According to OGC Indexed 3d Scene Layer (I3S) and Scene Layer Package Format Specification.
10.1 Scene Layer Packages
- On this Archive, an overall compression scheme may be applied. This compression scheme SHALL be either STORE or DEFLATE64. Standard DEFLATE is acceptable as a fallback if DEFLATE64 is not available, but will only work with smaller SLPKs.
http://docs.opengeospatial.org/cs/17-014r5/17-014r5.html
I compressed my file to a .zip and rename extension to .slpk,
If I pick compression method by DEFLATE/DEFLATE64 from 7-zip, add slpk to ArcGIS Earth return
"IO error: Unable to open or read file, it may be in a different format or corrupted: C:\Users\User\Desktop\drome2map_test4.slpk"
But it works if I pick "STORE".
Could ArcGIS Earth support to load compressed SLPK?