The 3dsMax cloth modifier is a much understimated tool imho. Defenatly since the 2010 version of max where you have an option to “pressurize” cloth objects. So here are a couple of setups to show some possibilities and techniques for blowing up objects.
To start with the basic technique and how to control the object, here are a couple of pointers:
1. Pressure, the pressure setting controls how much the object will bulge/inflate, this amount works together with the charecteristics of the cloth settings. Like rubber will expand faster and more then the default cloth setting.
2. Mesh preparation, this is one of the crucial things to have the object inflate the way you want. So use proper chamfering of edges, tesselation and use quads as much as you can. Use as much even spacing as you can throughout the entire mesh.
3. Groups. You can assign different cloth properties (with different pressure densities) to a selection of vertexpoints. Create groups for seams you don’t wont to be affected or areas you want to exagerate. This is also very handy to keep specific shapes once inflated. To apply the different properties, go into the subobject mode of the cloth, select vertexpoints and make a group, then with the group selected, click the “use panel properties” to override the overall cloth settings. Here you can change any parameter to affect only the group.
4. Animate pressure. There are 2 ways to animate.
One is straightforward by entering the clothpanel and using 2 different properties on the clothobject (righttop of the panelUI, you can select property 1 / 2) So make property 1 with no pressure, property 2 with pressure. Then in the modifier stack you can animate the slider that blends between property 1 and 2. An example of how to inflate an object from flat to blown up is with property 1 present, you simulate locally so the object falls to the floor, once it’s lying still, start the actual simulation with the property animated from 1 to 2 over time.
Second way to animate is with the override panel properties on specific vertex groups.
Go into the subobject mode of the cloth, make a group of vertexpoints you want to animate, click the override panel properties and start animating the values. This one can give much more interesting effects as you can isolate different parts that inflate seperatly.
5. Tricks. As with all simulations of physical phenomena you need to think inside the box to achieve certain effects. With this I mean first try to imagine how you would do it for a live shoot with real objects, then transfer that technique into your 3d setup. The advantage of being in 3D is that you have more freedom when it comes to guiding objects through invisible helpers or interpreting scale & forces.
6. Damping. Damping does basically the same thing as the native max spacewarp, you can use it to slow down the effect of the pressure.
7. Softbodies. The clothmodifier is perfectly capable to compute softbody dynamics.
Playing around with different clothproperties you can achieve some pretty interesting results.
In case you don’t have Vray, just open it and replace the materials & lights.
You can download the setup here :