welcome to this boiling surface tutorial in this tutorial i will show you how to create a boiling surface using Maya's fluid, with fluids you can create really nice looking effects like fire, explosions, mud, snow, gas, water, clouds, so on and so forth, so this is one of them, keep playing with different settings you will come up with some really cool,
Above we have 3 sets of 2 curves which are on colored layers. The top two yellow curves do not have any continuity at all. The middle two pink curves have positional continuity, meaning that their end points are exactly on top of each other. This will result in a hard edge between surfaces, which is sometimes desired. The bottom two blue curves have both positional and tangential continuity. To verify this one must look at the 'hulls'. Notice that the hulls create a straight line as we transition from one curve to the other. With 3rd degree curves/surfaces, we look one vertex in from the end/edge on each side of the connection point.