Susan Gibb writes of Surfaces
In your meaning of extrusion, I would suggest that by its protrusion that it intrudes beyond its original delineated space. Or maybe that’s just the space it’s been assigned.
Extrude typically goes with the idea of thrusting into our out, as in the edge of a cabinet, door, or vehicle rearend. So protrusion would be a good relation. Intrude would be a judgement or interpretation as would “original space,” so I would stay away from “intrude” at this point. Are there finer points to make about spatiality in terms of extrusion. I think yes. Consider the question of “original space.” A garden is very much something that extrudes and changes shape, therefore creating a warping of the experience of environment.
We know that experience is layered. Beyond this computer screen in front of me is a stretch of surfaces in 3 dimensions. The computer screen is also at play here in its flat space (this all eventually runs back to the nature of digital space) where edges become mathematical. The edge of the chair nearby floats, more nearby than the edge of the table.
I knew it sounded rather anal the instant I hit the submit button. You’re right; intrude is a judgement call. After all, who owns space? And once an object is moved, it replaces other space even as it gives up its own. Extrusion, to me, means forced through, i.e., a spaghetti machine. However, I do see your meaning in the garden reference as an excellent example of a space that is in constant motion and change.
And by the way, I take it you’re not considering here the other possible eight dimensions.