I would like to know if it is possible to edit the mesh of a vertex key from the basis when the vertex key is relative to another key and not the basis. I intend to animate a person sitting. I want the basis to be a person standing, key 1 to be an intermediate position between sitting and standing, and key 2 to be the person in the seated position. When I edit key 2, I want the editing to start with the person in the standing position, and then I want to edit that mesh until it is in the sitting position. However, I want the mesh of the person in the sitting position to morph from the mesh of the person in the intermediate position; I do not want it to morph from the standing position. Is there any way to do this?
Some other things that might help me do this is if there is a way to copy and paste from the edit mode (like there is a way to do this in pose mode of armatures), or if there is a way to change the parent of a relative vertex key after it has been edited.
When you make a new shape key you can make it from either the basis key or another shape key. Just select one from the Shape Key pop-up menu before you press the “Add Shape Key” button. But no matter how you start out making your shape key, it will always be saved relative to the Basis key and the morphing that occurs as you animate will always be the result of the combined influence sliders on any given frame.
Normally you’d make someone sit down using an armature, not shape keys - but I do know Roubal once made some walk cycles using Absolute Vertex Keys in 2.37. I’m not sure if AVKs are really still available in 2.4+.
Generally, animations of people posing should be accomplished using armature animation. Is there some reason you don’t want to use armatures? This is exactly what they are for.
The short answer is that I don’t think there’s a way to do what you’re talking about exactly, although by mixing several shape keys, for example one to go from stand to sit and another to go from zero to some midpoint position (to fix the weird midpoint of the first shape key) and back to zero, you could probably fake an effect kind of like you’re thinking of. It would be tricky, and very limited in its usefulness.
As Andy mentioned, you really should be using an armature for this, doing animation with vertex keys is possible, but why do you want to do it that way? It’s much more work and AFAIK no one animates an entire body that way, shape keys are usually used for facial animation. Are you trying for some kind of squahshy/stretchy 2d effect?
Thanks for the replies. I have been working for a while with armatures and recently discovered relative vertex keys. I’ve had a number of problems with the armature, but while working with RVKs, I have been able to get a final sitting position that looks much nicer than anything I’ve done with armatures. I find it a lot easier and more natural to edit the vertices of a mesh than to move bones of an armature.
I have found that when using armatures, after one bone is transformed, another part of the mesh looks akward. For example, when I had a person sit, the knee looked “pinched”, as in this example: http://img152.imageshack.us/my.php?image=legpinch20070114hv2.png . I was able to solve that problem quickly by making a bone that can move the vertices on the back of the knee. However, there are a number of places vertices need to be moved around like that and I find it obnoxious to create a bone for each small group of vertices that needs to be tweaked.
The problems with the armature are not too difficult for a person sitting. However, I have found armatures extremely problematic when trying to wave a person’s arms around. I think what happens is that edges between vertices get crossed, such as in this example: http://img101.imageshack.us/my.php?image=armcrossed20070114jv2.png .
That’s kinda suicidal. A proper use of vertex keys–actually, one of the actual original uses for vertex keys–is correcting armature deformations like that. You can hook up the shape correction to how far the armature is bent with ipo drivers and stuff.
Man, trying to animate with shape keys… Wow. Good luck though, if you’re dead set on it.
why don’t you use ABSOLUTE vertex keys? Relative vertex keys are useful if you only
animate parts of a mesh and if you want to overlay these animations. But if you animate the whole mesh, you can use absolute keys.
Thanks for the suggestion. I have made an action with the armature to animate a person sitting, and I used relative vertex keys, with drivers attached to the bones of the armature, to correct things like the “pinching” at the joints and to animate the buttocks as the person sits. For the most part, this worked pretty well. The only problem is that I when I edited the mesh to make the RVKs, I could not edit the person in a sitting position. Though I was able to effectively solve the armature deformities with the person in the standing position, it would have been more convenient to edit the person in the sitting position since that is the position on which the armature deformities existed.
In the modifier panel beside the armature modifier there are three buttons ; enable during rendering / intereactive display / editing. Turn on the editng button, and there is another button just to the right of it (ToolTIp is "Apply modifier to editing cage during EditMode. Turn on that button as well, then when you edit the mesh it retains the position of the armature.
I think what 4096 may have meant is that it’s near-impossible to edit the mesh when it’s deformed by the armature. This is because Blender tries to edit in original mesh space rather than with respect to the displaced mesh so a vert that’s been rotated 90deg will need to be dragged in a different direction to what you actually want it to move.
I don’t think there’s any solution to this yet except to switch back and forth between deformed and non-deformed while editing. So, even if 4096 didn’t mean this, it’ll soon become apparent
It’s a bummer but it’s quite a new feature (driven shapes) so hopefully the little irritations will be dealt with soon.
This is because Blender tries to edit in original mesh space rather than with respect to the displaced mesh so a vert that’s been rotated 90deg will need to be dragged in a different direction to what you actually want it to move.
Are you sure this is still the case? It seems to me that editing deformed meshes improved a lot with 2.42. Have you tried this lately?
Are you sure this is still the case? It seems to me that editing deformed meshes improved a lot with 2.42. Have you tried this lately?
Yep, in my 2.42 versions (including Nov 06 sculpt cvs) it is still a problem. May have been fixed in more recent cvs versions. Holding my breath for 2.43.
I’ve been trying too edit using absolute keys in 2.42, but for some reason I select ‘insert key frame’ then ‘mesh’ but it doesnt ask if i want absolute vertex keys. Are absolute vertex keys still available in 2.42??
Gert42: Sure, just go to F9->Shapes tab and turn off Relative. A good workflow for absolute shape keys is: for each key position, set the Mesh key, then tab into edit mode and adjust vertices. Also to go past 100 frames, you will need to make an IPO curve for the first (Basis) key. There’s a recent thread on this somewhere.
maybe the biggest problem is in the mesh not in the animation method.
a text from bay raitt and greg minter (the PDF is about 430 KB). http://www.ogle.com/articles/digital_sculpting.pdf
its old but it is basic and pure sub-d modelling philosophy.
if you are to lazy to read the 13 pages, jump to the ‘modeling for animation’ chapter ( from page 7 on or especially from page 9 second paragraph to page 10).
Actually, I was not aware of the features in the modifier panel that Mike_S mentioned. Turning on the editing button worked very well. When I edited the mesh, it was near impossible to modify any vertices that were part of the vertex group associated with the bone being transformed, but it turned out those were not the vertices I needed to modify. Thanks both of you for your help.
