Minor nitpick - Voodoo 3 and TNT2 weren't competing with Radeon. Among that generation were the 3dfx Voodoo 3, NVidia TNT2, S3 Savage4 and Matrox G400 - ATI's offering around this time was the Rage Fury.
The ATI Radeon was part of the next generation, along with the Geforce 256 and S3 Savage 2000.
edit: or possibly even the one after that? Wikipedia tells me the Rage Fury MAXX was out around the same time as Geforce 256, and Radeon only showed up around the time of the GeForce 2 family. The MAXX slipped from my memory, it was pretty iirc finicky card (performing badly and having buggy drivers, possibly hardware?) and a bit of a disappointment.