7 votes
Accepted

Hodge Decomposition in fluid simulations

Suppose I have a fluid which, like water, is incompressible; that is, its density is constant. I can find out how this fluid is flowing; let's say I inject dye at various points and follow how the dye ...
gilgamec's user avatar
  • 901
4 votes
Accepted

Finite difference wave equation shown in paper is wrong?

Yes, it looks like a sign error in the paper. It looks like it was introduced in equation (4) and then carried through the following ones. Probably the authors wrote the source code first and the ...
Nathan Reed's user avatar
3 votes
Accepted

Rendering a particle system as a smooth blob

For culling faraway particles: as lightxbulb said, the keyword to search for is "acceleration structure". There are a variety of options: BVH, octree, kd-tree, uniform grid, or some ...
Nathan Reed's user avatar
3 votes
Accepted

Rigorous and simple explanation for satisfying boundary conditions in Stam and Bridson papers

First of all, I would like to state that handling the boundary conditions correctly is challenging, both from mathematical perspective and from an implementation perspective. Additionally, I think ...
dweber's user avatar
  • 126
3 votes
Accepted

Jos Stam's "Stable Fluids" boundary conditions

It's Dirichlet boundary condition. The quantities at domain boundaries will take either the same value as its inner neighbor or the negated value, depending on the condition $\mathbf{b}$. Take ...
Fei Zhu's user avatar
  • 146
3 votes

2D metaballs with marching squares and linear interpolation

as promised, here my answer to your question. As I can't follow your code completely (I spend most of my time implementing my code :D ) I can only explain to you what the last step is. So why do we ...
realvictorprm's user avatar
3 votes
Accepted

Rendering Fluid Simulations?

Here's a more complete answer from the extent of my knowledge. A sort of brief overview you can google more about. I'm sure I didn't cover all the different techniques but most branch off the ...
Andrew Wilson's user avatar
3 votes
Accepted

Fluid sim: CPU vs. GPU

Let's go through the paper you mentioned and try to list the factors which will affect your decision on whether to use GPU or CPU for simulation. I will also add some comments about my opinion for ...
TheBusyTypist's user avatar
2 votes

Conserving Mass in Liquid Simulation

From your code snippet and your result for 2x2 example, I can see that you are actually simulating a domain with only Neumann boundary conditions (slip wall). In this case, the system contains a null ...
TheBusyTypist's user avatar
1 vote
Accepted

Having trouble understanding advection from GPU gems fluid dynamics example

The cells with zero velocity are boundaries (walls) of the simulation domain. You will need to handle the boundary conditions explicitly. The advection itself cannot do much for you. From the context ...
TheBusyTypist's user avatar
1 vote

Particle & Fluid Simulation: Where to learn?

PBRT handles only the rendering part, not the simulation part. There are several books out on game physics that handle fluid simulation, the one on my bookshelf is David Eberly's "Game Physics".
Stefan Werner's user avatar

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