I don´t find a way to:
Is it clear what I want? Are these things possible? I’m pretty sure at least point 2 should work, but i don´t know what to ‘key’ then…
Well, I’d really like to learn the answer to #1 , but I can tell you that animating a metaball going through another one is REALLY easy. I’ll show you how.
First, creat 2 metaballs spaced a few grid units apart.
Then, select one, hit "I"key, choose “Loc”.
Next, hit the "right-arrow"key once. Your frame should be at 11
Move the metaball you selected over a few grid units.
Hit "I"key, choose “Loc”.
(hold down control if you want the object to snap to the grid when you move it)
Keep doing this gradually until the selected metaball intersects, then passes through the other metaball. Then, hit Shift + Left arrow (or the down arrow repeatedly) to get to the beginning frame of the animation. Now select the Display buttons (F10)–Oh, wait, first add some lights and a material to your balls (they should enjoy that 
) and move your camera to a good view. Hit zero on the numpad to see things from the camera’s perspective. Make sure that the camera is far enough away to see the whole animation. NOW hit F10, choose ANIMATE button, sit back and let it render the animation, then hit play. You can kinda preview the Animation just by hitting Alt+A. Sorry if this sounds basic, but this is the kind of instruction I required when starting out. If this doesn’t work for you, just lemme know and I can email you the Blend file, along with slightly better instructions. Good luck, and I really hope someone else can answer the other two questions.
1.) similar to vertex keys. [I] insert —> curve
3.) have to think about.
3 cannot be done, unless you recalculate the particles everyframe.
Martin
These were the ‘obvious’ procedures I´ve already tried, but they do not work…
The metaballs shall be in the same metaball system (to get the fluid effect as if two drops become one and then separate again), so if I key the location, the location of the whole system is keyed.
I also thought to key the curve, but the curve does not bend.
I know how to animate normal stuff like meshes, vertices and non-static particle systems, but this is beyond my imagination.
yes and no. If you insert the second ball in edit mode you can’t animate separately. If you insert ball one, [TAB], insert ball two, they still belong to the same system but can be animated separately.
For the curves: Insert the curve keys in edit mode, leave edit mode after every inserted key and enter it again to make the transformations and set the next key.
Thanks Tordat,
it works although I have not quite understood why I have to leave edit mode and go back again…
Am I the only one who wants to get animated static particles? I am thinking about a weird underwater creature with thin waving tentacles (like in ‘the faculty’)
Am I a forum groupie now???
Don’t worry, neither do I and apparently just a few do if any. It seems to be a way of marking that one key has been set up and what comes next should generate another key instead of just keep working on the first one.
Am I the only one who wants to get animated static particles? I am thinking about a weird underwater creature with thin waving tentacles (like in ‘the faculty’)
No. I personnally wish that every parameter would be animatable by default no matter if it seems to be useful or not at first. Sooner or later, somebody creative will find out a way to use them that nobody suspected before. Until now I haven’t had any success to make that concept of freedom and power very popular indeed.
There will be an effect module by GPG (grand daddy Guignot) in the next Python API. It should render you able to do what you need.
Am I a forum groupie now???
You could be a darn monkey in my place if you want : no charge.
Jean
Well, you could always model the tentacles and animate them with armatures.
Martin