Implementing 3D Graphics Basics

February 11, 2026 by Bryan Cockfield 16 Comments

Plenty of our childhoods had at least one math teacher who made the (ultimately erroneous) claim that we needed to learn to do math because we wouldn’t always have a calculator in our pockets. While the reasoning isn’t particularly sound anymore, knowing how to do math from first principles is still a good idea in general. Similarly, most of us have hugely powerful graphics cards with computing power that PC users decades ago could only dream of, but [NCOT Technology] still decided to take up this project where he does the math that shows the fundamentals of how 3D computer graphics are generated.

The best place to start is at the beginning, so the video demonstrates a simple cube wireframe drawn by connecting eight points together with lines. This is simple enough, but modern 3D graphics are really triangles stitched together to make essentially every shape we see on the screen. For [NCOT Technology]’s software, he’s using the Utah Teapot, essentially the “hello world” of 3D graphics programming. The first step is drawing all of the triangles to make the teapot wireframe. Then the triangles are made opaque, which is a step in the right direction but isn’t quite complete. The next steps to make it look more like a teapot are to hide the back faces of the triangles, figure out which of them face the viewer at any given moment, and then make sure that all of these triangles are drawn in the correct orientation.

Rendering a teapot is one thing, but to get to something more modern-looking like a first-person shooter, he also demonstrates all the matrix math that allows the player to move around an object. Technically, the object moves around the viewer, but the end effect is one that eventually makes it so we can play our favorite games, from DOOM to DOOM Eternal. He notes that his code isn’t perfect, but he did it from the ground up and didn’t use anything to build it other than his computer and his own brain, and now understands 3D graphics on a much deeper level than simply using an engine or API would generally allow for. The 3D world can also be explored through the magic of Excel.

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A Quick Primer On TinkerCAD’s New Features

November 18, 2025 by Lewin Day 9 Comments

TinkerCAD had its first release all the way back in 2011 and it has come a long way since then. The latest release has introduced a raft of new, interesting features, and [HL ModTech] has been nice enough to sum them up in a recent video.

He starts out by explaining some of the basics before quickly jumping into the new gear. There are two headline features: intersect groups and smooth curves. Where the old union group tool simply merged two pieces of geometry, intersect group allows you to create a shape only featuring the geometry where two individual blocks intersect. It’s a neat addition that allows the creation of complex geometry more quickly. [HL ModTech] demonstrates it with a sphere and a pyramid and his enthusiasm is contagious.

As for smooth curves, it’s an addition to the existing straight line and Bézier curve sketch tools. If you’ve ever struggled making decent curves with Bézier techniques, you might appreciate the ease of working with the smooth curve tool, which avoids any nasty jagged points as a matter of course.

While it’s been gaining new features at an impressive rate, ultimately TinkerCAD is still a pretty basic tool — it’s not the sort of thing you’d expect to see in the aerospace world or anything. ut it’s a great way to start whipping up custom stuff on your 3D printer.

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Learn What A Gaussian Splat Is, Then Make One

October 31, 2025 by Donald Papp 16 Comments

Gaussian Splats is a term you have likely come across, probably in relation to 3D scenery. But what are they, exactly? This blog post explains precisely that in no time at all, complete with great interactive examples and highlights of their strengths and relative weaknesses.

Gaussian splats excel at making colorful, organic subject matter look great.

Gaussian splats are a lot like point clouds, except the points are each differently-shaped “splats” of color, arranged in such a way that the resulting 3D scene looks fantastic — photorealistic, even — from any angle.

All of the real work is in the initial setup of the splats into the scene. Once that work is done, viewing is the easy part. Not only are the resulting file sizes of the scenes small, but rendering is computationally simple.

There are a few pros and cons to gaussian splats compared to 3D meshes, but in general they look stunning for any kind of colorful, organic scene. So how does one go about making or using them?

That’s where the second half of the post comes in handy. It turns out that making your own gaussian splats is simply a matter of combining high-quality photos with the right software. In that sense, it has a lot in common with photogrammetry.

Even early on, gaussian splats were notable for their high realism. And since this space has more than its share of lateral-thinkers, the novel concept of splats being neither pixels nor voxels has led some enterprising folks to try to apply the concept to 3D printing.

A man is looking at a volumetric display while using one finger to interact with it. Two roughly-spherical blue shapes are visible in the display, and he is moving his index finger toward one of them.

Elastic Bands Enable Touchable Volumetric Display

April 14, 2025 by Aaron Beckendorf 12 Comments

Amazing as volumetric displays are, they have one major drawback: interacting with them is complicated. A 3D mouse is nice, but unless you’ve done a lot of CAD work, it’s a bit unintuitive. Researchers from the Public University of Navarra, however, have developed a touchable volumetric display, bringing touchscreen-like interactions to the third dimension (preprint paper).

At the core, this is a swept-volume volumetric display: a light-diffusing screen oscillates along one axis, while from below a projector displays cross-sections of the scene in synchrony with the position of the screen. These researchers replaced the normal screen with six strips of elastic material. The finger of someone touching the display deforms one or more of the strips, allowing the touch to be detected, while also not damaging the display.

The actual hardware is surprisingly hacker-friendly: for the screen material, the researchers settled on elastic bands intended for clothing, and two modified subwoofers drove the screen’s oscillation. Indeed, some aspects of the design actually cite this Hackaday article. While the citation misattributes the design, we’re glad to see a hacker inspiring professional research.) The most exotic component is a very high-speed projector (on the order of 3,000 fps), but the previously-cited project deals with this by hacking a DLP projector, as does another project (also cited in this paper as source 24) which we’ve covered.

While interacting with the display does introduce some optical distortions, we think the video below speaks for itself. If you’re interested in other volumetric displays, check out this project, which displays images with a levitating styrofoam bead.

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DIY 3D Hand Controller Using A Webcam And Scripting

October 25, 2024 by Heidi Ulrich 3 Comments

Are you ready to elevate your interactive possibilities without breaking the bank? If so, explore [Caio Bassetti]’s tutorial on creating a full 3D hand controller using only a webcam, MediaPipe Hands, and Three.js. This hack lets you transform a 2D screen into a fully interactive 3D scene—all with your hand movements. If you’re passionate about low-cost, accessible tech, try this yourself – not much else is needed but a webcam and a browser!

The magic of the project lies in using MediaPipe Hands to track key points on your hand, such as the middle finger and wrist, to calculate depth and positioning. Using clever Three.js tricks, the elements can be controlled on a 3D axis. This setup creates a responsive virtual controller, interpreting hand gestures for intuitive movement in the 3D space. The hack also implements a closed-fist gesture to grab and drag objects and detects collisions to add interactivity. It’s a simple, practical build and it performs reliably in most browsers.

For more on this innovation or other exciting DIY hand-tracking projects, browse our archive on gesture control projects, or check out the full article on Codrops. With tools such as MediaPipe and Three.js, turning ideas into reality gets more accessible than ever.

DOOM On A Volumetric Display

September 9, 2024 by Dave Rowntree 15 Comments

There’s something magical about volumetric displays. They really need to be perceived in person, and no amount of static or video photography will ever do them justice. [AncientJames] has built a few, and we’re reporting on his progress, mostly because he got it to run a playable port of DOOM.

Base view of an earlier version showing the motor drive and PSU

As we’ve seen before, DOOM is very much a 3D game viewed on a 2D display using all manner of clever tricks and optimizations. The background visual gives a 3D effect, but the game’s sprites are definitely very solidly in 2D land. As we’ll see, that wasn’t good enough for [James].

The basic concept relies on a pair of 128 x 64 LED display matrix modules sitting atop a rotating platform. The 3D printed platform holds the displays vertically, with the LEDs lined up with the diameter, meaning the electronics hang off the back, creating some imbalance.

Lead, in the form of the type used for traditional window leading, was used as a counterbalance. A Raspberry Pi 4 with a modified version of this LED driver HAT is rotating with the displays. The Pi and both displays are fed power from individual Mini560 buck modules, taking their input from a 12 V 100 W Mean-Well power supply via a car alternator slip ring setup. (Part numbers ABH6004S and ASL9009 for those interested.) Finally, to synchronise the setup, a simple IR photo interrupter signals the Pi via an interrupt.

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Hackaday Links: June 23, 2024

June 23, 2024 by Dan Maloney 9 Comments

When a ransomware attack targets something like a hospital, it quickly becomes a high-profile event that understandably results in public outrage. Hospitals are supposed to be backstops for society, a place to go when it all goes wrong, and paralyzing their operations for monetary gain by taking over their information systems is just beyond the pale. Tactically, though, it makes sense; their unique position in society seems to make it more likely that they’ll pay up.

Which is why the ongoing cyberattack against car dealerships is a little perplexing — can you think of a less sympathetic victim apart from perhaps the Internal Revenue Service? Then again, we’re not in the ransomware business, so maybe this attack makes good financial sense. And really, judging by the business model of the primary target of these attacks, a company called CDK Global, it was probably a smart move. We had no idea that there was such a thing as a “Dealer Management System” that takes care of everything from financing to service, and that shutting down one company’s system could cripple an entire industry, but there it is.

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