I am trying to inflate an animated character using vellum and a custom leading edge for inflation.

I have 2 meshes that are both animated, the first is the normal character (let's call it charA) the other is the inflated character (let's call this charB). I am running a pyrosource spread SOP over a static charA and copying the temperature attribute generated onto the animated charA. This gives a nice natural leading edge for the inflation.

I am then using the animated attribute to lerp between charA and charB and making this my target for vellum. Inside the vellum solver I am using a restblend with the blend set to a constant of 1. This works well, the character loosely follows the animation and inflates. Which makes sense as it is calculating the restlength per frame which are growing and shrinking as the character is animated.

However, the issue is that I want to be able to control how close the cloth follows to the animation, pinning in certain areas so I can art direct my shot more. When I use a pin to target constraint it is ignored whilst also using the restblend inside the vellum solver, is it possible to use these together? Or is there a better method to control this?

Attached hip file of my current setup using the rubbertoy as my character. Thanks in advance for any help or advice.

I think it's because your soft pin cons are trying to match the restblend which does not follow the animation, a easy way is just to add the animation into your target geo.
See the attach file, I just change the target to match the original animation.

I know this is late, but I found out what causes this. I had the exact same issue. It's because the vellum rest blend is changing data on the constraints made by the pin constraints. The solution that kevin posted is probably the way you want to go. But I am attaching this example that fixes the issue/proves that the rest blend is messing up the pin constraints.

If you look at my attached hip and the photo, I limited the constraint group to only affect the distance and bend constraints (on the vellum rest blend dop node). This prevents any other constraints like the pin constraints from being affected. On the pin constraints, you can set orientation to none, that only affects hair. lower the stiffness amount. Then you will see it is now working. However, I would still use the method that kevin provided for this instance. However, the example I provided may be better in other scenarios (like the shot I am currently working on).

hope this helps someone else in the future.