Maya Fluids Tutorial 1 - Clouds

Ok, by the end of this tutorial you should have a basic understanding of maya fluids and clouds you can use in any scene for future projects. Before i get into the nitty gritty of it all i'll explain the basic setup. It includes two maya fluids cube and a spotlight. One cube being the clouds and the other creating the blue haze/falloff effect of the sky.

This first part of the tutorial will show how to quickly create clouds with maya fluids.

First we need to create a 3D container from the Fluid Effects menu



When we open the first fluid rename it to clouds we intend on using this as our cloud layer. Firstly we want to change the properties of the cube. Change the size of the cube to 20,2,20 respectively. This increases the size of the cube. Now alter the resolution to 80,8,80. Increasing this will make the fluids more detailed when rendered.

You will notice several main attributes under the Contents Method tab. These are Density, Velocity, Temperature, Fuel and Colour Method. Make sure all of these are set to Off(zero) except for Colour Method which we want set to Use Shading Colour. The reason for this is because we don't want our clouds to move, we want them to just sit there....however you can play with settings to achieve a timelaps effect.



Ok now before we do anything else we want to go down to the Texture tab and turn tick Texture Colour and Texture Opacity. We do this now so we can see the changes we are about to make in the viewport. While we here change the Texture Type to Perlin Noise. Also at this point we want to turn on texturing in our viewport. To do this click on shading in the viewport you wish to view the clouds through. Change it from wireframe to smooth shade all.



SHADING
Next we want to open the Shading tab. Change the transparency RGB values all to 0.091. This will change the over all opacity of the clouds. Also change the Edge Dropoff to about 0.485 so the clouds fade off at the edge of the cube Now we move onto the Colour tab. Here we need to set up a gradual fade from white to black. For this we will need 3 points. The first point should already be set to white and should be set to a postion of 0.000. click anywhere on the gradient to create a 2nd point. The selected postion of the 2nd point should be around 0.743, it's selected colour should be 0.656 for all RGB values. Repeat this process for the 3rd point making the selected position a value of 1 and the RGB values all 1. Change the Colour Input to Y Gradient. This will help create the effect of light comming from above the clouds.



OPACITY
I won't go into too much detail here seeing you know all about selected positions/selected values etc. You need 5 points for the opacity. The following is a list of the points, their selected positions and their selected values.

point1
selected position = 1.000, selected value =.940
point2
selected position = 0.814, selected value =0.820
point3
selected position = 0.593, selected value =.0.600
point4
selected position = 0.479, selected value =0.360
point5
selected position = 0.429, selected value =0.000

Make sure the Opacity Input is set to constant and that Input Bias is set to 0.030. Open the Shading Quality tab and change Quality to a value of 3.000, this essentially is the sampling rate for the fluids.



TEXTURES
Finally we want to alter some of the texture settings for the Perlin Noise we set up in the beginning. Change the Amplitude to 0.976, Ratio to 0.408, the Frequency Ratio to 2.835 and the Frequency to 1.942. Also turn on Inflection



The end result should look something like this in the viewport.



And the render.



This scene needs alot more work i.e. Haze and lighting but this will hopefully give you guys a footing into maya fluids. Sorry for it seeming rushed, i'll update it in the near future to explain in more detail.

This last pic im just updating this tutorial with, it's an example of two results you can achieve with this technique.





Cheers!

~Todd.

That's a pretty intense tut, and some impressive results mate.

So does Maya let you view your volumetrics in real time inside the viewport? That must be bloody amazing.
If so is it like a thing where you can set viewport and rendering settings to be different?

Maya doesn't let you view volumetrics in real time really but it does let you view fluids in real time which is a differant type of volumetrics in a way. Fluids allows you to use graphical helpers like current arrows which displays the current of wind, density etc...through a dynamic animation. For example, hot air rises....if you set up a similar fluid effect with it being hot air you can actually see the flow of the fluids twist and twirl within the container. It's really amazing stuff!

You can also change settings for viewport rendering depending on your computer, a simple yet handy feature

Cheers,

~Todd.

yeah man, fix those images

the pictures still dont work

please don't beat me up Ty, my face is too pretty for...er um who am i kidding? Just fixed them! Thanks to Cam for hooking me up with some space.

Cheers,

~Todd.

Hey Todd! Thanks a lot! Your the man. Those clouds look amazing. I'm really looking forward to trying them out now!
Just the one query, do you know how could i project a light onto a cloud? You know like a 'Batman' signal? Will i be able to so this with fluids or does the clouds have to be a model?
Again, thanks Todd.
Iest

Hey Iest,

No problems man. Yeah it is possible to project a light onto a cloud. In that second picture i've actually got shadows and self shadowing turned on. I have a spotlight with volume light above the clouds simulating the sun. Fluids can easily interact with other objects in the world of Maya.

Keep me posted on how your clouds turn out mate!

Cheers,

~Todd.

Yaaay! He fixed it!!

Although I was rather hoping you'd just post the password online

Is there any way to take the results of this and turn it into a new sky environment texture?

Actually I should start a new thread for some other material/shader questions that I have.

AWESOME tutorial set btw. Much easier to get good results instead using the default sky environment on an image plane.

[EDIT] btw can anyone tell me how to render a set of six images to map onto a cube that fit seamlessly together?
Like say the camera was at the center and I just reoriented the aim six times to snap the images, but how can I be sure I am getting a 90 degree FOV with a square aspect ratio image? I've tried under special effects setting the (???) value from 1.44 to 1 but I still get seams in the render set. Also Maya tends to put a dark strip down the left side of my images on occasion.

hey i followed this tutorial, and i dont get nice looking clouds but like a whole rectangle of clouds, whats the key i have to chanhe is a Attribute editor to do this?

Hmm i dont know, that's pretty strange - when i did it, i had great results, make shure you change all the settings that Todd mentioned, and you should be able to get it. Im not at my machine right now so i cant confirm exactly what to do sorry mate.