Hello,
your wrote:
Hi Andy_rst

In Unreal 3 (UDK) there is a feature that uses Nvidia Physics to simulate metaball particles that probably works similarly. And this feature is combined with the Cascade Particle Editor to use the GPU rendering system.
could you tell me more about this feature.i scratched my head how to bring volumetric water into udk,and this could be a good approach to it.also,do you have a idea how to bring vector field features into the editor as well?