It's a little misleading, but delete the pieces that have a zero volume before you sim. You can use a measure sop in a for each sop, to get the volume of each piece. Note that some pieces may be treated as static, even if their volume is greater than 0. If you want to know exactly which ones, after your sim group points with length(v) == 0 (The static pieces) then you can see what their class/name is and delete them before the sim that way

I opened a H19.5 scene that I was working on last night, and in the morning, most of the nodes had a red lock next to them that was unlocked, as if they became a digital asset overnight. Anyone ever experience something like this?

That worked absolutely perfectly! Ill try and dissect what u did and give it a shot. Thanks again!

Hi there, Im struggling with something that should hopefully not be too difficult for someone with more vex knowledge. Ive uploaded a hip of a simple scene, where I have points around a curve. I want the points to orbit around the curve, but maintain their distance. A pop curve force wasn't really working out, and I can't use a pop axis force, so I assumed vex would be the best answer. Any help would be appreciated!

Thanks!

Thanks for the response! While the shape changes a bit, the biggest change I see is in the temperature and density that is output. I can probably refit the temperature, but the density is a bigger issue. Good to know it isn't a simple fix that I was just missing.

The specific issue im having is that im getting horizontal lines in my pyro, which I believe are a result of the collision object. I wish there was something like collision iterations for Pyro, because substeps appear to be the only thing that improves it.

I know that if I increase the substeps, certain solvers inside the pyro solver calculate extra times for each substep, changing the look of my sim. Anyone know a work around, or which attributes are affected by the change? I have a sim that I need to resolve artifacts with by using substeps, but increase the substeps changes the look! Any insight would be much appreciated!

Substeps appear to fix the problem

I believe the mat context is more like vops, in that we have the ability to edit shaders at the top level. Whereas with shops, you need to dive inside to access the attributes. Shouldnt be a huge difference, but id suggest getting use to having your materials in the mat context

I was struggling to find how to achieve convergence with flip. After enabling Divergence by attribute on the solver, I created a divergence attribute in sops and had it inherited into the source, then divergence appeared to work. To get convergence, which aids the stringy tendril look for the fluids, I had to use a negative divergence value, which gave me exactly what I wanted.

Also, if your cloth has a low enough bend stiffness, it will naturally create wrinkles due to gravity. Then you need to balance it by adding stiffness. If you need additional wrinkles, they can also be added post sim, using the vellum brush. You might need to write out the sim first.

I dont have time to dive into a hip rn, but Id suggest experimenting with your pscale value, changing your lighting setup, trying a constant shader to see if that works, etc. If none of that works, I can check out your hip later

There's a few methods. If there is enough topology, and the cloth has a low enough bend stiffness, it will naturally wrinkle. Then compression stiffness can help preserve those wrinkles.

Also, the vellum brush is a good way to add wrinkles as well. I used that on an animated alembic, to add wrinkles to that. Can potentially use that on a static alembic, then set the wrinkled geo as the new rest state. The cool thing about the vellum brush, is it supports collisions, so that we can avoid the interpenetration we would normally get when shaping the cloth on the body

Anyone have any tips. I have a shirt that Im simming, and I'd like to be able to force some wrinkles in it. As far as I know, using a high compression stiffness is what is supposed to achieve that, but Im not making much progress by changing that parameter. Any tips would be appreciated.

I have a dress sim I am working on, and the model of the dress has a part folded up and "pinned" at the bottom, so its almost overlapping the other side of the dress. The issue Im having is, as soon as my sim starts, the folds that are so close together interpenetrate. Im not certain if I should use using a one sided model, or a way to work around these fine folds that need to be simmed. Ultimately, Im getting failed self collisions, and increasing the thickness isn't making a difference.

Anyone have any ideas?

Thanks!

Sorry no HIP I can share

Here's a hip file where I tested with collisions, without collisions, and with collision vel. Even with my collision vel set to 0, we still get full velocity from the collisions. If I understand collisionvel correctly, it only happens when the fluid contacts the collision geometry. Since my collision geo is inside the source, thats my entire sim. We need collisions in order to have a collision vel, so how can I dampen the amount of velocity we are receiving from collisions?

Okay, after breaking down what's happening, I believe what I'm actually seeing is too much collision velocity. The collisions with the smoke is what is causing the look of inherited velocity, and without collisions, it isn't a problem. I believe that's why my workaround was dampening the movement of the alembic so we didn't get as much "collision velocity" for lack of a better term. I've attached a hip file where I'm able to scale the translation of the alembic, sim, then add that translation back. Ultimately what I need to do next, if possible, is scale the rotations as well, so that they remain in the right location/axis. The head turning alembic example I gave you is a good example of how, despite having essentially no translation, we still get the head twisting in each direction, pushing smoke further than I'd like. If I could get a channel for that rotation, scale the rotation down, then re-apply it, I'd be able to limit the "collision velocity" of any alembic I receive. Any help would be appreciated!

There's a type of inherited velocity from the movement of geometry, that can't be scaled by simply multiplying the velocity on the geometry before it goes into a sim. Ultimately what I want to do is be able to read the rotations off an alembic, scale them down, then re-apply them (post sim). That way, if my alembic is a head turning that turns very fast, I can dampen the amplitude of rotation, sim, and then apply the rotation back after the sim.

I was already able to grab the pivot for the intrinsic attributes, scale that down in chops, and reapply it. That took care of the translations. The rotations are more complex though.

I've seen some posts on the forum regarding this, but I can't seem to get anything working regarding this.

I have an alembic, and I want to be able to extract the intrinsic rotations on the alembic, scale them down, then use that new channel to apply the scaled rotations to the original alembic. This should be able to work with translations as well.

Ultimately, Im trying to reduce the inherited velocity from an alembic, so reducing the movement of the alembic itself is my only option at the moment. If anyone can provide a sample file, or have advice, it would be much appreciated!

Im working on an animation, and Im using a basic liquid shader to shade my ice. Im getting a bright specular highlight that looks like a firefly from a sun light in my scene, and I can't find the right combination of render settings to eliminate it. Any render settings or shader tips that might help me resolve the problem?