So I’m experimenting with driven shape keys right now. I’m attempting to use it to correct the knee of a frog character I’m working on, whose knee gets funky when his leg extends. I’m at the point of adding the curve to my key that I have created and placed. But I notice that the rotation of the bone I’m wanting to drive it has no rotation information. It stays at 0 degrees…
I assume this is because it’s part of an IK chain, and blender doesn’t store this information for the individual bones in the chain… but maybe I’m wrong.
Regardless, what can I do to make this bone (or any bone that would grab the right rotation information from it) drive my shape key?
First let me preface this by saying that I do not like using driven shape keys … I find them very fussy to use … and that I was hoping that someone else with more experience using them would help/post - especially Toloban (-sic- I think there is an accent over one of the "O"s but I am right now too lazy to find and use the key map …) who is the champion of their use … but he seems to post only occasionally now … so …
I assume this is because it’s part of an IK chain, and blender doesn’t store this information for the individual bones in the chain… but maybe I’m wrong.
And you are right about that but that isn’t why the shapes are not being driven by the bone … more likely it has to with the any one of the variables that you have to key in … like did you set the driven shape to be driven by the rotation of the driver bone ? Or did you set the X value too high for you to see the effect of the driven bone … or too little ? Or is the X value at the right “place”, i.e. maybe it should be a negative value first then zero instead of zero then a positive value … (the MinX and MaxX values I mean)? … Like I said it is a bit too fussy for my taste … but I did manage to get a IK constrained/controlled bone to drive a shape key regardless even if only in one direction (and you are very correct in saying that the rotation values in the Transform Properties window do not show but the data is still there because even those bones can and do drive shape keys ) …
So you might want to post the blend you are having trouble with because it may have to do with any of the various inputs you need to get “right” for the driven shape keys to work … Or you might look over the links (especially Eugine’s video tutorial - that’s what I reviewed to refresh my dusty recollections about driven shape keys - listen especially to what he says about the multiples of ten in the MinX/Y and MaxX/Y values) to double check the settings you have that don’t seem to be working for you …