wants the shape can divide by maxCandela — which is why it is carried rather than left to be recomputed.

Properties

Name	Type	Description
`verticalAngles`readonly	`Float32Array`	Vertical angles in degrees, increasing. 0 is straight down for the common type-C fixture. More Not resampled to a regular grid here. A real file is dense where the distribution changes and sparse where it does not, and flattening that is a decision about a texture rather than about a file — `iesProfile.ts` in the renderer makes it.
`horizontalAngles`readonly	`Float32Array`	Horizontal angles in degrees, increasing. A single 0 means the fixture is axially symmetric.
`candela`readonly	`Float32Array`	Candela, horizontal-major: all vertical angles of the first plane, then the second.
`maxCandela`readonly	`number`	The brightest value in the grid, so a consumer can normalise without walking it again.