Hi,

I was wondering if anyone could suggest an efficient way to create a hovering “dry ice” type of fog effect in Houdini. Here's an example of what I'd like to achieve:

http://www.youtube.com/watch?v=hsLoI_17ncU&NR=1 [youtube.com]

I'm assuming that this could be done using a volumetric smoke container but I'm wondering what the trick is to keeping the fog from dispersing while still having a fluid motion.

I was also messing with the sprite fog shader using particles but I couldn't figure out the proper way to use it.

Thanks for your help!

Nick

Does anyone happen to have a suggestion for achieving this look in Houdini? Does using sprites sound like the most efficient way to tackle this? Is there an online tutorial about using sprites?

Thanks!

Nick

How about a fog volume with some noise applied

Rob

Rob,

How would you recommend adding the noise? I've tried adding noise to the geo using a moutain sop (creating an ocean type of noise effect) and it seems to be working but should I be adding it somewhere within my dop network or to the material somehow… any suggestions?

Also, how does one keep from having the volume disperse? I made the bounding smoke box smaller and it seems to be holding it together. Is this how you would recommend doing it?

lastly, what is the recommended way of controlling the opacity of a simulation like this?

I've attached an example of where I'm at…

Thanks for your help!

Hi,
You should be looking at the basic videos on fluids and volumes found on this websites learning section.

rob

According to a dry ice [http] website, dry ice fog can be created easily. All it takes is water and dry ice. The dry ice fog will last for a while (until it has warmed up). Because the composition of the dry ice fog is heavier than water, it will stay low to the ground. This gives a great effect.

How about this?

The trick is to prevent the fluid from dissipating. So, adding small amounts, reducing diffusion, adding noise continously, trying to keep it “down” will all help.

Here's my quick attempt.

I built a Volume VOP to add noise to the smoke emitter SOP network added by the shelf when I used the Smoke From Object tool.
Cranked up the source volume resolution to 100 in the max dimension in the smoke emitter SOP network.
Removed all boyancy and diffusion hammered to 1.
Added vorticles from the shelf and a bit of vortex confinemet to get some swirls.