Experimenting with a SDF material blend function that is "stamps" the material volumetrically. The previous function I was using (which is the common one) blends the material around the surface influence area, and so would have no effect below ground.

Almost finished implementing shadows. This ended up being a bigger project than expected, as I decided to render world-space shadow map cascades that update/"scroll" incrementally as the camera moves. The benefit of this is that very little work needs to be done every frame!

You mock, but this is actually art.

Prowling around the SDF yards after dark, desecrating spheres with reckless abandon.

Playing with RenderDoc's shader debugger, and the "Run forwards to NaN/Inf" feature is incredibly useful and got me to the problem in one click. [a story continued... ⬇️ :) ]

Nicely-explained and illustrated article on making a spherical Minecraft-style blocky world. (with playable web demo) www.bowerbyte.com/posts/blocky...

TIL the concept of a "net" of a polyhedron - the way its faces can be flattened and then "folded" back together. These are 11 nets of a cube! en.wikipedia.org/wiki/Net_(po...

While searching around for solutions to geometric problems, I periodically end up on this big list of PDFs written by Dave Eberly that cover a lot of topics rigorously. Recommended! www.geometrictools.com/Documentatio...

Great article by @aras-p.bsky.social comparing the perf of rasterizing single-pixel triangles vs. compute-shader splatting. The most fascinating part of this is how much different GPUs differ in comparative perf, and how they respond to different scenarios. aras-p.info/blog/2025/08...

I've noticed a huge difference in my ability to tune parameters and have an intuition about the tuning space when I add a control (e.g., slider) to drag continuously through the space. Being able to type in values is great too (either UI or hot-reloaded code), ...

A trick I forget about with shading languages is that you can left-multiply vectors with matrices to transform by the transpose. So if you have a rotation matrix "worldToLight", you can use both: worldToLight * worldPos -> lightPos lightPos * worldToLight -> worldPos 1/

Digging with spheres (🔵) vs octahedrons (🔷)

Read this recent paper on hierarchical pruning/culling of SDF operations, and it presents a really appealing approach that's simple to implement and pretty general. wbrbr.org/publications... However! I see that they don't address incremental updates to the structure ...

Just make it exist first. You can make it worse with each new pass while getting increasingly frustrated later.

This is what I came up with to calculate a tight AABB for an octahedron. The 6 vertices of the octahedron all lie on a single axis, so they each "pick" a single column of the rotation matrix. abs() handles the fact that the vertices are mirrored w.r.t. the origin. Demo below!

Added octahedrons to experiment with them as a digging primitive and ran into an issue when getting "corner radius" working. This is the fixed version - very satisfying :) (explanation below) 1/

Experimenting with "digging" using rotated cubes as the subtraction primitive instead of spheres. I like the jagged/angular/detailed look, but I'm going to try other shapes (like tetrahedron or pyramid) that aren't all right angles.

Added "corner radius" / rounding, which is easy to apply to any SDF shape that has an exact (outer) distance function - just subtract the radius from the scale and then offset the computed distance by the same radius. So you get rounded shapes "for free" with 1 subtraction. 1/

Made it seamless to switch between "edit" and "play" modes in my engine - toggle between them instantly with a shortcut. Super low-friction, and feels good! Granted right now "play mode" lets you walk around and that's about it :D

Another very cool alpha-to-coverage WebGPU demonstration. This one actually will test the A2C sample thresholds / dithering on your GPU and generate shader code to emulate it! (scroll to the bottom of the right pane) kai.graphics/alpha-to-cov...

Got a character controller working using Jolt's kinematic controller with simple WASD movement and a "jetpack." Works pretty well out of the box! Makes the world feel a lot more concrete.

Highly recommend both of these "Teardown frame teardown" articles. The Teardown renderer is pretty unique and there is a lot of food for thought in how it does things. acko.net/blog/teardow... juandiegomontoya.github.io/teardown_bre...

I enjoy reading old real-time rendering presentations where they talk about wanting rendering API / GPU features that weren't out yet.

This article (and associated sample app) by Matt Pettineo is getting old, but it's such a valuable resource on (cascaded) shadow mapping techniques. So valuable to compare techniques and tweak settings in the sample app. therealmjp.github.io/posts/shadow... github.com/TheRealMJP/S...

More ChatGPT hallucination hilarity - it links to a gdcvault.com talk, using the numerical id of an actual talk but changing the talk name in the URL (that's cosmetic only) to a different name than the actual talk. (And says it has a different speaker as well.) Sigh.

I am intrigued by the approach to directional shadow maps described in this presentation - in particular, cascades are cached world-space regions centered around the camera (not view-dependent). Are there other resources on this type of technique? www.youtube.com/watch?v=0QYE...

If you want to go even deeper down the depth buffer precision rabbit hole, this article is great: zero-radiance.github.io/post/z-buffer/

I like taking the laziest / most-minimal-possible approach to development. E.g., right now I test rendering changes by taking before/after screenshots, dragging them into Chrome and flipping back and forth with keyboard shortcuts. Would this work on a huge team with a 10-million

Better demonstration of the new (screen-space) ambient occlusion effect. Always satisfying to see lighting update with dynamic geometry modifications.

Nice li'l new video covering (some of) the history of SSAO algorithms: youtube.com/watch?v=g4or...

I spent way too long getting this ambient occlusion effect working. Subtle, but grounds objects, especially when they're moving. I ended up using GTAO, using an implementation based on Intel's XeGTAO: github.com/GameTechDev/... Still need shadows :)

It's cool that Chrome's new renderer/rasterizer (Graphite) is using Dawn (Chrome's WebGPU implementation) as its GPU abstraction layer. "Dogfooding" it like this means they're going to be extra-serious about perf/features/etc. blog.chromium.org/2025/07/intr...

Currently reading 🫠

It's kinda wild how deep of a rabbit hole each sub-area of rendering/graphics is. Currently looking at state-of-the-art SSAO implementations. VBAO ("visibility bitmask ambient occlusion"), which is like a 4th-gen technique, is promising. It's implemented in Bevy in 3 passes:

This is hilarious - ChatGPT hallucinates repeatedly about a nonexistent feature on another website (confusing people), eventually leading the site's owners to implement the feature. www.holovaty.com/writing/chat...

Have been using RenderDoc more recently - and boy is it useful :D Here I'm toggling through the draws of SDF bricks for each successive clipmap level (you can see the brick meshes). You can see frustum and occlusion culling in action. (Pic of the scene in next message.)

Moved to deferred shading because I want to have SSAO output (which needs depth + normals) be an input to shading. The G-buffer is very small for now - just 7 bytes of base-color (3 bytes), roughness (1 byte), and normal (3 bytes, octahedral-encoded). Performance is neutral!

A little added bonus of using WebGPU is that you learn about a lot of little quirks that differentiate the graphics APIs it supersets (Vulkan, DX12, Metal). In general, I think the API is well-designed when you take into account all of these details, which constrain it a lot.

A single slice of the (3D) SDF brick texture atlas I'm using. Each brick is 8x8x8 and stores a single 8-bit local signed distance. Doesn't look like much, but does a lot of heavy lifting!

Selecting different skybox/lighting presets.

My engine doesn't currently support baking "metallic" into the SDF, but I can tweak a number in the shader to make everything metal 🤘🤘 I feel like I can hear a "clank" when shooting this stuff.

Finished implementing diffuse and specular image-based ambient lighting, and things are looking a lot nicer. This is still without any shadows or AO, so that's next! I also switched to using ACES for tonemapping, which is similar to what I had before but seems a bit nicer.

And the sequel... www.youtube.com/watch?v=PCmn...

WebGPU train finally leaving the station - now Firefox is shipping! (on Windows to start) "On behalf of Mozilla's WebGPU team, I intend to let WebGPU ride the trains to release in Firefox 141 on Windows." groups.google.com/a/mozilla.or...

This article is really insightful sergeylevine.substack.com/p/language-m...

How to render a skybox cubemap with a single triangle: 1. Draw a "fullscreen triangle." This can be done with vertex shader code (see below), no vertex attributes required. 1/

Nothing like needing to learn about a new file format and write a bunch of code to get all its bits and pieces in the right place to grind project momentum to a halt...

Holy shit, I am just catching up with this article, which goes way further down the mipmap filtering rabbit hole than any other resource I've seen, including showing differences in GPU vendor hardware implementations. pema.dev/2025/05/09/m...

I've been looking at LinkedIn a bit more in the last few days. And it's hilarious how everyone is writing in the same breathless, one-sentence-per-paragraph style. Do they write like this? Yes. They do, and so can you.

Excited to finally show off Nanite Foliage www.youtube.com/watch?v=FJtF...