Billowy smoke - adjust look after sim?

[cwalrus]

Hey there- 

 

Dragster, burning tires, animation looks COOL. However, the viewport looks perfect, while the render looks way too thick, dark, and detailed. See images below.

 

I've ouput the sim already as well - is there any way to adjust the look without re-simming? I had planned to do it with a shader after the sim, but maybe I'm restricted at this point...

 

also, any tips on getting it to look like the viewport image? less detailed, more transparent, even white, etc...

 

THANKS!
 

EDIT - I should point out that I want to adjust the transparency / density, but if I put a basicSmoke shader on the geo, adjusting the Smoke Density seems to create wonky results, and doesn't work correctly.

Edited November 3, 2015 by cwalrus

[fathom]

density and shadow density.  density will make things more transparent and shadow density will reduce the contrast in your shadows.  shadow density is a multiplier on your normal density for the purpose of calculating opacity along the light ray.  so 1.0 is the same as your opacity.  if you drop that, you'll get more light passing thru your smoke without having to make it commensurately more transparent to camera rays.

 

those are pretty much your only options.  oh, and also your smoke intensity of course will make it brighter or darker without affecting the transparency.

[cwalrus]

Thanks mate- yeah as I said, I know it's the density- My main question is, do I need to re-sim it to adjust the density, or can I adjust it post-sim via a shader, and if so, how?

 

What's a good workflow for smoke sims - getting the entire look right out of the sim, or baking the sim and then applying a shader?

 

i.e. Let's say I let it sim for 50 frames - do I seriously have to re-sim the entire thing just to see it slightly less dense?

 

thanks!

Edited November 3, 2015 by cwalrus

[fathom]

you don't need to resim to adjust the density.  not sure why it looked wonky in your setup, but having a 0.01 density in your shader is perfectly fine.  there's no real scale to density, as far as i can tell, so one sim might have a very high density depending on how it was created while another created in a different way might have a fraction of the density.  but density doesn't tend to change the look of the actual sim too much (in terms of the dynamics) so shader-time adjustments are all part of the game.

 

you can also do additional sop adjustments like volume blurs to change the look without having to re-sim.

[old school]

Just think of density as a mask from 0-1. You can remap the density at render time with the smoke type shaders or the pyro shader to whatever range you want.