TS2339: Property 'array' does not exist on type 'BufferAttribute | InterleavedBufferAttribute | GLBufferAttribute'.

[Sean-Bradley]

Since @types/three@0.149 and @types/three@0.150

Sample code,

const numbers = somemesh.geometry.attributes.position.array

now causes error

TS2339: Property 'array' does not exist on type 'BufferAttribute | InterleavedBufferAttribute | GLBufferAttribute'.
  Property 'array' does not exist on type 'GLBufferAttribute'.

Two temporary fixes,
npm install @types/three@0.148
or
const numbers = (somemesh.geometry.attributes.position as any).array

In plain JavaScript (three@0.150.1), you can still reference a geometries attributes.position.array without issue.

At the time of writing this issue, @types/three@0.150.1 did not yet exist.

[Methuselah96]

An attribute can be a GLBufferAttribute which does not have an array property (see #314). For now you can either cast it if you know it's not a GLBufferAttribute or "use the boolean flags (isBufferAttribute, isInterleavedBufferAttribute, or isGLBufferAttribute) to discriminate between the different options."

[Methuselah96]

Something like #241 could be a potential solution to resolving this friction.

[Sean-Bradley]

Ok, so it works if you do something like this

// using @types/three@150.0
const line = new THREE.Line( geometry, material );
const positions = (line.geometry.attributes.position as THREE.BufferAttribute).array

There was much less friction when the type was auto inferred and you could just write

// using @types/three@148.1
const line = new THREE.Line( geometry, material );
const positions = line.geometry.attributes.position.array

Is it really necessary to now also enforce the GLBufferAttribute type?
along with THREE.BufferAttribute | THREE.InterleavedBufferAttribute
Are you sure?

[Methuselah96]

Yes, that is generally how I've worked around the issue so far.

I agree that the friction is undesirable since the vast majority of three.js code does not use GLBufferAttributes, however on the other end, the types need to be able to support GLBufferAttributes since they're a valid buffer attribute.

I'm looking into ways to reduce the friction as much as possible while still retaining support for GLBufferAttributes.

[Methuselah96]

Is it really necessary to now also enforce the GLBufferAttribute type?
along with THREE.BufferAttribute | THREE.InterleavedBufferAttribute
Are you sure?

Yes, we need to allow the use of GLBufferAttribute, since it's part of three.js. How to allow its use while preserving the ease of using BufferAttribute | InterleavedBufferAttribute takes a little more work, which I am exploring at the moment.

[Methuselah96]

Reopening this to track this issue. I started working on this last month but hit some issues. Digging back into it now.