3MFLoader: fixed multiple build items refecering the same object bug

[soaresrl]

Multiple build items that reference the same resource object were being ignored as they referenced the same Object3d object. Also the build items meshes were using the same BufferGeometry's reference.

[Mugen87]

Also the build items meshes were using the same BufferGeometry's reference.

This is actually intended. Why do you think should it be different?

[soaresrl]

Also the build items meshes were using the same BufferGeometry's reference.

This is actually intended. Why do you think should it be different?

Actually I thought it was not inteded. I had problems applying matrix transformations and as the build items reference the same buffer geometry both had the geometry updated. The first part was also intended? Because I came across some 3mf files with several build items referencing only one resource object, so I thought could be a problem.

[Mugen87]

Because I came across some 3mf files with several build items referencing only one resource object, so I thought could be a problem.

Do you mind sharing such a 3MF file for testing?

When I remember correctly cloning should only be necessary in context of <components> elements.

[soaresrl]

Do you mind sharing such a 3MF file for testing?

@Mugen87 Sorry for the delay, here is a file with one <object id="1"> and two items <build><item objectid="1" /><item objectid="1" /></build> that references the same <object>: https://we.tl/t-qaJIn4l4ZF

[Mugen87]

Okay, this change is correct. I've checked the specification and indeed multiple items can refer to the same object resource by having the same value for objectid.

[mrdoob]

Thanks!