Viewing profile — markstock

The nice thing is that every gpu is like a little distributed-memory machine, and programming it for optimal memory locality (registers, shared, global) and bandwidth is an essenti…

The author is spot on. As an HPC performance engineer and computational artist, I could tell numerous stories about it, but I'll summarize three: The common method for evaluating M…

Please don't call this "full N-body dynamics" if only the outer planets are involved in the integration.

My go-to rule that's held since 2008 has been that a GPU can do about 10x the math that a similarly-priced CPU running properly optimized code can. My 5070Ti can realize about 20 T…

There have been polls. The AI hate thing is almost exclusively a USA thing.

Generative artist here: the beautiful thing about this exploration is that these techniques can be applied to ANY vector field, whether they originate in random noise or global sim…

Yes, I do 4th order interpolation (M4') on the GPU. This paper is for 3rd order, though, but the methods may extend. I suppose because the fetches are generally to similar memory r…

I should add that this is a major "tell" for detecting when an app uses the Stable Fluids method: obvious mass loss (and very viscous, energy-dissipating flow).

People who run WSL are not normal users. The filesystem problems make Windows+WSL feel like a Trabant when you're used to a Porsche.

Because Windows is the operating system of Not Getting Fired. Fear is a stronger motivator than creativity or productivity.

On the other side, I am a lifelong Linux user, and even with advanced LLMs, trying to get Microsoft Windows to behave sanely takes hours every month for years on end (thanks, day j…

Before you go adding vorticity confinement, consider performing a higher-order backward advection scheme (Runge-Kutta 2nd or similar), and using a higher-order interpolation method…

You are correct: Stable Fluids extends to 3d relatively easily.

One of the nice aspects of Stable Fluids is that you don't need to iterate the pressure correction terms to convergence. Just run a fixed number of Jacobi or Gauss-Seidel sweeps an…

Then you want Foundations of Multidimensional and Metric Data Structures by Samet. Unless you already have it, then enjoy some pretty (organic) trees.

Sure, I usually measure performance of methods like these in terms of FLOP/s; getting 50-65% of theoretical peak FLOP/s for any given CPU or GPU hardware is close to ideal.

Quadtrees and octrees are themselves quite deep research areas. If the acceleration data structures interest you, I highly recommend Hanan Samet's book "Foundations of Multidimensi…

Note that even without an acceleration structure ("direct summation" in N-body research terminology), a CUDA program or GLSL shader program can exceed 60 fps with 10,000 to 20,000 …

The general algorithm used here (of computing attraction and repulsion forces between pairs of particles) is very similar to that used in simulations of many interesting phenomena …

Thank you - I was just about to point out some of that. The reason that the flocks are tight is because the separation "force" is normally computed as a repulsion between a target …

Just a few volumes from my bookshelf related to this: Network Analysis in Geography, Haggett and Chorley Cities and Complexity, Batty Urban Grids, Busquets et al

Let's be a little more clear: these are not "laws" as much as they are scaling relationships, this is not "new math" (see Ziph and others), and central planning has always had an i…

Something doesn't add up here. The listed peak fp64 performance assumes one fp64 operation per clock per thread , yet there's very little description of how each PE performs 8 flop…

Exactly this. Whenever I talk about how I got started in computer art over 40 years ago, I always mention the fact that a screen back then was a one-way device: TV network to you. …

Yes, this appears to use Stam's Stable Fluids algorithm. Look for the phrases "semi-Lagrangian advection" and "pressure correction" to see the important functions. The 3d version s…