IPO control of IPO curve...?

Just wondering: is there a way of using an IPO curve to control the effect of another IPO curve?

Let’s say that I have a cyclic IPO which changes the size of the default cube. animate that, and the cube increases and decreases in size until the animation is stopped. So, let’s say that I want the effect to start gradually - i.e. ‘fade in’… is it possible to combine the cyclic IPO with a ‘ramp’ IPO?



First of all, it sounds like you’re describing the action of the Time IPO.

Otherwise, look at Actions and the NLA Editor. These are all higher-level constructs, built on top of the IPO mechanism, and they provide for such things as “fade-in” and “fade-out.”

I was working with Blender for quite a while, futzing around with IPOs by hand, until a little voice whispered, “Gee, I wonder what these other windows do?” %| It turns out that IPOs are a very primitive, “foundation” mechanism upon which several layers of more sophisticated functionality are built.

You might also do the expanding-cube thing :wink: using “Relative Vertex Keys,” where you describe the “normal size” pose and the “expanded size” pose and are able to morph the cube from one to the other. This is more flexible than simply “scaling” the cube.

As you begin to work with Actions and NLAs, there is one particular gotcha, and that is that an “Action” is initially linked to an object and must be converted to an NLA strip; otherwise, it will remain attached to the object and will continue to influence it, interfering with or superseding the intended actions of the NLA strip.

Fair warning: You will definitely reach a " :o point" with all this stuff, fairly quickly and frequently. It’ll make you :-? then :x then :< and then :smiley: in very quick succession! And then, just as you start to feel 8) , it’ll do it all over again. %| Don’t feel lonely when that happens.

… I guess what I’m probably after is doing this in the context of RVKs - let’s say I have a number of RVK positions, and I have a nice cyclic (complex) behaviour that I want to ‘fade-in’ - From my recent experience with RVKs, I don’t believe you can use action strips with RVKs - they are for armature-based animation only.I’m mainly just thinking aloud here - trying to build up a pallette of techniques to use in future animations; and this is a thing that I can imagine using :slight_smile:



hm, this sounds familiar… check this out, maybe this comes close to what you’re looking for.
i also made a feature reqest on blender.org for incorporating sliders (much like RVK) for armature actions. i.e, once an action is created, it’s animation can be controlled by a slider. multiple actions means multiple sliders which can be mixed, like RVK’s. this shouldn’t be hard, since there is already the actions constraint(as you’ll see in the tutorial), but it’s a pain to set-up and use (one constraint for each and every bone used, no thanks, this is something for sisyphus)

The “D” (delta) size/loc/rot is like a ramp; it tags onto the existing IPO.