How to drive blendshape with a spherical influence?

[mostly_human]

I am wanting to basically drive a blendshape using a "control sphere", if the blendshape is outside of the sphere its envelope stays at 0 but if it inside the sphere's influence then the envelope will be driven by how close to the center of the sphere those vertices are (so if its at the center of the sphere it will be max envelope influence then falling off to the edge of the sphere).  Hope this makes sense and specifics are greatly appreciated!!

[lee.dunham]

I'm a little unsure what exactly you're after.

Changing the weight of the blendshape based on a distance to another object is easy enough using the distanceBetween and condition nodes.

If you want to change the weight of the blendshape for each vertex based on distance, it's quite abit trickier, but I think it's doable

[BenediZ]

Hi there, same question here:

How can I drive a blendshape based on vertices just by distance of a (control) sphere?

(I guess with influencing a weight map somehow, but did not find out how)

Thanks for advice!

[lee.dunham]

I think a custom deformer is worth looking at depending on the number of verts you need to drive.

I haven't tried this but from what I'm aware of the weights are stored per vertex on the deformer in an array.

Modifying them based on a distance is doable but slow unless it's done via custom deformer (plugin).

[BenediZ]

thanks, I found today a plugin called „Shape“ (see below)

I will test this as this seems more versatile than own solutions. 

I know from vray that there are distance maps, and thought they could somehow drive the paint weights. but I found no documentation. 

http://www.braverabbit.com/shapes/video-documentation-blend-shape-weights/#weightsServer