Contraction of pupil through shader - radial stretch?

[Zruud]

Hi,
I would like to rig eye pupil contraction without bones or shapekeys - is there shader setup to stretch texture from certain point to center please?

[Okidoki]

You mean something like this ?:

[Zruud]

No, that example shows scaling the whole texture, I need this effect:

Pupil reactions [HD]

I found some videos for procedural textures, but I need it for hand painted texture.

[Okidoki]

Ohh… yes… no “i see” …

[Zebrahead]

Hi,
you could try this:

[Debuk]

I this is a very simple effect. My solution is going the same way as Zebraheads. You shift the center of the image to 0,0 sample nonlinear and then move the samples back to the initial range.

[Secrop]

You could do this just by transforming the UV coordinates.
It will depend on your current UV layout, but it’s doable:

just playing around with those nodes in green…

[Zruud]

Thank you all, I’ll try your methods