hello,

I'm playing with wire solver. I'm trying to make wires to stick to emitter surface, but gradually. Ideally, I'd be able to have hair part close to root, to absolutely follow the emitter deformation - or deformation of any other wire object, having the same point structure. Hair tip should be affected only by simulation.

For now, got something close, by creating a target stiffness attribute in VOPSOP on static object, varying by point. But, this procedure doesn't seem to work with pin constraint. Let's say if I set ‘restlength’ attribute on static object, nothing changes.

In Syflex for Softimage, even old, non ICE Syflex, I'm able to paint the weight map, and use weight map for modulating the pin or mimic constraint. So, no big deal to have a portion that sticks absolutely, together with *smooth* transition to absolutely simulated part.

In ICE simulated tree, I'm able to just set point position, using value transferred form anywhere, and mix this with simulated result, using a plain linear interpolate node ( I think this is a mix in Houdini). How to do to this in Houdini… Tried the blend solver, to mix the wire solver with static solver, but didn't get anything more than network without errors and no blending at all - I must be doing something wrong, obviously….

Ok, finally I got Blend Solver to work. Stubbornly, I kept the Blend Data name to ‘position’, which seems to be SRT in Houdini, so nothing happens as both solvers are at world origin ( that's how I understand…). By setting Blend Data name to ‘Geometry’, or , deformation in Softimage, it started to work. Not exactly what I wanted, but more than enough to forget to Syflex style constraint weighting. All good.

amm
Ok, finally I got Blend Solver to work. Stubbornly, I kept the Blend Data name to ‘position’, which seems to be SRT in Houdini, so nothing happens as both solvers are at world origin ( that's how I understand…). By setting Blend Data name to ‘Geometry’, or , deformation in Softimage, it started to work. Not exactly what I wanted, but more than enough to forget to Syflex style constraint weighting. All good.

Hi,
Can you post the .hipnc file so we can learn what have you done to solve the issue?
Thank you,
C

Constantin X
Can you post the .hipnc file so we can learn what have you done to solve the issue?

Well scene is a bit messy….
Basically, I just copied the blending structure from factory “SimpleBlend” sample, then pasted it into Wire DOP network, created by shelf tools. And forgot that mentioned “SimpleBlend” operates with SRT (position in Houdini), not deformation (geometry in Houdini).
Anyway, it looks like in pic. First on left side does the “all in all” blend, driven by animated ‘Blend Factor’ parameter. At some point, entire simulation is blended back to original shape.

Second on right side is more ICE-ish setup, where Geometry VOP smoothly blends the Wire solver, against another geometry with same number of points ( this time, just an original geometry) - what we call ‘switch context’ method in ICE, or Shape Key. So, ‘mix’ node in geometry VOP acts as a sort of per-point constraint, having any weight between 0 and 1, anywhere.
From my tests, second is about 20 percents slower than plain wire simulation - but it does what it does. It can live without “wire glue” constraint.
In third pic there's Geometry VOP - at bottom, there is structure, similar to internals of ICE ‘Build Linearly Interpolated Array“ - it does re mapping of hair points, from per-hair point count, to 0 - 1 range. Two ”get attributes“ gets the P and v from external object - not sure is there a real need for connecting anything else than P, maybe v.

Theoretically, same setup should work for Cloth sim - but don’t hold me on anything, everything here is purely experimental. Note that it is always possible to blend in ”post-simulation" by adding something after DOP Import on original object - but, this is less natural, definitively.

amm
Well scene is a bit messy….
Basically, I just copied the blending structure from factory “SimpleBlend” sample, then pasted it into Wire DOP network, created by shelf tools. And forgot that mentioned “SimpleBlend” operates with SRT (position in Houdini), not deformation (geometry in Houdini).
Anyway, it looks like in pic. First on left side does the “all in all” blend, driven by animated ‘Blend Factor’ parameter. At some point, entire simulation is blended back to original shape….

Thank you.