Blender Tutorial: Realistic large-scale water simulation
A visual guide to (near) perfect Blender water.
Intro
Blender fluid-simulation engine is tricky, and it usually takes a lot of experimentation to get something look 'right'. Unfortunately because of the complexity of the program, simulating a 10 second animation could take a day or two to calculate. Here I will attempt to save you some time and explain how to achieve a good looking large-scale water scene with minimum effort.
Basic workflow
Setup
Setting up the scene anyway you like, remember to have a DOMAIN BOX, an INFLOW or FLUID, and as many OBSTACLES as you like. This image shows what I have done. Right now, most of the fluid setting is still at default. I only changed the inflow rate to a non-zero number (otherwise nothing interesting will happen!)
The simulation with most settings at default >>
Horrible, isn't it? It will soon change.
Important Settings
There are several important settings involved in creating a realistic fluid simulation.
You NEED to set the fluid end time value high, otherwise the fluid will always behave like thick syrup, no matter how you tweak the gravity or any other setting. I have found that the only way to get a natural looking water flow is if the value is between 5-10. Also, the world size needs to be increased to 10, indicating to Blender that the physical size of the fluid scene is 10 cubic meters.
Exact same setup, only with endtime=5 and worldsize=10:
Resolution controls the overall detail of the water. Higher resolution will require more calculation time, but looks better. Same scene as above, except with the resolution turned up to 250.
See? It is already getting better.
Domain geometry and tweaks
As the fluid is taking shape, now would be a good time to revisit all the other settings and tweak them a bit until everything looks right. In this case, I changed the SLIP Value to 0.5 (Part Slip), and doubled the inflow amount since I wanted more water in the scene.Finally, remember to resize the domain cube so that it just hugs the boundary of the fluid simulation, do not leave excessive empty space, that would lead to longer computing time and higher memory usage.
Finally, you could also enable particles, which adds even more detail to the scene at the cost of slower rendering time.