Smoke Column

Started by otakar, August 16, 2012, 04:35:19 pm

Previous topic - Next topic

otakar

Dune mentioned the desire for a procedural smoke plume (for the Medieval City project), so I thought I'd have a go at it. Attached is a sample render with network view and a clip. Plug this into your atmosphere chain - the smoke node is nothing but a cloud layer.

The explanation is simple, the density fractal is constrained by a simple shader so only a vertical column results. That column is then redirected along the x and y axes for some variation. I am further constraining the size of the layer via the Localise options so that the plume does not extend forever (in both directions).

The tricky part here is the alignment of the plume with the source (e.g. fire or chimney). The warper moves the plume around so that you either have to move the underlying object or mask or exercise your patience and keep hitting the seed button on the powerfractal node until it aligns. It would be great if some more precise configuration could be constructed.

The other issue I have with this is while IMHO the result is quite acceptable, for it to look smooth you need to drive up the sample count on both the atmosphere and cloud layer node way high (even with RT on). Render time of course suffers. If someone can revise this and come up with a more efficient setup it would be wonderful. Every time I tried to speed things up the smoke just got grainier.

So, while this can certainly be improved, it is a start. I would not want to use this same setup a dozen times for a village scene (exact placement would be quite a nightmare) but adding it once or twice in a scene should be doable without too much effort. Whaddya think?


Dune

That's a good solution, Otakar. Thanks for bringing it up. I did use setups like that previously and in the mentioning of procedural smoke in the medieval city project I was 'hoping' for a simple point and click system. Like, whenever you click a certain area a soft circle is there, which acts as a placeholder for a cloud column. In fact I don't really know why I said it, as the principle is indeed not too hard. You may recall me asking for a soft, cone shaped column some time ago. The setup of hundreds of columns however, as you say, is quite tiresome, hence the hypothetical 'point and click' system.

By the way, you won't need the link from the PF to the input of the redirect shader (IMO). To restrict the warping you might add a surface shader under the redirecter, and blend that by a distribution shader, so the warping of the column only starts softly above the ground point.

Thanks, Otakar!

lat 64

August 19, 2012, 03:38:45 pm #2 Last Edit: August 20, 2012, 10:39:53 pm by lat 64
Love it!
I am working on a camping scene for a book cover.  This is great timing.
I tested it in a new file first. I had some operator error as I was just too far away to see it in the default-file render ::). I zoomed in and there it was.

I plugged it into the input at the atmosphere 01 node ; Voila!

Thank you for sharing,
Russ

(An update for any Noobs like me out there trying to make this work:
to reposition the smoke you must paste x,y,z, co-ordinates in both the "smoke"(cloud layer V2) centre, and the "column size"(simple shape shader) position. At least... I think that's right???.
r.
I'm a half century plus ten yrs old. Yikes!

bobbystahr

damn cool man...getting caught up on my reading and just found this.....thank you..  ...
something borrowed,
something Blue.
Ring out the Old.
Bring in the New
Bobby Stahr, Paracosmologist

lat 64

This is how it rolled.
Since then I have learned so much, but you have to move on.

It did make the camping scene a tad more real.

I'm a half century plus ten yrs old. Yikes!

choronr

Thanks otakar and Dune, appreciate the file and will enjoy trying the procedure.