wetmap looks spotty

[japetus]

How would I go about getting more particles to get more detail in my wetmap? I have a blood scene, ala, The Shining trailer (all for fun) where blood comes out of a doorway and splashes on the walls. I'm pleased with the liquid of my sim...but my wetmap seems spotted. I tried increasing the blend radius, which just makes it more blurry and undefined. I'm using a PHXFoam for my foam and splashes, should I be using one for my wetmap also even though it shows up w/o it? Thanks!

[japetus]

Here's a good view of what I mean if it helps...

[Guest]

Hi,
may be the grid resolution is too low. Try to increase it. Also, try with the options in ParticleTexture.

[japetus]

What settings in the Particle Texture would you suggest? There don't seem to be any that would help. I am Resimulating just the wet map with a smaller grid and more steps, so we'll see if that helps!

[japetus]

Ugh, I'm trying to resimulate and I'm having some issues. I changed my Input path to read my sim i already made, and changed the output to have "-resim"...byt then I discovered that my wetmap particles had no velocity, and I got an error on the resim telling me as much. When I go to the output settings to turn on Velocity for my wetmap it's grayed out and I can't figure out how to get it to turn on! What's going on?

[Svetlin.Nikolov]

Hello,

Using the Liquid simulator you don't need to change any paths before resimulating - the original simulation files will be overwritten. If you need those anyway, say for a reference, you should backup them manually. We have to change that in the future..

Regarding wetmap velocity - since the wetmap particles are always stuck to the surface of the wet geometry, they don't actually have velocity. Are you sure the error message was about the wetmap particles, or the liquid grid (note that in the Output panel there is velocity for the individual particle systems, and there is also velocity for the grid). This could also be caused by changing the paths - if the re-simulation can't find the caches, it would complain about missing files or missing grid velocity.

Cheers,

[japetus]

Hmm well I must be doing something wrong. The first time I tried resimulating, I didn't change any paths. I turned on Resimulation, unchecked splash and foam, leaving Wetting on. I increased the grid resolution a couple times and started the sim, it started going fine, but then after the first frame was calculated my grid shrunk to like 2/3 the size as before, like the world had shrunk (because of the smaller grid size I would imagine) which was unexpected. Am I doing something wrong here? I didn't let it go very far because I thought that was strange behavior. That's when I started changing input/output paths to not save over the old sim.

[Svetlin.Nikolov]

Ah, then this is it - you should not change the grid resolution between simulation and resimulation. The liquid resimulation right now cannot upres the simulation - it's something we still need to implement.

[japetus]

Oh ok, so if I wanted to get better wetmap detail I'd have to simulate it all again? Bah! Thanks, good to know!

[japetus]

So I turned off my wetmap for now, except for the end, I don't think I can get enough resolution. My sim files are getting up to 200 MB each near the end of the animation, and it sorta crashed itself about 2/3 of the way in, ran out of memory I think, but didn't exit, just stopped simming because of the error. I am simming to my Raid and there is plenty of space, so not sure what happened there. But I was more curious about how to get rid of the little bits of water flying ahead of my sim....they look like ball bearings! Is it just a matter of reslution? I'm not sure I can go much higher in cell count! Here's a link to the video: http://www.japetusproductions.com/Im...dwatersim1.mp4

[Guest]

Hi,

pretty interesting simulation! So, can't tell what's causing it. You can watch the memory usage in the task manager. Even If you run out of memory it shouldn't crash.
The "ball bearing" problem is caused by lack of sticky effect. That's why droplets are moving freely everywhere. Viscosity and Surface tension are the key parameters for liquid dynamics. Increasing surface tension would make liquid harder to spread to thousand droplets but would not limit its mobility. Increasing viscosity on the other hand would make liquid thicker. So, play with that options and I hope you'd get the final look you want.

Cheerz!

[Svetlin.Nikolov]

Yup, most importantly enable wetting, and either enable sticky and add some small viscosity, or set Consumed Liquid to a value above zero, so these particles would be absorbed by the collision geometries.

[flat]

Does Chaos present a solution for spotty?

I requested a fadeout function to VRayDistanceTex.

https://forums.chaosgroup.com/forum/...ishlist/954889

[Svetlin.Nikolov]

Does Chaos present a solution for spotty?

Depends on the scene, but in general - make sure you have consumed liquid above zero, so one particle would not create an infinitely long streak over the geometry surface, use high resolution and play with the settings of the Particle Tex - the particle sizes and blending modes.

[japetus]

Thanks guys! My sticky effect and surface tension were indeed set to 0...so i've adjusted them to 0.1 to see. I've also set viscosity to 0.1 and consumed liquid was already at 0.1. Hopefully I'll get a more pleasing result!