let's say you have a landscape/heightfield that has its height defined at every integral coordinate. what is the fastest way (computationally, in "CPU time") to calculate the height at an arbitrary real-numbered location? i.e. how to calculate[3.25, 6.78] given the heights at [3,6], [3,7], [4,6], [4,7]? i can think of a few ways, but they all involve a lot of calculation. i'm wondering if there are any super-efficient cool ways that anyone knows. thanks