rendering

9 Articles

Quake In 276 KB Of RAM

October 5, 2024 by 20 Comments

Porting the original DOOM to various pieces of esoteric hardware is a rite of passage in some software circles. But in the modern world, we can get better performance than the 386 processor required to run the 1993 shooter for the cost of a dinner at a nice restaurant — with plenty of other embedded systems blowing these original minimum system requirements out of the water.

For a much tougher challenge, a group from Silicon Labs decided to port DOOM‘s successor, Quake, to the Arduino Nano Matter Board platform instead even though this platform has some pretty significant limitations for a game as advanced as Quake.

To begin work on the memory problem, the group began with a port of Quake originally designed for Windows, allowing them to use a modern Windows machine to whittle down the memory usage before moving over to hardware. They do have a flash memory module available as well, but there’s a speed penalty with this type of memory. To improve speed they did what any true gamer would do with their system: overclock the processor. This got them to around 10 frames per second, which is playable, but not particularly enjoyable. The further optimizations to improve the FPS required a much deeper dive which included generating lookup tables instead of relying on computation, optimizing some of the original C programming, coding some functions in assembly, and only refreshing certain sections of the screen when needed.

On a technical level, Quake was a dramatic improvement over DOOM, allowing for things like real-time 3D rendering, polygonal models instead of sprites, and much more intricate level design. As a result, ports of this game tend to rely on much more powerful processors than DOOM ports and this team shows real mastery of their hardware to pull off a build with a system with these limitations. Other Quake ports we’ve seen like this one running on an iPod Classic require a similar level of knowledge of the code and the ability to use assembly language to make optimizations.

Thanks to [Nicola] for the tip!

Llama.ttf Is AI, In A Font

June 26, 2024 by 6 Comments

It’s a great joke, and like all great jokes it makes you think. [Søren Fuglede Jørgensen] managed to cram a 15 M parameter large language model into a completely valid TrueType font: llama.ttf. Being an LLM-in-a-font means that it’ll do its magic across applications – in your photo editor as well as in your text editor.

What magic, we hear you ask? Say you have some text, written in some non-AI-enabled font. Highlight that, and swap over to llama.ttf. The first thing it does is to change all “o” characters to “ø”s, just like [Søren]’s parents did with his name. But the real magic comes when you type a length of exclamation points. In any normal font, they’re just exclamation points, but llama.ttf replaces them with the output of the TinyStories LLM, run locally in the font. Switching back to another font reveals them to be exclamation points after all. Bønkers!

This is all made possible by the HarfBuzz font extensions library. In the name of making custom ligatures and other text shaping possible, HarfBuzz allows fonts to contain Web Assembly code and runs it in a virtual machine at rendering time. This gives font designers the flexibility to render various Unicode combinations as unique glyphs, which is useful for languages like Persian. But it can just as well turn all “o”s into “ø”s or run all exclamation points through an LLM.

Something screams mischief about running arbitrary WASM while you type, but we remind you that since PostScript, font rendering engines have been able to run code in order to help with the formatting problem. This ability was inherited by PDF, and has kept malicious PDFs in the top-10 infiltration vectors for the last fifteen years. [Citation needed.] So if you can model a CPU in PDF, why not an LLM in TTF? Or a Pokemon clone in an OpenType font?

We don’t think [Søren] was making a security point here, we think he was just having fun. You can see how much fun in his video demo embedded below.

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At Last! Faster OpenSCAD Rendering Is On The Horizon

October 3, 2023 by 30 Comments

Known as “The Programmers Solid 3D CAD Modeller”, OpenSCAD is used by many people for whom writing code comes more naturally than learning a fiddly user interface. It’s a very capable piece of software, but regular users will tell you that it can be rather slow when it comes to rendering your work. We’re very pleased to see that a fix for this has been produced courtesy of [@ochafik], can now be found as an experimental feature in nightly builds, and will in due course no doubt find its way to official releases.

Despite a modern computer invariably having a multi-core architecture, it might surprise you to find that OpenSCAD wasn’t able to take advantage of this previously. The above-linked thread spans over a decade of experimenting and contains some fascinating discussions if you’re prepared to wade through it, and culminates a few weeks ago in the announcement of the new feature giving access to multiple CPUs. We don’t have it yet, but it’s great to know it’s in the works and we’re looking forward to render time involving considerably less of a wait.

So many OpenSCAD projects have passed through these pages over the years, it’s safe to say that it has a significant user base among Hackaday readers. It’s still something an AI hasn’t mastered yet though.

Thanks [pca006132] for the tip.

Adding Portals To Quake

July 6, 2023 by 14 Comments

For those who have played Quake extensively, adding portals seems unnecessary, as teleporters are already a core part of the game mechanics. What [Matthew Earl] accomplishes is more of the Portal style of portal by rendering what is on the other side of the portal with a seamless teleportation transition.

Of course, Quake is an old game with a software renderer. Just throwing another camera into the scene, rendering to another texture, and then mapping that texture to the scene isn’t an option. Quake uses an edge rasterizer and generates spans along scanlines that track where edges intersect the current scanline. Rather than making expensive per-pixel comparisons, [Matt] stashes the portal spans and renders them in a second render, so even with multiple portals, only a single screen’s worth of pixels are rendered.

However, this technique has no near clipping plane, which means objects can appear in the portal that don’t make any sense as they are in front of the portal’s viewpoint. Luckily, Quake has an ingenious method for polygon occlusion: the BSP. While [Matt] is manually checking polygons, the BSP is the perfect tool for bisecting a room along a plane. It’s an incredible hack, and we’re excited to see Quake expand into a puzzle game. [Matt] dives into greater detail on how the software renderer works in another video that’s well worth a watch.

Perhaps the most incredible aspect of this technique is that it could run on original hardware. If you want to bring a little more Quake to life, why not get the Quake light flicker in your house? Video after the break.

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Signed Distance Functions: Modeling In Math

April 12, 2023 by 13 Comments

What if instead of defining a mesh as a series of vertices and edges in a 3D space, you could describe it as a single function? The easiest function would return the signed distance to the closest point (negative meaning you were inside the object). That’s precisely what a signed distance function (SDF) is. A signed distance field (also SDF) is just a voxel grid where the SDF is sampled at each point on the grid. First, we’ll discuss SDFs in 2D and then jump to 3D.

SDFs in 2D

A signed distance function in 2D is more straightforward to reason about so we’ll cover it first. Additionally, it is helpful for font rendering in specific scenarios. [Vassilis] of [Render Diagrams] has a beautiful demo on two-dimensional SDFs that covers the basics. The naive technique for rendering is to create a grid and calculate the distance at each point in the grid. If the distance is greater than the size of the grid cell, the pixel is not colored in. Negative values mean the pixel is colored in as the center of the pixel is inside the shape. By increasing the size of the grid, you can get better approximations of the actual shape of the SDF. So, why use this over a more traditional vector approach? The advantage is that the shape is represented by a single formula calculated at many points. Most modern computers are extraordinarily good at calculating the same thing thousands of times with slightly different parameters, often using the GPU. GLyphy is an SDF-based text renderer that uses OpenGL ES2 as a shader, as discussed at Linux conf in 2014. Freetype even merged an SDF renderer written by [Anuj Verma] back in 2020. Continue reading “Signed Distance Functions: Modeling In Math” →

Several frames from Bad Apple

PineTime Smartwatch And Good Code Play Bad Apple

October 16, 2021 by 11 Comments

PineTime is the open smartwatch from our friends at Pine64. [TT-392] wanted to prove the hardware can play a full-motion music video, and they are correct, to a point. When you watch the video below, you should notice the monochromatic animation maintaining a healthy framerate, and there lies all the hard work. Without any modifications, video would top out at approximately eight frames per second.

To convert an MP4, you need to break it down into images, which will strip out the sound. Next, you load them into the Linux-only video processor, which looks for clusters of pixels that need changing and ignores the static ones. Relevant pixel selection takes some of the load off the data running to the display and boosts the fps since you don’t waste time reminding it that a block of black pixels should stay the way they are. Lastly, the process will compress everything to fit it into the watch’s onboard memory. Even though it is a few minutes of black and white pictures, compiling can take a couple of hours.

You will need access to the watch’s innards, so hopefully, you have the developer kit or don’t mind cracking the seal. Who are we kidding, you aren’t here for intact warranties. The video resides in the flash chip and you have to transfer blocks one at a time. Bad Apple needs fourteen, so you may want to practice on a shorter video. Lastly, the core memory needs some updating to play correctly. Now you can sit back and…watch.

Pine64 had a rough start with the single-board computers, but they’re earning our trust with things like soldering irons and Google-less Linux mobile phones.

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Drones, Clever Hacks, And CG Come Together For Star Wars Fan Film

August 11, 2016 by 12 Comments

We weren’t certain if this Star Wars fan film was out kind of thing until we saw the making of video afterwards. They wanted to film a traditional scene in a new way. The idea was to take some really good quadcopter pilots, give them some custom quadcopters, have them re-enact a battle in a scenic location, and then use some movie magic to bring it all together.

The quadcopters themselves are some of those high performance racing quadcopters with 4K video cameras attached. The kind of thing that has the power to weight ratio of a rocket ship. Despite what the video implies, they are unfortunately not TIE Fighter shaped. After a day of flying and a few long hikes to retrieve the expensive devices after inevitable crashes (which, fortunately, provided some nice footage), the next step was compositing.

However, how to trick the viewer into believing they were in a X-Wing quadcopter? A cheap way to do it would be to spend endless hours motion tracking and rendering a cockpit in place. It won’t look quite real. The solution they came up with is kind of dumb and kind-of brilliant. Mount a 3D printed cockpit on a 2×4 with a GoPro. Play the flight footage on a smartphone while holding the contraption. Try to move the cockpit in the same direction as the flight. We’re not certain if it was a requirement to also make whooshing and pew pew laser noises while doing so, but it couldn’t hurt.

In the end it all came together to make a goofy, yet convincingly good fan film. Nice work! Videos after the break.

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