In Thailand, a five-day funeral ceremony is now underway and will culminate in the cremation on Oct 26.
Campbell and other volunteers from the local Thai community have been busy folding thousands of paper flowers.
These will be given to mourners and people devoted to the memory of the king to place in front of his image.
Sandalwood flowers have been used Thai cremation for centuries and is believed that its fragrance will bring the souls a sweet afterlife.
"We feel the King is like our own father and many still cry when we think about his death," Campbell said.
The Auckland remembrance is believed to be the first place in the world where Thais will be placing these flowers ahead of the late King's cremation the following day.
Potsawat Wongskeo, 24, a student from Bangkok who is on a month-long holiday in New Zealand, will also attend the Aotea Square ceremony.
"He was the people's king, and that is why people everywhere loves him," Wongskeo said.
Thais around the world have been in mourning since Bhumibol died on October 13 last year after seven decades on the throne.
King Bhumibol reigned over Thailand from 1946 until his death, and had made an official visit to New Zealand in 1962.
In Bangkok, hundreds of thousands of mourners are expected to camp outside the Grand Palace to get a good view of the ceremonies.
Over the last 10 months, artisans have worked to build an elaborate cremation site designed after a vision of heaven.
Songvut Manoonpong, president of the New Zealand Thai Society, said the event would be televised or streamed live at Thai temples to enable people to view the ceremony in Sanam Luang.
There are about 8000 Thais living in New Zealand.
The Thai Government has declared Oct 26 a national holiday, and more than 3000 performers will join the final tribute to end a year of mourning.
On Royal Cremation Day, symbolic royal cremation and prayers will be offered at temples here, Manoonpong said.
There would also be designated sites on the day for people to place paper of sandalwood flowers.