In short, the two fields just look similar, but are actually extremely different fields.
Physical simulations need to preserve entropy, maximum principle, energy conservation and other kinds of conservation, preservation of consistent states, convergence in case of finer mesh.
There are multiple equations which model different forms of fluid:
1. Incompressible Euler (For liquid)
2. Compressible Euler (For non-viscous gases)
3. Navier Stokes Equations (For viscous liquids)
There are multiple solver methods:
1. Finite Difference
2. Finite Element
3. Discontiguous Galerkin Finite Element
4. Finite Volume Method
There are multiple equation methods:
1. equation splitting is just one of the many methods possible.
Just because the equation is unique does not mean that the solution is unique. Single equation provably have multiple and even infinite solution for the same initial condition. Computer graphics fluid simulation does not care (with a good reason) about this and hence, often their simulations even though they look kind of nice, are often incorrect since they do not demonstrate various physical characteristics that must be preserved.
In contrast, the qualitative/quantitative constraint in physical simulations are very strict. You need to know a lot of theoretical math to even understand if you are even computing the correct solution.
Physical simulations need to preserve entropy, maximum principle, energy conservation and other kinds of conservation, preservation of consistent states, convergence in case of finer mesh.
There are multiple equations which model different forms of fluid: 1. Incompressible Euler (For liquid) 2. Compressible Euler (For non-viscous gases) 3. Navier Stokes Equations (For viscous liquids)
There are multiple solver methods: 1. Finite Difference 2. Finite Element 3. Discontiguous Galerkin Finite Element 4. Finite Volume Method
There are multiple equation methods: 1. equation splitting is just one of the many methods possible.
Just because the equation is unique does not mean that the solution is unique. Single equation provably have multiple and even infinite solution for the same initial condition. Computer graphics fluid simulation does not care (with a good reason) about this and hence, often their simulations even though they look kind of nice, are often incorrect since they do not demonstrate various physical characteristics that must be preserved.
In contrast, the qualitative/quantitative constraint in physical simulations are very strict. You need to know a lot of theoretical math to even understand if you are even computing the correct solution.