The 3d analogue of the triangle then I think you're referring to is called a tetrahedron, one classic algorithm for creating 3d surface representations of volume data is called "marching tetrahedrons" (it's a more correct and was at the time a patent free variation of the marching cubes algorithm).

Something like this? https://arxiv.org/abs/2406.01579

A pyramid is unnecessarily bound, a triangle performs better if it is free flowing. I understand that this performs better because there is less IO but slightly more processing. IO is the biggest cost when it comes to GPUs.