Gnomon DVD: Maya Fluid Effects: Fundamentals
Fluid is the modern version of particles in Maya. It is like some preset flowing particles that are ready to be manipulated for our needs, and proves to be powerful and effective for shots requiring smoke, dust, explosion, clouds etc. In this DVD David Schoneveld (He’s kinda boring though) guides us along the fundamentals of Maya Fluids.
The difference between fluids and particles is that fluids should be visualized as a space which already contain fluids, and the emitter sort of emits dyes, while particles start from nothing in space.
One thing to note is that fluids can use fields to control them, but it is recommended that we only turn it on for no less than 3 frames, or it might go crazy.
Most part of the DVD talks about each attribute of the fluid effect. These should be easily available in Maya docs. We should turn calculation on only when needed because fluid effects slows down the scene. Fluids are very much tweaked by density, velocity, temperature, fuel and color, which is totally different from how particles work.
Often people will set color based on density and incandescence based on temperature. Opacity is almost always set to density. Add a bit of damp, like 0.005 as your default.
Using preview quality in render settings (software) is enough for fluids, because we would take forever to render at production quality. We should adjust the shading quality in the attributes instead to get better quality renders.
To get the look we want, mostly it’s about looking at the viewport more than getting right values for the attributes, because nothing is right. We would be spending lots of time tweaking the textures in attribute editor. Actually, for production we probably would be starting from the presets made in maya fluid examples as it usually gets us near to what we want.
For instance, clouds are made primarily by opacity textures. We could animate the texture time to have the clouds moving. This is an example of non-dynamic simulation which speeds up production time tremendously when only textures are animated.
For fluid emitters, usually our settings for density and hear per voxel are not more than 20. A puff of smoke is 20, 20, and fuel is likely not used most of the time.
The extend fluid under fluid effects menu is a nice simple way to increase the area of fluid calculation, especially when we are tracking it for a shot. Make motion field is another useful tool when we need to have fluids colliding with a moving object, which can be tuned by attenuation.
For caching, we can create a new cache to preview the simulation easily on the time slider. To delete a cache from the current frame onwards, use truncate cache, which we would then use append cache to join up a good simulation.
The final example shows how to make a cloud bank within a sky fog using 2 fluid containers. Seems like extremely simple to get extremely good renders!