Since the question was asked in the LODs topic too, I thought I’d provide a bit more explanation:
- The glTF format is used so that the buffers provided in binary format can be sent directly to the GPU.
- For the GPU, a vertex is not only a position in space but also includes attributes (normals, uv-coordinates)…
- Hence depending on your object, a single vertex in space may be shared by multiple faces for which some of these attributes are different (think a cube with hard edges where each corner exists 3 times with 3 different normals).
In case this is useful, the topic has also been discussed here.
Best regards,
Eric / Asobo