1) Working with high-resolution grids can be a killer on your resources. So itÆs usually best to work at low resolutions with your fluid container, then adjust them when it comes to your final simulation. And donÆt forget to cache them!
A neat thing to know is that the only difference between the 2D and 3D containers is a simple flag under the hood called æis2dÆ. This means that you can create a 3D container then, in the Expression Editor, create an expression for the container like æis2d = trueÆ, after which the container will be 2D. You can then work at high speeds, only to turn the flag to æfalseÆ when you want to switch it back to 3d!
2) One useful thing to note is that you donÆt always need to use fluids for your effects. You can in fact create a simple fluid and assign it to a particle system that uses a cloud s/w shader and youÆre able to use that fluid as if it were instanced in a way. With a few expressions and variations to the look of it it can work quite well. This allows you to avoid having to run long fluid simulations and just use it as a shader with your controlled particles.
3) Keep in mind at all times that the job is never done once you hit render. ItÆs always best to break it your piece up into layers, and render these out in passes (city, nuke, nuke dirt, clouds, fog, etc.) Bring these into your favorite compositing package to manipulate the images further. Here youÆll have a lot more control over the look of the image: for example, by colour correcting your work, adding glow, heat distortions or other effects to it, or integrating it into live action. Taking the extra time to refine your work in this way can add a lot to the quality of the final image.
