This tutorial shows you some techniques for working with the X-Particles 3 xpVolumeEmit object in Cinema 4D.
One of the new objects with X-Particles 3 is xpVolumeEmit. The concept behind this object is simple, you use the volume of an object to control when particles are emitted. Basic usage is as simple as specifying the emitter and volume(s) to use, the xpVolumeEmit object then keeps track of where the emitter is in your scene and if it enters the volume it will start emitting particles.
You can choose whether the trigger is inside or outside the volume and you can also track an object instead of an emitter. This means you can use the position of an object in your scene to trigger an emitter elsewhere. It is a nice procedural approach to control your particle emission and avoids the use of keyframing parameters, instead, triggering on an event.
If you track an object and use that same object as an emitter, then configure it so the object only emits within specified objects. One example might be dropping a tablet into water and only as the tablet enters the fluid does it start to dissolve and emit bubbles, you could even simulate this in an xpDomain and create a gaseous fluid effect on the resulting bubbles.
The example I show in the tutorial uses a combination of Cinema 4D dynamics to drop the emitting object and as the object bounces it emits particles. By placing a volume above the collision surface and using this volume with the xpVolumeEmit object, particles are only emitted within that collision space. It is a technique which was originally shown to me in a scene by Lothar Mai during the beta testing of XP3, it is such a simple yet effective example of the X-Particles 3 xpVolumeEmit object. Thanks for the inspiration Lothar.
If you don’t have X-Particles then you can grab a copy here.