Cool Stuff

Some interesting stuff I’ve worked on over the years. By no means exhaustive, just a sample of the diversity of work I’ve done.

CUDA-based Blake3 GPU Miner

When Decred changed its Proof-of-Work algorithm to Blake3, it ended up not having enough CPU miners to advance the chain. Senior Developer Dave Collins quickly wrote a Blake3 GPU kernel for OpenCL, while I helped porting it (and the surrounding relevant code) to CUDA.

First CUDA-related PR.

Decred Multi-owner Ticket Buying

Decred has a Proof of Stake component that works through an on-chain ticket voting process. Individual users may “purchase” tickets (i.e. lock their DCR in a special transaction), which has a certain “cost”.

Before being a full time contractor, I devised and implemented a way of allowing multiple people to safely share purchase of a ticket on-chain. This involves several abstraction layers of the entire blockchain stack.

After running it for a couple of years, I also started trying to solve this problem in a more elegant way on the blockchain’s Layer 2.

Plasma Torch Height Control

Some plasma cutter power modules offer sensors that allow improved cutting performance by controlling the height of the plasma torch in relation to the work material.

While working on the CNC division at Gigatron, I developed a software to use such sensors to allow cutting variable-height pieces.

See the full video

Tangential Leather Cutting

Cutting leather, glass, foam and several other types of stock material require an active “tangential” cutting tool: the cutting tool must track the direction of the movement.

At Gigatron I developed both CAD and CAM modules to generate G-Code for such types of machines that we built.

See the full video.

CAD/CAM Suite

One of my first projects at Gigatron. I designed and wrote a CAD/CAM suite that ended up used in mulitple types of CNC machines. In the image, the shoe CAD software.

Nesting Problem

The “nesting” (2D irregular packing) problem involves optimizing cutting shapes from a stock material.

The above image shows the No Fit Polygon (NFP) calculation. One of the steps needed to determine a good nesting solution.

GLScene

Back in between 2002 and 2006 I was very involved in game programming and Delphi. I used to contribute to GLScene (the leading 3d graphics engine for Delphi way back when). This is a screenshot for the redesign I made for the main page.

GLScene was also one of the first Free Software projects in which I have credited contributions that can still be found online. The linked commit shows a plugin that creates an “explosion” special effect. This commit is from March 2002!

Isometric Engine

Isometric engine I wrote in Delphi+Directx way back in 2001/2002.

Intranet SysAdmin and Software

Back in 2006-2008, while working as a teacher, I ended up helping with sysadmin duties at the school. One of the things I did was to write a whole software stack for the school’s intranet, including an IPFW plugin, to allow teachers to monitor and block internet usage at each computer lab.

The picture shows an old AMD K6-II that we repurposed as our FreeBSD server. This single machine ended up serving as proxy and cache for a network of over 140 computers in the school.

Other

I have also worked on numerous interesting projects that I cannot publicly talk about. But if you’d like to know more, drop me a line .

Comments