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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.

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coolbreeze

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

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jesshuifeng

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

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haotingl

Looks like a very convenient function to use for rendering water

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fullkeyboardalchemist

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

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idkLinearAlgebra

Didn't quite understand+1.

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yumz

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