I'm a beginner and wan't to know more about the fluid domain objects. Is it possible to make our fluid domain object from a cylinder? A lot of tutorials on YouTube use a cube for it. I have also tried to make my domain object from a cylinder but it's not affecting anything and I just want to make sure I did it right. Is cube really the base of a domain?
While i can't be certain that those tutorials show something else like using an object to limit the fluid to the form of an cylinder, which is not impossible, i can say that the old as well as the new Mantaflow fluid system always uses a cube or to be more precise the bounding box (which is a cube-shape covering the entire geometry of the domain object) to simulate.
So the answer to your question is yes and no:
- Yes you can use a cylinder object and make it a domain (all types of geometry can be used actually, as long as it is a mesh)
- No the cylinder object will not be used as a cylinder, but only it's bounding box will be used. (which is the answer to the second question in your question as well)
Yes, you can use Cylinder object as domain, but shape is not used in calculation, only dimension of the object (see Xylvier's answer).
So just an extension ... if you need liquid inside cylindrical shape
- use Cylinder object as Effector (Physics Properties > Liquid).
Common problem is blocky colision (outer) shape.
You can solve it by using Boolean modifier > Intersect > Object - the same cylinder object.