SmartSkin

While you can still just rightclick a bone and choose>new>smartskin and open a relationship window, I have started just using an action to test my models movements, adding smartskin keyframes where necessary. It is easy: When you are posing your model and reach a position that needs some smartskin, just right click the bone driving the problem area>new>smartskin you will immediately enter muscle mode and you will see that the relationship toggle is active. adjust the cps that you need to, and then un-toggle the relationship icon. You are now still in your action and can continue posing your model around. The smartskin adjustments are stored under bone relationships, and A:M will interpolate between them as you pose your model in the future, they will stay with your model. If you clear the test action that you were using to make them, you will find that the smartskin adjustments will stay with the bone, next time you pose the model! It's great, you can add smartskin adjustments in this way at any time in any action or choreography and all of the little tweaks that you make become part of the model (You can delete them also--they are in the relationships folder). Hope this is helpful.

Remember that interpolation between key frames is based on translation rather than rotation. If you are trying to smooth transition on a twist motion, you'll get the effect of 'shrinking then growing'. You could try adding extra key frames in this case, or use intermediate bones with a roll like constraint.

You just need to add more key frames to your smartskin for the forearm rotation. Let's say you have a fine looking forearm at frames/degrees 0 and 180 in your smartskin window. But frame 90 is a shrunk mess. You are going to have to add a new keyframe at 90 and fix the points so that they look good. After you do this I bet the action through the rotation of the forearm will work fine. If not, find the most extreme problems frames and fix them. You are right in saying that SmartSkin, like Muscle motion, defaults to linear interpolation.

I've used only SmartSkin on quite a few forearms and it works great.

Glen Crowell

The manual is correct assuming your two models share the same mesh as in down to the cp numbers, bones have names cps have numbers. Copy and paste keyframes, resuseable actions and everything else hinges on AM knowing where to put the numbers.

If you have an action with a bone called right upper arm and try to apply it to a model with the same exact bone named right bicep, well AM doesn't know where to put that channel so it doesn't get applied to anything. With smartskin it's the same thing except a shoulder cp's name is CP#13308, you could have a completely identical cp in another model named CP#18565, but you may have CP#13308 in this model in the foot say, well when you paste that smartskin key over it will offset that cp in the foot not the shoulder, the program only understands the names and if you don't have a cp with a matching name they won't get applied at all.

However if you used the exact same mesh as your first model, without editting any of the areas that will be smartskinned you can paste the smartskin container from the initial model into the new one with a pair of text editor windows (I've done it and it works provided the cp's are named identically), or copy and paste the smartskin keys as per the manual.

That should eliminate the confusion as to what works/doesn't work and why though I doubt it'll bring a smile to your face in your present situation. Getting smartskins to copy and paste over a variety of models successfully is about as spontaneous as a contract killing, though it is possible if you lay groundwork and stick to the plan.

Matt Andersen

A:M doesn't support bias adjustments in smartskin as yet.

Glen Crowell

Nope. Not with channels. This is also a feature limitation with pose sliders as well.

You have to make any changes to a negative value in the smart skin window itself.

Glen Crowell

Very picky. Smartskin mirrored is based on exact coordinates. that means a CP on the right finger says 52,7,5 the left finger should read : -52,7,5

exact coordinates. mirrored on X axis. the easiest way to do this is to set your pivot to 0 on the X-axis before you flip and attach. I bet it will work if you do that first.

-Joe Cosman

This is the only problem with smart skin as far as I am concerned, the motion is additive so it becomes one of those, 'we need to be aware of what my x-axis is going to do when the y-axis is moving.' situations. This just requires a lot of planning and fore thought. and is why IMHO smart skin works best when applied to only one axis of movement. but as to your question: I do this: I open up three or four windows one for each smartskin and an action for the object I am applying the smartskin to. In the action window I set each axis that I plan on moving to the extreme position of it's smartskin (so if I want the smartskin to go 90 deg in x and 90 deg in Y smartskin I might put the bone in those positions in the action window, I then set a key frame move forward and change the position to halfway between extremes then another with the bone at it's origin. needless to say with all those windows open I run in wireframe mode. then I set the action window back to the first frame (the extreme position.) then I move each smartskiin window to that same position (if you use Eular interpolation in the action window this whole process is easier.) I position each smart skin one at a time, moving only the points that I feel absolutly must be moved. (note also that I just learned that you can apply constraints to a smartskin window by dragging and dropping the pose with the constraints into the smart skin window I have not yet tried this but the new manual says it can be done so... anyway....) as I work I constantly refresh the action window and see what my additive changes are doing to the model in it's extreme position. I tweak until I am happy with the way it looks in action regardless of how it might look in the smart skin window. then I move everything to the halfway point and tweak again...if I need more inbetweens in smartskin I will first ad the position to the action window and then go back to the smart skin.

so this takes care of the additive movement. but if this doesn't do it for say straight x axis movement then I might add another bone as a child of the main bone just to handle x axis rotation (maybe using a constraint setup instead of childing it actually so that you can change the enforcement value of the x axis bone to tweak the mesh as needed, with a pose slider...), but anyway I go through and do the same thing with this bone, but just in one axis, adjust it in the smart skin window and watch the results in the action window. I do the same for each axis

it may not be a perfect solution but it's the best I have come up with so far... if any one has a better/easier solution PLEASE let me know, I'd love to spend a lot less time on this than I currently am :)

-David Rogers

do this:

1. select bone and smart skin axis desired
2. select its twin on the opposite side-do the same as step one-now you have 2 windows open
3. make smart skin key frame-----select the altered cps------copy
4. go to twin bone-----make sure bone is set to correct frame (to see the proper mirrored rotation, one bone will be a positive number and the other will be a negative number)
5. select the same cps to be altered- go to edit and paste mirrored

that should do it

check it in action. saving and reloading may be necessary to see the results in action.

who's yer buddy : )

S.A.Y.

Make sure to select the CPs around the left shoulder before copying and select a similar group on the right shoulder before choosing Paste Mirrored. Make sure that the "Keyframe Muscle Motion" button in on. And make sure that you were actually choosing Paste Mirrored (in the Edit menu) rather then regular paste.

--Raf Anzovin

It is definitely possible, using the new Paste Mirrored feature which will switch the CP number your pasting in so that it will work on the other side. While Smart Skin is dependent on bone movement, it does not have to be tied to any specific bone any more then Pose Slider muscle motion needs to be tied to any specific slider--as long as it's happening in the Left Arm window it will not be dependent on the Right Arm and vice versa, whichever one the original movement was created in. You do NOT have to go and add Smart Skin to all the joints the long way.

--Raf Anzovin

OK, FWIW I -have- successfully used Copy->Paste Mirrored on Smartskin with no difficulties. Very helpful. So it is designed to work that way.

Here's my procedure:

(1) Create a model which is -exactly- mirrored around the X axis. Do this by removing everything on the left side, copying, mirroring and attaching the right side.

(2) Set up the smartskin for the right bone. In my case, it had keyframes at -60, -40, -20, 20, 40, 60. Leave the window open.

(3) Hide everything except the points I'm going to be working with, both left and right sides.

(4) Make absolutely sure that your frame-bar settings include at least "Muscle Keys" and "Full Model".

(5) Create smartskin on the left bone. Go back to the Right-skin window, go to frame 60, *select* all of the points of the right eyelid. Copy.

(6) Go to the left-skin window. Go to frame 60. Deselect (using the Return key). Paste-mirrored. Grin.

(7) Repeat for other frames.

Anyway, that worked for me. Your mileage may vary.

-- Tony

Well, for all those folks who have not yet played with the Beta, here's the brief description.

Pose Sliders (which appear, if I recall correctly, in V6) allow you to create little mini "pseudo-actions" with frame ranges from -100 to 100. Frame0 is always the base-point of the model (with no action applied). Then you can define keyframes anywhere in the -100 to 100 range. Later, you can apply the "Pose" at anything from -100 to 100, and the interpolated frame for that value will be applied to the model.

With me so far?

The benefit of Pose Sliders is that they are -additive-, unlike old V5 actions where only the last action you apply gets remembered. So if you have Pose 1 which raises the cheeks for a smile, and Pose 2 which stretches the cheeks outward (for whatever reason). If you apply both Pose 1 and pose 2, the cheeks get raised and stretched, by adding the linear transations of the CPs involved. Very useful.

So, what does this have to do with SmartSkin? Well, SmartSkin is basically a direct connection between the rotation of a given bone and something remarkably like a muscle Pose Slider. Basically, you get to define a mini "pseudo-action", just like a Pose Slider, except it ranges from -180 to 180. This is associated with one of the axes of bone rotation (the X, Y or Z axis, which corresponds to (I think) Latitude, Longitude and Roll respectively). Then, as the bone is moved in animation, the appropriate frame of the pseudo-action is automatically applied.

The wonder of this is that the SmartSkin can change muscle points that are -not- assigned to that bone. So you can have multiple bones, all automatically influencing the same CPs. This is a real life-saver in previously complicated setups like buttocks and shoulders.

And that's SmartSkin. Make sense?

-- Tony