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The bracketed number encodes information about how the object was exported. The first number indicates how faces were separated, where:
| Number | Separation By |
|---|---|
| 0 | None |
| 1 | Face |
| 2 | Material |
<Component#1>, then, was exported with its Separate by Face flag enabled. The second number indicates if UV coordinates were overridden, where:
| Number | UV Coordinates |
|---|---|
| 0 | Default SketchUp |
| 1 | Ignore Distortion |
| 2 | Cubic |
| 3 | Planar |
| 4 | Spherical |
| 5 | Camera |
<Component#1> was exported, then, using Cubic UV coordinates. The third number deals with situations in which multiple copies of the same entity are exported, and indicates with which copy any given object corresponds; this, then, was the second copy of <Component#1> to be exported (numbering starts at 0).
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