Futureworld (1976) featured a rasterized animation of Ed Catmull's hand. Catmull had a funny anecdote about that model. Not being an art student, he didn't think to cover his hand in Vaseline before casting it in plaster, and pulled all the little hairs out of his arm getting the plaster off.
Futureworld raster graphics
You missed Westworld where they rasterized motion picture film images:
Catmull original animation (1972)
Yep. But fine for a university project, and impossible for a film. I mean...
Transferring the images to film was a task in itself. Because the display hardware never showed the entire image on screen at any one moment, Catmull could see a frame of his work only by taking a long-exposure Polaroid of the screen and looking at the snapshot. Once satisfied, he then shot the footage using a 35mm camera the department rigged to take photographs from a CRT screen.
A friend of mine who used to wrote for Cinefex, etc., tells me:
The thing about vector vs raster may be conflating the issue; I remember several interviews with Larry Cuba (didn’t get to talk with him myself [...]) and the deal was about whether Lucas wanted hidden lines showing or not, and it was an artistic conscious decision to show the hidden lines because he thought it would reflect what an audience expected of such graphics (same thinking probably informs the sound-in-space.)
Anyway, I’m well aware of the state of the art of computer graphics in that era. I am just wondering what the source of this assertion is re Lucas, because the trench animation was rear-projected into the rebel briefing set, which means it was done in 1976.
Regardless of what Lucas was or wasn't shown, I don't think raster was practical in 1976 on a film production's tight schedule, at a reasonable cost, for an extended sequence such as the one in question.
Curious where did you read this?
Here?
A clearer copy of the X Wingd appears here at 1:27:
That demo was made in 1978,
by one of the same guys (Gary Demos) who did the trench animation. EDIT: Whoops! My brain did not have enough coffee when I typed this. It was Larry Cuba I meant, not Gary Demos.
Mea culpa. Demo = X-Wing test. Cuba = Death Star plans.
Here's the X Wing model used:

Which is very impressive for the time, but executed two years after the Death Star plans animation.
CGI history is fascinating. As a point of reference, THIS was state of the art cutting edge real-time rendered CG animation in 1981.