Keyframes editing problem

[peterb]

lets say i set three keys: frame 1, 10 ,20.
Then I edit tangents at key on frame 10, so i finally like them

The question is how to edit frame 10 key value and retain its tangents value.

The only way, that works for me is to edit this key in the graph editor. But i would like to do it in more intuitive way, not within graph editor.

Any other method (autokeyframe, set key frame), changes the value of a key, but also sets default spline tangents. Which is not what i would like to get.

Any ideas?

[bumpsetspike]

In my opinion the graph editor is very intuitive to work with but maybe you are looking for something code oriented. The following procedure will change the value of all the keys on the selected object by a specified value. This change will be relative to the current value.
This bit of code will work on multiple objects simultaneously.

//////////////////////////////////////////////////////////////
global proc changeValueOnKey(float $value) {

string $objects[] = `ls -sl`;

	keyframe -e  -r -o over -vc $value  $objects;

}

changeValueOnKey 1;
////////////////////////////////////////////////////////
(this will change the value by 1, adjust this number to different values)

You could put this code on a marking menu or a shelf button and have several value increments at the push of one button. (.5, 1, 10, -.5, -1, -10...) Or, you could put this into a little gui with the value entered into a text field.

alan

www.animfound.com

[nonquad]

I think what Oxio wants is to be able to change the key value by manipulating the object in the viewport, while the tangent remains fixed.

I can relate; I'm not a graph junkie either. Don't get me wrong. The curves are everything. But the curves are only relevant in terms of their relationship to the model and its motion in 3d. Laying curves out on a graph is always going to be taking them out of context, to one degree or another. So IMO, extending the functions of the graph editor into more direct contexts is a valid goal.

That being said... it would be tough. You need a substantial serving of mel -- especially for the autokey functionality. You would have to go hacking the internal maya mel for that; modify the autokey function.
In either case, you will need to use the keyframe, setKeyframe, and keyTangent commands; it would go something like this:

for each channel being keyed
check to see if it has a keyframe at this time
if so, stash its tangent information in a junk variable
set the new keyframe
reapply the stashed tangents

In practice, that would be a fair volume of mel, since simple statements like "for each channel being keyed" imply several other checks in turn.

Anyway. For the record, new keys don't have to set spline tangents. They can also use flat, step, or linear

ex:
keytangent -global -itt linear -ott linear
(itt is in tangent type; ott is out tangent type)

I keep four of those switches on my animation shelf, so that I can decide what type of tangent I want to drop as I'm setting keyframes. Switching between flat and spline keys on the fly is great for rapidly planting footsteps, for example. Unfortunately, there is no option to "keep existing tangents".