hey friends
i want to ask that how i create shape(skull) from a smoke(cigarette smoke) ,i try many things but can not make so can anybody help me regarding this

Was watching this course the other day may help you out:

https://app.pluralsight.com/library/courses/disintegration-teleportation-reintegration-effects-houdini-2322/table-of-contents [app.pluralsight.com]

One of the BEST videos you can ever watch is by Steve Knipping Dynamics course. It is available over at CGCIRCUIT.COM. KNIPPING HAS A master in Computer Graphics Enginnering. Houdini can have a steep learning curve, and I have a Computer Science degree as well. Steves videos bring a production level of quality unseen in other videos.

The first video is free and has TONS of great stuff.

Purchase the rest and you will have learned from the guy behind some awesome effects in Star Wars and others.

I have watch TONS of Houdini and read everything I can get my hands on. This is by far the VERY BEST one I have watched.

Next is Pluralsight. $29 a month gets you AWESOME Houdini training. Some are outdated and you have to extrapolate Houdini 15.5 functionality.

Intro to Houdini 15 on PluralSight is VERY WELL DONE.

this might help as well.
http://www.iamag.co/features/geometry-based-vectorfield-shaping-for-smoke-simulations/ [iamag.co]

THANKS FOR THE HELP I WILL TRY THESE