Doc:Manual/Animation/Basic/Tools/Creating an Ipo

From BlenderWiki

The simplest method for creating an object IPO is with the "Insert key" (I) command in the 3DWindow, with an Object selected. A Pop-up menu provides a wide selection of options (Insert Key Menu.). Selecting an option (eg. Loc) saves the current X/Y/Z location and everything takes place automatically:

• If there is no IPO block, a new one is created and linked to the object.
• If there are no IPOCurves in the channels LocX, LocY and LocZ, these are created.
• Vertices are then added in the IPOCurves with the exact values of the object location.

[edit] Example

Position your Scene to Frame 1. Add a mesh object to your Blender Scene. The object is added at the 3D Cursor loctation in edit mode. Press ⇆ Tab to leave edit mode, and I to Insert a key. In the popup Insert Key window, select Loc. In your Ipo Window, you now see, for the Object mode, the LocX, LocY, and LocZ channels have been filled and selected. There is now a (flat) curve with curve points at Frame 1. The Y value of these points define the location (value) of that channel at that point in time.

Go 30 frames further on (3 x ↑) and move the object by Grabbing it and dropping it somewhere else. Again use I. Now we can immediately press ↵ Enter since Blender remembers our last choice (Loc) and will highlight it. The new position is inserted in the IPO Curves at frame 30.

We can see the animation by slowly paging back through the frames (←). The object moves between the two positions. In this way, you can create the animation by paging through the frames, position by position. Note that the location of the object is directly linked to the curves. When you change frames, the IPOs are always re-evaluated and re-applied. You can freely move the object within the same frame, but as soon as you change frame, the object 'jumps' to the position determined by the IPO.

The rotation and size of the object are completely free in this example. They can be changed or animated with the Insert key procedure by selecting from the I menu the other options such as Rotation, Size and any combination of these.

[edit] Recording IPOs

Blender has a built-in physics simulation engine ("Bullet") which allows you to define objects as having a mass, and being solid, and having velocity and angular momentum. Once you set this up, you can use the main menu Game->Record Game Physics to IPOs" selection to toggle on recording. Now, when you next press P for Play, the actual location and rotation of the selected object will be recorded for each frame of the animation.

Use this feature for recording complex interactions of multiple animated objects. For more information on using the Blender Game Engine, check out the appropriate wiki book from the main wiki page.

[edit] Linking IPOs

An Ipo is (in Blender) a datablock, in that it is a separate object. You make it act on an object by linking it to the object. You can offset that link using the TimeOffset in the Anim settings for the object.