How do I keyframe not so obvious parameters?

I know how to keyframe the obvious Translate, Rotate, and Scale but how do I key the strength of a magnetic field?


There are several basic ways to accomplish this, depending on the context:

  1. In many cases you can point at the panel in question (eg the Fields panel) and press the I-key to bring up a menu of keyable parameters.

  2. More robust: you can also build IPO curves for all animatable parameters - select its name in the IPO list (eg, FStrength), then Ctrl-LMB in the IPO window to add points.

  3. Constraints have influence sliders that can be keyframed with the Key button

  4. Shape keys have a value slider that automatically sets a key when you change it.

Thank you…Superb! :wink:

Notice how the IPO-window has a drop-down list: there are several groups of IPOs available … and just about anything-and-everything in the Blender system is ultimately influenced by this means.

(“If you can understand IPOs, and Nodes, (and oh yeah, modifiers and constraints…) and the various things that are built on top of those notions, you’re well on your way to mastering … well, feeling a little less stupid in the glorious presence of :wink: … Blender.”)

It’s not always obvious how it works, though: the “IKEY” does not always work as you think it should. But it’s still Bezier curve editing. You choose an IPO and add a point to it. Each point that you add, for that curve at least, is “what a ‘keyframe’ really is.” So think in terms of “I’m editing curves.” Pretty much all the stuff that is discussed in the modeling sections about dealing with curves applies the same way here.


Some parameters can not be animated. Most notably are the parameters of modifiers.

One of the things the new event system and data api in 2.50 will allow is the ability to animate anything and everything. As of now though, Blender has a of animatable properties.

Another question for all of you Blender experts out there(hehe); I’m using the Explode Modifier to explode a cube. I’d like to stop the simulation, have my camera rotate around one of the pieces, and then continue the simulation of the exploding cube.

How would I do this? Which parameter would I key?



I can’t get the particles to come to a complete stop, but I did manage to get them to slow down.

Select the object you want to explode and then the particle system it should be before the explode modifier in the stack. Then open an IPO window and change the default Object display to Particles. Then Click on the E_Speed parameter and CTRL-Click in the IPO window to lay down some control point (you need at least two). If you set these control point near ZERO on the graph, this dramatically affects the speed of the particles. You can even make them go backwards by putting in negative numbers.


explode_modifier.blend (233 KB)

I’ll mess around with this, thanks.

You can also accomplish this with a Time IPO on the emitter object. When a Time IPO has a positive slope (going up to the right) the animation goes forward in time. Add a horizontal segment to the Time IPO to “freeze” the action; this is when your camera revolves around the scene.