View Full Version : Smoke Problem

07-01-2004, 07:59 AM
I made smoke for an exaust on my friends truck. The problem is when I export the smoke effect it has a black background, so using a matte in Premere doesnt help, it fades and the black usually gets trasparent. Well my main issue is the smoke in Maya, I create an emitter, emitter type is directional with a particle render type of mutlipoint. I have had the best luck with that. I have tried Cloud s/w, I cannot get that to work to save my life, it looks horrible, and nothing like smoke. Multipoint works pretty good, but it looks too much like spots and not enough like a big blob of smoke. I have used the particle size and that doesnt help. I cant get the color right either. If anyone can help me out with making smoke please tell me what im doing wrong.

My main problems are: Texture of the Smoke, looks too much like particles and not like smoke. I will try to post a screen shot of what it looks like.

Thanks in advance for the help

07-01-2004, 08:09 AM
It wont let me post an attachment yet, but when I can i'll put it up of what the smoke looks like.

07-01-2004, 01:36 PM
Have you tried multipass rendering. I assume you are using the hardware render buffer, right? turn multipass to about 9 and turn on antialiasing. should smooth the individual points together some. if that's still too chuncky, you could try blurring it in post. if you really aren't happy with the results you get from particles, you could also try fluids.

07-01-2004, 07:13 PM
Ya I tried multipass on 9, my blur was set to 4, should I go higher? It didnt seem too bad, but id like it to look more like cloud, maybe have to use more blur not sure.

07-01-2004, 07:14 PM
I uploaded an image of it, the smoke is real faint because of the track matte I have to use in Premiere to get it to work.

07-01-2004, 07:59 PM
I also tried Cloud s/w which gives me the effect I want, the problem is, that its blue. So I put a Ramp on it, and make it go from black to grey, but the picture turns out all weird. I dont want the smoke to be just one color, id like it to be black and grey.

07-01-2004, 11:36 PM
Are you rendering with an Alpha?

07-02-2004, 03:41 AM
When I go to render, it says Alpha (mask) but the background is always black.

07-02-2004, 03:46 AM
Looking at your sample render, I think you put the ramp on wrong slot.

The gradient of the ramp should involve what so called age in per particle basis. When each particle was born, you may want it to be black, but after a certain time you want the particle to be greyed out or even white due to diffusion with air.

You will need to hook up the age normalized attribute of a particleSamplerInfo node to the v-coord of your ramp and feed the outColor of the ramp to life Color of each particle.

Of course if you want to add more realistic result you should also use another ramp to control transparency of each particle and another ramp probably to control the radius.

I just do a quick setup for you, and this is the render test. I'm not sure Maya 5.0 has control for self shadowing of the particle cloud, maybe I should check that one too.

07-02-2004, 06:44 AM
Ya what you have is exactly what I want. Is there a way you can message me or something and explain to me better how you did that?

07-02-2004, 06:48 AM
Ok, I have the cloud s/w one, and I have it looking like yours, but now im working on the color. Do I add the ramp to: LifespanPP?

Can you explain this to me, I dont understand how to do this:

You will need to hook up the age normalized attribute of a particleSamplerInfo node to the v-coord of your ramp and feed the outColor of the ramp to life Color of each particle.

07-02-2004, 06:57 AM
No, it is a standard cloud(SW) particles.

Are you familiar with per particle attributes?.

Do you Yahoo??????. You could IM me on Yahoo if you want, I got 2 hours break for my class. I can help you setting it up if you do Yahoo.....

07-02-2004, 06:59 AM
I have AIM, but I guess I could load Yahoo

07-02-2004, 07:01 AM
You can contact as misterdi_99 on Yahoo.

07-02-2004, 09:50 PM
Thanks Misterdi for helping me with the smoke, it looks great. For anyone else who wants to know how to do it, Iíll post how Misterdi showed me to do it.

Make Smoke:

First Create a standard directional emitter, let say put direction in +Y, use very low rate let say 10 (you can change this to whatever you want)
Go through and adjust the shape the way you want, you can make the smoke a constant or random, whatever you want.
Change the Particle Render type to: Cloud S/W
Open Hypershade and add particleCloud1, Particle Sampler, and Ramp to your work area. You can use your MMB (middle mouse button) to drag them to work area.
Now MMB on the particle sampler, and drag n drop it on top of the ramp, choose other when Maya asks. It will open another windows called connection editor. (On the left side is incoming signal, and on the right side is destination)
From the left side (particleSamplerInfo), look for attribute called Age Normalized. Select it and from the right side, find Uv Coord, expand the compound attribute by clicking on + sign and select the V Coord.
Close that and go back to Hypershade
Now MMB on the ramp, drag n drop it into particleCloud. Choose color when Maya asks.
Go back to your ramp; adjust the color the way you want. (Dark color on bottom, light color on top, so the smoke will go from dark to light)
Adding Diffusion to Smoke
To add diffusion go back to Hypershade and add another ramp, you can name it transparency ramp if you like.
Using the same particleSamplerInfo, drag n drop it to the transparency ramp and repeat the sequence we have done before, choose other, and connect age normalized to v coord.
Then edit your ramp so it is almost white at the top, and grey at the bottom. (Grey in this case is half transparent, white is fully transparent)
Now drag and drop the transparency ramp to particleCloud1 and connect to transparency.
Adjust Radius (radius of particles start small and get bigger as they move up)
Open attribute editor of the particleShape, and look at the per particle area.
There are 3 buttons underneath Add Dynamic Attributes, choose General.
It will open Add Attribute Editor, select Particle Tabs.
You will see a bunch of particle attributes there, find radiusPP, select it and press ok.
In your attribute editor now you will see in Per Particle Attribute area there is one more line called radiusPP, right click on it and do CreateRamp.
Now the box will be filled with <- arrayMapper1 etc.
Right click on that and do EditRamp.
Now this is our radiusPP, represent in ramp, by default it will be connected with normalized age already. So what we need to do is set the color at the bottom to a value to use as the birth radius.
Then you set the top color to a higher value. (I used 1 at the bottom and 3 at the top, but you can experiment and have any value you want)
Now you can Render in Software Render mode.

Hope this helped. If there is any problems let me know, and Iíll change it. Thanks again Misterdi.

07-19-2004, 03:03 PM
u mentioned about 'software rendering' this smoke - i'm using smoke also but used the 'create smoke' option - in Maya 5 -

when i software render it, it doesn't show the smoke. i read in the maya manual that u have to hardware render it. if that's the case, i can't output to 'avi' ... any possible solutions? b/c importing frame by frame into something like premiere would be hardcore.


07-20-2004, 10:15 AM
I believe 'create smoke' is using sprite particle type. It has several expressions to control the particles. But since it is a sprite particle, you need to render it using hardware renderer.

BTW: I don't think there is a problem importing image sequences to Premier, just make sure you imported as an image sequence, using padding for file number make it easier for Premier to understand the sequence. There should be a check box to import images as an image sequence in the import file dialog in Premier.

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