07-31-2021, 08:10 PM (This post was last modified: 07-31-2021, 08:22 PM by shirogtr.)
Hello,
In some other thread I've read its very easy to render a simple - cigarette like - smoke with tyFlow only (without using Phoenix FD).
Ive done some reasearch and experimentation without any success. Ive tried exporting my particles to a .VDB sequence and rendering them with Vray.
The result was far from satisfactory. Smoke looked like little clumps, and not like smooth cigarette smoke.
Does anyone know how to pull this off with tyFlow only?
No Krakatoa, or any other fancy software...
Attaching the file too.
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The way that people did it back in the day (when fluid simulations were not present), is that you create very small particles (maybe even with little opacity), spawn them all the time, and drive them with some wind and turbulence.
The more particles you have, the less size of them (individually), they will look more detailed and cleaner.
Motion Blur plays a BIG role in this effect, because it nicely blurs all these small dots, creating an illusion of thin smoke.
(I've added MB in post, in my example).
Attaching the file too.
--------------------------
The way that people did it back in the day (when fluid simulations were not present), is that you create very small particles (maybe even with little opacity), spawn them all the time, and drive them with some wind and turbulence.
The more particles you have, the less size of them (individually), they will look more detailed and cleaner.
Motion Blur plays a BIG role in this effect, because it nicely blurs all these small dots, creating an illusion of thin smoke.
(I've added MB in post, in my example).
Hey,
You achieved a very realistic smoke swirl effect!! This is what I've been doing as a workaround. I'd render lots of small particles with VrayVelocity pass and add Vector Motion Blur effect in Resolve Fusion afterwards. Unfortunately it doesn't produce 100% smooth smoke.
My focus was mainly on the rendering methods. I was hoping to achieve effect similliar to the thummbnail image of this video: https://www.youtube.com/watch?v=0CoIA9l5yxo
Unfortunately Allan did not show how he rendered the particles.
The other problem I have with this method is particles dissapearing. No matter how hard I try, I cant get material opacity to work with tyFlow.
What I would do as a workaround is:
1. Add a delete operator based on particle age.
2. Add a Scale operator decreasing particle size within their lifespan, with a small interpolation value (something like 0,04)
This method is still far from perfect, because the particles always decrease their size too fast, resulting in them dissapearing rapidly.
You can achieve it vray too if you're using light material, and throw in there some opacity.
But on my comp it was always waaaay too slow.
Alternatively, you don't need to render additive mode, but regular, and then in post just clone particle pass and set it to screen or add blending mode.
You can achieve it vray too if you're using light material, and throw in there some opacity.
But on my comp it was always waaaay too slow.
Alternatively, you don't need to render additive mode, but regular, and then in post just clone particle pass and set it to screen or add blending mode.
now.. it might be that I totally misunderstood you.. in that case.. sorry
Your results are phenomenal! This is the quality I was hoping to achieve.Thank you
I never thought of using Scanline renderer (hardstuck in Vray for 10 years). I will experiment a bit more in my free time with Scanline and Vray.
Vray can be a bitch when it comes to cranking up max reflection/refraction parameter.
Thanks.
The effect is really simple, and I'll leave now some more info on what is causing it, and how easily to achieve it, for anyone interested
I did now 2 simple boxes (look attachment) in scanline, and one stands behind other.
I applied the standard material,, blue color lowered the opacity, and increased the self-illumination a little bit.
And MOST importantly, under extended parameter, I switched from filter to "additive".
What does additive do?
Well, if you look carefully in the picture, where the boxes are overlapping, it's actually brighter, not dimmer (like it should be in some "real case scenario").
That's what additive mode in scanline means.. if you switch it back to "filter", it will be darker where boxes overlaps.
Now, if you have ton's of little boxes (particles), swirling around, and turn on that additive mode, you'll get same result as that Allan McKay image,
You could get pretty much same effect in Vray if you're using light material, and turn opacity lower, but as I say before, whenever I tried it, it was waaay too slow (even without GI).. basically I am very unhappy how vray handles transparency, either in this case, or in case of leaves textures, or stuff like that.
I've tried RedShift demo, and it did it 50 times faster, so I bought RedShift... I don't want.. nor care to advertise them.. but it's really 50 to 100 times faster for the stuff I need.
But then again, you can render regular self-illuminated pass of particles (without opacity (either in scanline, Vray, RedShift.. etc), and very easily, in any compositing app, clone that particle pass, switch to "screen" blending mode, and you'll get the pretty same effect.
The simple test I did above are all just straight scanline renders, and done with Particle flow, that can use very cheap and fast, scanline image motion blur.
Unfortunately, Tyflow still don't support cheap scanline image motion blur... it supports it.. but only if the particle meshes are constant.. not if they are born over time.
I know you mentioned no other software but there is a useful trick for speeding up rendering of point clouds (or just about anything really) and getting a smoother result. If you're renderer is rendering them as dots and is tied to you're resolution like Krakatoa is, you can render your frame at a lower resolution and then use an AI up-scaler to increase to full res. It is great if you need a smooth result without seeing individual dots. I used gigapixel from topaz.
Its no substitute for more particles of course, but it certainly helps when you starting getting highly diminished returns when adding more particles. It can also help smooth things out due to the adjustable filtering settings. Combining it with a motion blurred result can smooth things even more. I used it on this ink sim i did awhile ago. https://youtu.be/olkgrqRrUic
