You're all wrong. To quote the original poster: "first, non-vector, 3d arcade game". Arcade being the operative word and assuming 3D implies depth. Consider this, Arcades predate the video era games beginning in the mid 70s. Before that, you had Arcades full of Pinballs and EM gun games like those found at many amusements parks and what not. Either of which could qualify as 3-D games since pinballs roll across the 2D plain of the play field. However, I would say that the 3D effect on the EM gun games are much more effective(and novel) than the Pinball effect. So I would argue that some 3D e.m. shooting gallery with a cool black light and mirror to reflect the image up (much like SI and DOT) would be the "first, non-vector, 3d arcade game" where "non-vector" is a bit redundant.
That being said, if we replace arcade game with video game, then all the above comments would probably be true for the most part. But if we use the 3D implies depth, than Space Invaders could be the first. Although, there is probably some other similar game like Sea Wolf that I'm not thinking of that does about the same thing. The only thing I would add is that I' Robot was the first video game to use true Polygons which have become synonymous with 3D gaming. So that may ultimately be the right answer to the question the OP intended.