Count the meshes declared in an IFC-Lite-generated GLB. Zero means the export
carries no render geometry — a structurally valid but empty GLB. The
CLI / MCP exporters use this to fail loud instead of writing an empty file as
"success" (e.g. malformed-but-parseable input, or a filter whose matched
entities have no triangulated representation). Only the GLB JSON metadata chunk
is parsed; the multi-GB binary mesh buffer (the separate BIN chunk) is not, so
the cost is bounded by the metadata size and dwarfed by the meshing it follows.
Count the meshes declared in an IFC-Lite-generated GLB. Zero means the export carries no render geometry — a structurally valid but empty GLB. The CLI / MCP exporters use this to fail loud instead of writing an empty file as "success" (e.g. malformed-but-parseable input, or a filter whose matched entities have no triangulated representation). Only the GLB JSON metadata chunk is parsed; the multi-GB binary mesh buffer (the separate BIN chunk) is not, so the cost is bounded by the metadata size and dwarfed by the meshing it follows.