Monty Morrison opened the evening with a mihi, before councillor Karen Hunt spoke on behalf of the council.
Ms Hunt said the sculpture represented Rotorua's aim to become a dementia-friendly city.
Spanning 13m x 13m, the interactive installation was built to raise awareness for Alzheimer's disease.
The sculpture depicts the complexity and connectivity of the human brain, representing the rapid-fire transmission of messages between neurons.
Photo/Altitude Photography
Premium sponsor, health and care company Bupa was represented by director of care services and rehabilitation, Jenni Coles.
"A dementia-friendly community starts with understanding what dementia is, and Affinity is helping to do just that," she said.
"It's then about using that knowledge and turning it into action so that people living with dementia are supported to continue doing the things they enjoy."
Children's author, Alzheimer's New Zealand champion and dementia advocate Kate De Goldi rounded out the speeches.
Ms De Goldi had flown from Wellington to share her own experience of losing both her parents to dementia.