FumeFX opacity over life

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

Thread Tools Display Modes
  09 September 2012
FumeFX opacity over life

Hey there,

I'm back with another FumeFX question I hope you can help me with. I've got this animated cow object that's emitting only smoke via Object Src. It's pretty dense smoke and this makes the cow way too tactile, so I'd like to make the smoke 'fade in' over a couple of frames, rather than 'being there' right away. Ideally, controlling the opacity of the smoke based on the particle age.
I tried using the opacity AFC to do this, and I tried putting a Particle Age map into the Smoke Opacity slot (and simulate with fluid mapping on) but that didn't work.

Have you got any suggestions how I could make this work?
Attached Images
File Type: jpg FumeFX_Cow.jpg (17.8 KB, 26 views)
  09 September 2012
I'm not sure if this is what you're after or not but I solved this in a recent job by using a black and white map I made in After Effects to control the smoke. The map was essentially complete black with white text that faded in and had some animated black noise to break it up. I threw that map into the temperature slot, the smoke/fuel slot and pretty much everywhere else that would take it (I can't remember the name of the tab but it's the furthest right one I think in the Fume UI.)

Worked a charm
Steven Olver - 3D and motion graphics artist in the UK
  09 September 2012
Hey Fresh, thanks for taking the time to reply.

If I understand you correctly, you used the black and white map to make the smokey text appear out of nothing.

The thing here is, I really want to use the 3d cow to do this, and I want it to emit smoke constantly, only when the smoke is emitted, the smoke 'particles' themselves should fade in, rather than 'pop up'. Because I really like the look of the smoke a few frames after it's been created, but the first couple of frames it looks like bubbles popping up.

Is there no way to control the density or the opacity of the smoke, based on when it was spawned?
  09 September 2012
The only control you may have in this manner is by using the smoke opacity AFC curve, you can simply "fade" out the near birth (the far right side set to 0.0), add a point in the middle somewhere, and the oldest value (the far left of the AFC also set to 0.0). Adjust the center point or add more points as necessary.

You could also try rendering your smoke as a density pass B-G-R (in the KeyMode swatch), so red is the most dense, green the midrange, and blue the least dense, or I suppose you could do whatever order or colors you want and what would work best for you. Then adjust in comp.
poof ~>Vimeo<~
  09 September 2012
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
Thread Closed share thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Society of Digital Artists

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump

All times are GMT. The time now is 11:56 PM.

Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.