Jump to content
Hash, Inc. Forums
Sign in to follow this  
nyahkitty

Animating a Stem =^.^=

Recommended Posts

Hello,

 

I'm animating a carnivorous plant which consists of:

 

-a stem with several geometry bones

-a leaf branching off the stem to the left and one to the right

-a "head" with a mouth

 

I'm using the TSM 2.0 neck and head rig.

 

It occurs to me that animating this thing would be more natural if I had a null for the end of the stem control chain to drag the think around IK and then also a null for the middle of the stem so that I can control angle and degree of curvature of the stem using one null instead of setting keys for four control bones in the stem.

 

I've attempted to use a combination of Aim AT and IK constraints.

I'd like to know if there is a better way of doing things as I'm not getting the results I'm looking for.

Share this post


Link to post
Share on other sites

I don't know if this is the solution that you are looking for, but it is certainly a way to reduce the number of bones that you use to simulate the stem.

 

Assuming a vertical orientation with the 4 bones numbered 1 to 4 from the bottom up (I also assume that Bone 1 is the parent and that each bone is one lower in the hierarchy). Add two new bones, Control Bone 1 from start of bone 1 to end of bone 2 and Control Bone 2 from start of bone 3 to end of bone 4. Have Control Bone 2 be a child of Control Bone 1 In a pose, select bone 2 make an orient like constraint to Control Bone 1, enforcement = 60%. For bone 1 make an orienbt like constraint to Control Bone 1 with an enforcement of 30%. Do the same with Bones 3 and 4 constrained to Control Bone 2. Now you can bend the stem with two control bones. The control bones have no geometry associated with them.

 

This should also work with 6 bones being controlled by 2 bones, just have the enforcements decrease as you rise up through the heirarchy.

 

I've done this on 3 bones being controlled by one to enable one bone to control the curve of 3.

 

Try playing with different enforcements to give different degrees of perceived flexibility to the stem.

 

Hope this is helpful!

 

Scott

Share this post


Link to post
Share on other sites

I fixed it.

 

Each stem control bone is now constrained Aim At to both nulls.

The enforcement percentages are adjusted as listed:

 

Top = 10/100

Top Middle = 50/50

Bottom Middle = 75/25

Bottom = 100/10

 

Now the rig is easy to control because it's just two nulls instead of 4 bones and I still have independant control of the head. It flexes quite nicely.

 

Yay.

 

P.S. I did consider using the Aim Like Two constraint, but the enforcement only works on both targets at the same time, instead of allowing each target to have it's own independant enforcement value.

 

P.P.S. Thank you for your suggestion, Fishman.

Share this post


Link to post
Share on other sites

No problem.

 

If you want to compare the solutions, here is a simple project file. Sounds like yours is pretty sound though!

 

Scott

Stem_Control.prj

Share this post


Link to post
Share on other sites

Yes, but now I'm now running into a challenge of a different color:

 

I've set keys within the dual null pose for the constraints. The graph editor shows the enforcements going from zero to 100%. The actual visual activity in the CHOR appears as though all dual null pose keys are stepped instead of linear.

 

1% - 100% on the pose slider (constant hold in one position as constrained)

0% = immediately switches to constant position as un-constrained

No gradual transition. I would like gradual transition.

 

Anyone figure out how to beat this?

 

I'm running version 11.1f of the 2004 subscription.

Share this post


Link to post
Share on other sites

If you click the + sign next to the constraint you will see the enforcement, change the interpolation method to linear.

Share this post


Link to post
Share on other sites

Not sure I completely follow the problem. I could use a picture. When you set up the constraints did you use an on/off constraint or a percentage? Are the pose sliders set up to vary the enforcement value or are they actually just varying whether or not the constraint is active?

 

I would try setting the constraints up as an on/off pose. Then set up a separate pose that varies the enforcement value for each constraint. If you really want to get fancy you could use can expresion that would vary the enforcement to one target and calculate the enforcement to the other target. (i.e. Enforcement one = 75, enforcement 2 =100 - enforcement 1 = 25)

 

Love to see your model.

 

Scott

Share this post


Link to post
Share on other sites

The Dual Null Stem Control pose is a percentage of 0% - 100%

The pose is keyframed so that 0% on the slider = 0% enforcement

and 100% on the slider = 100%

 

At least, that's what I was trying to do. Doesn't seem to be cooperating consistently in making the keyframes stick. The enforcement goes back to straight 100% for most of the constraints no matter the slider position.

 

Also, I've tried to alter interpolation in the icon on the title bar of each constraint as found in the PWS.... as well as selecting the keyframes for the constraints in the pose and setting those to an interpolation other than step.

 

Nothing really seems to be behaving as per my direction.

I do wonder if there are a very specific and inegmatic series of steps to setting constraints in a pose so they behave when the pose is used in the. That's been known to happen before.

 

 

MDL enclosed below.

Chomper_JOHN.mdl

Share this post


Link to post
Share on other sites

Is your goal to change how strongly or weakly each of the Aim Ats are enforced?

 

If so then I think that you need to make poses for each Aim At constraint. You're on the right track with changing the interpolation method. Once each enforcement is individually controllable then you can slide them to tweak. This would make the enforcements animatable.

 

No offense, but the TSM rig sems like overkill for this chracter. I think simple bones for each chunk of geometry would work just fine. (Just my opinion - can be tossed in the dust bin with no offense to me)

 

Scott

Share this post


Link to post
Share on other sites

OK, I've gone overboard, but I wanted to try this. Again, discard if you find this useless.

 

I've rerigged your character with no TSM, slide posers on each of the aiming constraints as well as the Jaw O/C and I've made the leaves FK (no poses). I haven't renamed many of the bones and I haven't cleaned up by hiding bones. I also reduced the rumber of splines in the stem for simplicity sake. You can certainly add the splines back in and even add more bones if you want. I think I've restored most of the functionality of the TSM rig with many less bones and a straight forward animateable set of constraints. See if this works or at least gives you some ideas.

 

I think that the FK leaves will be easy enough to work on their own, but you may consider adding a curl pose for each of them. Should be simple enough. I tried posing them curled and it seemed to work well.

 

Again, if you pitch this it won't bother me at all. It was a great training exercise for me in constraints and pose sliders and trying to rig a non biped.

 

Scott

Chomper_JOHN_FISHMAN.mdl

Share this post


Link to post
Share on other sites

Thank you for your help. I will review the MDL file tomorrow. My goal is simply to use a pose to smoothly transition from plant being constrained to two control nulls at 100% enforcement all the way over to those constraints being set at zero. I'm currently liking how the control rig of two nulls is set up..... I'm simply having a challenge getting A:M to turn it on or off in a linear fashion, rather than a step fashion. Did you manage to solve that?

Share this post


Link to post
Share on other sites

I think I managed to solve it. Unfortunately, it is not a one button solution. you have to slide each of the aim ait constraint enforcements from their enforcement to 0. It is set up as a linear interpolation. If you want to make it ease in and out, then you can change to a spline interpolation for each pose slider.

 

Hope it was helpful.

Scott

Share this post


Link to post
Share on other sites

Fishman, nice job. Now for the one slider solution. Create a new pose, at 0% move all sliders to 0% and at 100% set the percentage of enforcement you want for each bone. Now you have one pose slider to control the enforcements and you can still fine tune it with the other sliders.

 

Here's FISHMAN's version of your model with the one slider pose added and added an orient like contraint to the head to orient like the end stem null.

Share this post


Link to post
Share on other sites

Cool. Thanks everybody for all the help here.

Mr. Pickering has been trying to explain the nature of pose sliders to me. Hopefully soon I can post what I learned.

Share this post


Link to post
Share on other sites
Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...