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Instructor Note

To clarify why the Boolean union corresponds to the minimum: If d is the distance function for the union of A and B, we want d(x) < 0 when x is in A or x is in B, d(x) = 0 when x is on the boundary of (A union B), and d(x) > 0 when x is neither in A nor B. If d1 and d2 are the distance functions of A and B, then if d1(x) < 0 or d2(x) < 0 we should say that d(x) < 0. The best way to detect if at least one of two quantities is zero is to take the minimum! The other cases can be checked similarly.

coolbreeze

What's the difference between algebraic surface and distance function? I think they are similar

jesshuifeng

I am still a little confused how this minimum function will perform a boolean union of d1x and d2x?

haotingl

Looks like a very convenient function to use for rendering water

fullkeyboardalchemist

I didn't quite understand the answer. Why taking the minimum = a Boolean union of them?

idkLinearAlgebra

Didn't quite understand+1.

yumz

although d1, d2 are distance functions, f(x) = min(d1, d2) is not.