View Full Version : connecting FK and IK chain scales to main chain

08 August 2008, 12:11 AM
I currently have an FK chain and an IK chain that drive my main spine chain.

I want to pipe in the scale values from the FK chain and the IK chain to the main chain so it blends perfectly along with my IKFK switch I have going on.

I currently am doing this with a scale constraint but it doesnt work. It handles my scaleX(going up the chain) just fine but the scaleY and scaleZ dont have the same values.

To sum up what I want to do is this. I want this to run off my IKFK switch. So if my switch is set to FK mode I want the scale values from my FK chain to go to the main chain, and so on for the IK.

Is there a way to use a series of nodes to do this instead? I cant think of a way to do it.

Anyway help would be much appreciated and thank you in advance. Also I am using Maya.

08 August 2008, 08:35 AM
Ok so I figured it out!

Here is the explanation of my workflow. I hope this helps some other people in a similair situation or any other way as a lot of people have helped me on here. I have attached an image of my hypershade as well. Lets get to it...

What was cool about this is from the start I only had to grab the first joint from each chain and the nodes helped carry the rest.

For each joint I took the scale values and plugged them into a Multiply Divide(MD). I then took my two MD's and piped the values into a condition node. I also piped the value of my IKFK switch into the condition also. Then piped the outputs from the condition to the main joints. It is worth noting my MD nodes are set at "No Operation", this allowed for data pass through.

So for my IKFK switch I plugged the attribute into the First Term of the Condition, btw my condition is set to equal. My second term is set to a value of 1. That way if my first term is 0 it activates my FK and if it is 1 it activates the IK, just like on my switch.

So for my IK joint I took the scaleX and plugged it into Input1X. For the scaleY I plugged it into Input1Y. I didnt need to do anything for scaleZ because I know on my IK and FK chains the Y value is the same as my Z, it is just how I have it set up.

I then plugged the output X from my MD node to the Color If True R, and the output Y to the Color If True G.

For the FK it is run the same way, I plugged the joints values into a seperate MD node the same way as above. The difference is that I ran the outputs of this MD node to the Color If False R and G.

So the last step was to take the Condition outputs and plug them into the main chain joints.

So the Out Color G(which remember is Scale Y and Z) was plugged into the scale Y and Z of the main joints. The Output R was plugged into scale X. I did this for the rest of of the main chain on each joint.

So if moved my IK chest controller up and stretched the chain and scaled out my FK chain and used my IKFK switch it would blend everything exactly.

I hope this helps some of you and if you have any questions please let me know!

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08 August 2008, 08:35 AM
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