I'm a beginner in 3D studio, but I want to animate an object disappearing and reappearing instantenousely. Like say from frame 0-29 the object is there and sitting still. But on frame 30 it instantly is gone. I can't use scale or change radius to 0 as it will show an animation of the object shrinking until it dissappears but not dissappearing instantly. Thanks in advance. :)

If the object is scaled to 100% at frame 29, and 0% at frame 30, how can there be any animation? There are no frames available to interpolate the action of shrinking. It will instantly disappear.

The reason it's not working for you is because the keyframes for scaling, rotation, position, etc. are all seperate. If you only change the scale at frame 30, then it interpolates between frame 1 (the default starting keyframe) and 30 (the one you set).

Just put in a keyframe that says it should be full scale at frame 29. And if it acts funny (ie. scaling larger before frame 29) make sure it's set to interpolate in a linear fashion (directly keyframe-to-keyframe, with no fancy calculations for smooth movement). You can look that up because I forget how to do it.

There should be a way to change the visibility between 0 (not visible) and 1 (visible), and animate that parameter.

here is how i do it.

select your object > goto graph editors > dope sheet
in the dope sheet window select your object left click its name
goto tracks (menu bar) > visibility track > add

open up your object by clicking the + next to its name
select Visibility add 2 key frames ( select the "add keys" icon from the graphic menu below main menu ) then click on the time line. The first key is when you want it to start to fade the second is when it stops.

select the last key ( right click ) turn the value down.. ( 1 = full visibility )

Thanks for the help. Itworked. :)