nParticles Concentrated Streams?

[andymc4997]

Hey everyone, I'm trying to recreate this shower head spray with nParticles (if Bifrost is better, I'm all ears):

I've went through a bunch of settings, and nothing seems to get me quite there. Without creating either a bunch of emitters, or colliders, is there any way to achieve this effect with a single emitter? 

Thanks in advance!

[mspeer · Accepted solution]

Hi!

I recommend to try

nParticles > Emit from object.

Just make sure to create a polygon object with the vertices at the desired position and choose an appropriate Emitter Type.

[andymc4997]

Awesome, @mspeer, thank you!

I tried then converting my particles to polygons, but the performance was really slow. I will probably just render the particles as-is. 

Now I'm trying to add a bit of motion blur with Arnold to get a more realistic spray effect, but the nParticles are taking a really long time to render with CPU (I need to use CPU because the client of course wants transparency for the water). My simulation is only 80 frames. Is this common with Arnold motion blur?

[andymc4997]

Ok here's what I have, just using Photoshop's path blur/masking/layering instead of waiting ages for motion blur to render with nParticles:

[sepu6]

Bifrost will be faster and better for all kinds of FX nowadays in Maya. 

But I am glad that you found a solution

[mspeer]

Hi @andymc4997 !

There are many options how to create and render water. You can render points, instanced objects and also create a single mesh. It all depends on your needs and the look you want to achieve.

However in the current case using simple points or instanced modeled droplets / splashes should be the easiest option. I also would add the blur in post, as rendering this in 3D would drastically increase the render time. (Of course this also depends on the shutter time you want to simulate.) It seems you already found the best option.

I have to admit that Bifrost is faster for the calculations and is much more versatile, but for small and simple projects nParticles can overall be the faster approach, because they are quick and easy to set up.

[andymc4997]

Ok @mspeer thank you!

I'm now having to create many different spray patterns for this shower head (of course lol), and yeah especially for a Bifrost newbie, all of the settings can be overwhelming, so I might stick with nParticles.

So.. I can create pretty much every pattern now except the first one here:

I think the solution may be either using a Volume Curve or Volume Axis field, or a combo of both. I'd appreciate any insight on this as well. I'm gonna make things easy for me by rendering a single stream 3 times, and creating the various spray affects in Photoshop. Of course the "Pause" version will be a different emitter and should be pretty straightforward as well. 

[mspeer]

Hi!

Maybe I would model the part near the showerhead that looks like a bell and use particles only for the rest of the streams.

Then there still could work a directional emitter (you may need more vertices per stream to get a small area) in combination with spread. By using Min Distance and Max Distance for the emitter you could blend from the modeled bell part into the streams.

Just in idea, not sure if this works or if this would be easy to set up.

Here a very quick example that shows what I mean:

[andymc4997]

Well, we are back to this project again, after I thought I had found a solution. The client was happy with my shower head renders... (one example, and the unnatural blue color was their idea, lol)

...but then they found one that they say looks "sharper":

They are correct, but as so often happens, they are simply unaware of how technically demanding such high-poly water streams would be to create and render, especially with nparticles. To achieve such a smooth-looking sim, we are talking particle rates into the tens of thousands, correct? Should I lay nparticles aside and jump down the Bifrost rabbit hole at this point? What suggestions might you all have to achieve this look without having to stare at my screen for 15 minutes at a time while making adjustments? 

[damaggio]

Are you generating animations or still images?

[andymc4997]

Stills

[damaggio]

In that case is much easier to model the water that shoots straight and only sim the ones that look more like a spray.

[damaggio]

You can do it with a ramp or texture and a displacement, just do some IPR tests.

The misty spray there's no way around it, gotta be simmed one way or another.

[sepu6 · Accepted solution]

If you are doing stills, then it should be a lot easier, for those straight lines you can use a sweep. 

For the spray around there is no need for a sim just scatter pts around the lines basically, spread them apart and apply a noise to those pts. 

[andymc4997]

Ok, after reading through all of your posts (thanks by the way), I think I might be able do this with MASH water droplet instances following curves (which could of course be animated if I really wanted to), and then yes, using the same curves with sweeps and noise displacement!