Ok i put a custom animations to an object. The problem is the animation is playing in the air and in the wrong location of the object. Plz tell me how i can fix sniff.

I'm afraid there can't be a general answer for this. You give too little details.
Are you animating sim or object?
If sim, are you playing it via AnimateSim or AnimateOverlay?
If object, then did you moved any joints in CRES?

I can't tell if seresv is familiar with them enough to attempt it but yes, they can be done.
With sim animation, see this thread - chelnov said he succeeded and explained what he used.
With object animation, I succeeded myself will post the object as soon as I 'polish' it.

they can be done but their very hard to do and if you want to make complex animations the calculations involved are insane!

BASIC custom animations can be done, yes.

Anything involving more than just simple rotations and translations hasn't been done.

IK object, for example, and I'm 90% sure there are a few settings in there that deal with interpolated frames that we don't understand, and there must be something in there that deals with arm/leg length. (it never changes, even if you make the hand go further)

Aha, so it's sim animation, and looks like you are playing it via AnimateSim.
Try to lower root_trans joint - only you can tell to how much, since you have animation files See, you only bent the legs - if you'd try to do the same in real life, you'd fall to the ground but there's no gravitation in Sims world, you have to animate 'falling' by yourself.

In general, always consider moving root_trans and rotate root_rot joints when you want to change overall position.

thank you XD.

Ok im really have trouble with rotation of the animation. For instance when in missionary position the guy faces the total opposite direction of the girlL . How can i fix this.

Did you tried to rotate root_rot joint on 180 degrees? I suppose you have 2 different animations - for translation standing->missionary, and for looping missionary. In this case it might be enough to rotate root_rot in 1st and last frames of looping animation. You can check and alter the rotation values in ANIM resource in SimPE as well. Select root_rot in the corresponding combobox, and see the values for available timecodes - you should have type=Rotation for all of root_rot timecodes, and value 180 for Z axis in the 2nd editbox following Parameter label to the right.

can u show me a pic plz.

Ok. The picture attached was taken from a randomly picked sim animation - just to clarify where to look for.
So, you select an ANIM resource with animation you want to verify or alter.
In the combobox in the red box "1", you select the joint name. Numbers in brackets after joint name may differ, they correspond to number of timecodes. 'rot' or 'trans' after the ( bracket represent type - rotation or translation - I didn't seen others so far.
Next, you see the tree with timecodes corresponding to the joint you've selected. 'Rotation' here also indicates that they correspond to rotation animation. (I suppose you can apply translation to this joint in an external editor, but not sure if SimPE will 'eat' it.)
Each timecode can have up to 3 parameters - X, Y, Z - they define coordinates (in case of translation) or angles (in case of rotation) of this joint at this point of time. You need to check/alter Z parameter - select it in the tree as I did.
After parameter is selected, look right, to the value in the red editbox "3". This is the actual rotation/translation value - in angles for rotation, in don't-know-what-but-1-is-cell-width for translation. Other editboxes in this row are filled automatically as you alter this cell - looks like just one of these values is actually stored in package, and different interpretations are given just for our convenience.
In the example given on screenshot, joint root_rot is rotated at about 20 degrees. You probably need 180 - check with your animation.

Thank u Jasana for all you've done, because of u i learn how to rotate and lower/raise my animation. Now all i have to do is make my animation more convencing . Tee hee

What kind of calculations? Mathematical calculations or mental calculations. I don't think I would have a problem with the math part it that is what is so hard about it.

it's hard to explain but you need to figure out how the distance between 1 animation frame to the next frame, how long it would take and all sorts of other complicated stuff. at least that's how i think it was explained to me or something like that. anyway it's very difficult and takes a hell of a long time.