Because SketchUp is single-threaded for viewport, heavy 1828 materials can lag.
Newer V-Ray versions prefer .vrmat files. If your 1828 pack contains .vismat files:
Because SketchUp is single-threaded for viewport, heavy 1828 materials can lag.
Newer V-Ray versions prefer .vrmat files. If your 1828 pack contains .vismat files: 1828-mat-vray for sketchup