May I ask what is the difference between absolute coordinates in mesh and regular coordinates in babylonjs

Questions
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1

As the question suggests, when performing translation transformations, which attribute is mainly used for operation? If ordinary translation is used, under what circumstances should absolute coordinates be used

2

Absolute, I believe, are in World Space while VerticesData position information is stored in Local Space. The mesh vertices position data is transformed by the GPU into world space through the transformation of all of its ancestors on every frame. I can’t recall whether an individual mesh’s WorldMatrix is representative of all parents, or if it is only the mesh’s matrix itself, still to be transformed by its parents.

A mesh’s absolute vertex position data is the position of each vertex in absolute world space, and is inclusive of all ancestors (parent, parent’s parent, etc.).

2 Likes
3

Can I understand that absolute vertex coordinates are used to render vertices.
In fact, I did not find any attributes or variables for absolute coordinates in the API on the official website

4

Ahh. You’re right. There’s absolutePosition, but not vertex data. See this post for getting absolute vertexdata:

Note there is also a “forceCopy” option in Extract that might help avoid the .clone(), but I’m not sure.

5

Okay, thank you very much.