Just wondering if it's possible to apply a force to this cloth based on the normals of the sphere object behind it? I cant seem to find a force that might work based on the mesh shape. Also the object won't always be sphere shaped so I can't use a basic force to achieve the same results.
Hehe, Yes I see what you mean I was thinking something a little less solid than an actual collision. Is it possible to effect cloth with a particle system, maybe a velocity field?
I think a sop solver is the way to go and gives you the most flexibility. You just need to transfer the force ( or normals ) from the sphere to the cloth. You can also do some fancy pressure / underpressure imitation if you have a closed cloth object and use it's own normals as force.
Esteban Diacono Hello! the hip files doesn't seem to work in H16. It would be interesting to see how this works. Thanks!
I think the stiffness/density constants in 16 may have changed. Multiplying the force in the sop solver 50-100x seems to bring the deflate/inflate behavior back again.
in a lot of H16 and 16.5 builds, the v@force and v@fexternal attributes are not working with Cloth to test it make sure you have the latest version
https://www.sidefx.com/changelog/?version=16.5.425&show_versions=on Houdini 16.5.425 Restored backward compatibility of the finite element solver for simulations that are set up with the point attributes “external” and “force”.
There is an disadvantage of houdini that some scenes do not work with H16 and subversion of H16 (see above) that's why I'm looking for a tool which can convert the scene from different versions.
tamte in a lot of H16 and 16.5 builds, the v@force and v@fexternal attributes are not working with Cloth to test it make sure you have the latest version
https://www.sidefx.com/changelog/?version=16.5.425&show_versions=on Houdini 16.5.425 Restored backward compatibility of the finite element solver for simulations that are set up with the point attributes “external” and “force”.
If ‘force’ is the old name for backwards compatibility, what is the new name? It's not published anywhere. The documents still state force and fexternal are the attribute names used for imparting force-per-point, although they do recommend using targetP instead of force/fexternal. Maybe they dropped support by accident. Personally I find framing things in terms of targetP unintuitive, and goes against the spirit of simulation. If you define the system in terms of differential equations, then targetP itself must be solved, and that's the solver's job, not the artist's.
That's exact purpose though, so you can affect the simulation with animation.
the point is to have both types of control, not to always use targetP instead of force, both have their specific use cases
otherwise good luck affecting cloth without custom forces
jsmack If ‘force’ is the old name for backwards compatibility, what is the new name?
I didn't realize that the journal entry really sounds like force for FEM is deprecated, I hope it's just a bad wording choice, force is so crucial to do anything
That's exact purpose though, so you can affect the simulation with animation.
For controlling simulations using animation, of course it makes sense to use targetP, in this situation it is ‘known.’ I am referring to scenes where you don't really have a target position, you merely want to impart forces, such as pressure or gravity, without having them cancel each other out when the target stiffness is increased.
fuos So is there anyway in dops to do some force vector calculations to make this happen?
just create ‘force’ vector point attribute using any POP force nodes or custom ones as you see at the beginning of this post, ‘force’ attribute (or even the old one ‘fexternal’) used to work fine, but then was broken around H16-16.5, and the support for ‘force’ have been restored in recent builds (the discussion here was that the wording in journals sounds like it was restored for backward compatibility and not as fixing the bug so it just sounds strange, but no matter what it should work now once more)
