BufferGeometry: Add ability to read interleaved data in computeVertexNormals().

[Mugen87]

From #18433. This modification helps to read interleaved data for normal computations. A new attribute is not interleaved however the method computes now data which are at least usable.

[WestLangley]

Should the title be BufferGeometry: support interleaved positions in computeVertexNormals()?

In other words, is that an accurate description of what this is doing?

[Mugen87]

First, I've hesitated a bit since I wanted to avoid confusion. The PR adds no real interleaved buffer support. Just the ability to read interleaved data by using the generic getter and setters from the BufferAttribute API. But your title is indeed more descriptive. Changing...

[Mugen87]

I've slightly changed the title compared to yours since reading index data is now different, too.

[WestLangley]

The PR adds no real interleaved buffer support. Just the ability to read interleaved data

It seems to me you are supporting reading and setting (existing) interleaved data.

Should the title be BufferGeometry: support interleaved data in computeVertexNormals()?

[Mugen87]

The problem is when the buffer attribute for normals needs to be created, data are not interleaved.

normalAttribute = new BufferAttribute( new Float32Array( positionAttribute.count * 3 ), 3 );

It would only work for existing normals hence it's not a real support :(.

[mrdoob]

Hmm, if this is not fixing it... wouldn't it be better to check if it's interleaved and log a warning that is not supported?

[WestLangley]

@mrdoob He is fixing it. It is just that if the normal attribute does not exist, then non-interleaved normals are added. That is reasonable.

[mrdoob]

Ah, I see! 👍

[mrdoob]

Thanks!