Creating Buoyancy without Reactor
Now that I've shown you Flex can be used to simulate water ripples, you may be wondering about the other part of reactor water simulation in 3ds Max 2012: buoyancy. Buoyancy, which causes objects to float on water, is a little trickier now that we don't have Reactor. To accomplish this, we'll have to use a script controller for position and rotation. Fortunately for us, Shawn Lewis over at Script Spot, released a handy little MaxScript called Follow Surface which allows us to make objects float on the water with very little work. I've tested this script in 3ds Max 2012 and it works flawlessly.
Simulate Water with Flex in 3ds Max 2012
Water Ripples using Flex
With Reactor removed from 3ds Max 2012, users will now need to explore other means of animating physical simulations. This tutorial will cover replacing Reactor's water simulation using Flex, a tool already available in 3ds Max. While you could simulate general water movement or ripples using the Ripple modifier or the Waves Standard Map applied to a Displacement modifier, these options require manual animation and can't be affected by dynamic collisions. Flex, which you may have used to add jiggle to fat characters, simulates soft-body dynamics using springs. It's a very powerful modifier which can be affected by forces and deflectors to simulate cloth, rope, water, and other soft-body dynamics.
3ds Max 2012: Farewell Reactor
Having recently upgraded from 3ds Max 2011 to 3ds Max 2012, I've been busy learning how to use some of the shiny new features. Because of my soft spot for physics engines, I was excited to hear about MassFX for 3ds Max. Sadly, Autodesk also removed Reactor, a physics engine that had been in 3ds Max for years. Unlike Reactor, MassFX does not simulate soft-body dynamics, cloth, water, ragdolls, etc. It only simulates rigid bodies!