Taking another look at the morton order code @vassvik.bsky.social posted, one can further reduce the amount of instructions required, using one of my favorite bit fudging techniques: Bit cloning using multiplication! It sometimes lets you replace code like x | (x << a) | (x << b) if a, b are fixed.

Some random Morton Code tricks: If you've worked with Morton codes you've probably seen something like the this GLSL code to decode a Morton code, which end up at roughly 27 integer operations to generate the equivalent 2D position. Code transcribed from fgiesen.wordpress.com/2009/12/13/d...

Decided to go back to making Shadertoy fluid sims for for a bit. This time I improved my particle clustering cellular automaton SPH fluid sim to support multiple species particle merging and splitting. Also some fine tuning of the physics. shadertoy.com/view/tfyyWD

Announcing: New @steampowered.com Hardware, coming in 2026: Steam Controller Steam Machine Steam Frame.  Watch our jazzy announcement video and wishlist now: steampowered.com/hardware

Had this knocking around in my head for about 6 months and finally got around to writing it out and filming it. This is my first time making a video essay and I haven't written VO since college but I'm happy with how it came out. Let me know what you think! Filmed in #vrchat Edited with #blender3d

If you own a robotic arm, other users can now remotely move it with standard DPS or SPS lights, using this new open-source software that I am releasing today. No special setup is needed from the other users. If they already have lights, they can control it, no program necessary.

what if your avatar's minimum brightness was set to zero, it'd be pretty cool

Been playing with some wetness effects for a #VRChat world recently. Took the math of @mochie.bsky.social 's water gerstner waves, rendered it to a texture, and then did some simple decay on it via Graphics.Blit. Its a little jank but I've stared at it long enough that I think its working #unity3d

Light Volumes v.2.0.0 released! Now it has Light Volume based super optimized analytical Point Lights, Spot Lights and Area Lights. (Up to 128 at the same time) Ability to project images and cubemaps. Also baked shadow masks and even more features! github.com/REDSIM/VRCLi...

The hair has to make way for the cuddles.

I made a video about my (extremely crude) software rasterizer. You can watch it over here! youtu.be/yyJ-hdISgnw?...

Technologies change, the problems stay the same. Was trying to improve the results with @sim.red Light Volumes Original clip by @crowscrowscrows.com #unity3d

I have updated Lightbox Viewer to V2.4.0: - Added new specialized lightboxes. They will only appear if the Light Volumes package is installed. - Lights inside the avatar are no longer disabled by default. - Add support for Poiyomi SSAO and similar effects.

I made my fluid sim particles got towards the nearest light from the light volumes. youtu.be/i8PFoagQhP0

Adding the vrc light volume support to my raymarcher was slightly less trivial. The reason being that the self reflection rays for the metallic parts need to sample them a second time on their ray hit. Still pretty easy tho and definitely worth it.

I've been trying out @sim.red VRC Light Volumes on a bunch of my shaders. It looks really good especially on larger things like my pool. Really grounds the thing in the world.

I wrote a blog post about mipmap level selection. pema.dev/2025/05/09/m...

I am releasing "Skinned Mesh Constraint Builder". Avatars like Milltina are weight painted in such a way that attaching objects or particles to the body isn't as straightforward as parenting to one bone. Use this tool to attach a GameObject to a polygon, like weight painting.

Variant.

VRC Light Volumes is a next-gen voxel based baked volumetric lighting solution for VRChat, I'm working on right now! It affects avatars, dynamic props, etc. Works really fast without major overhead even on Quest. It will be fully open-source and free, so stay tuned! #vrchat #gamedev #shader

I've been improving my VRChat liquid simulation for the last few weeks. Of the most notable things that I've implemented is a ray tracing algorithm over a 3d texture isosurface (using some ideas from jcgt.org/published/00...) Its surprisingly performant for VR resolutions!

I'm slowly porting my approximate grid SPH simulation to VRChat. It did require few improvements to be stable enough, now its a hybrid neighbor index/particle average grid. Still need to implement @d4rkpl4y3r.bsky.social 's mip counting sorting method for improved performance.

VRChat has released Steam Audio into the Open Beta. The website has been updated with a new counter: issteamaudiooutyet.com #VRChat

I usually render particle fluids with particles, as it gives the most details, but here I tried using ray marching for the fluid. It certainly is much more liquid like, but at the same time its slower and loses some detail. I wonder if I can improve this. compute.toys/view/1809

Been recently looking into fluid simulations again. This time I've testing if I can make a good SPH simulation but only having "average" cell particles. It seems to work surprisingly well, and it doesn't need sorting either. compute.toys/view/1782 Explanation thread👇🧵

I'm finally adding fluid spawn and void to my SPH sim. Now that I actually kinda understand what the sim parameters mean I managed to make the per step particle spawn rate adjust to match the target rest density. youtu.be/xX0DqvNhimc

Today I uploaded my Powder Toy in #VRChat creation as a world, so people who don't know me can play with it: vrchat.com/home/launch?... I also added 10 new elements, including a bunch of explosives which can push around particles when detonated, via a rudimentary wind simulation.

I made Powder Toy in VRChat! It supports several kinds of liquids and solids, including chemical reactions between them. It's done entirely with fragment shaders and cameras, so I can put it on my avatar.

I made water. I want to drink it. 🧵1/4 #VRChat #Shaders #VRChatWorlds

I've been doing some more fluid sim experiments lately, and just uploaded a video about it! youtu.be/8nIB7e_eds4

I just released Orbs! Orbs is a very relaxing AR game for Meta Quest 3 and 3S where you can immerse your hands in a massive pile of 1000s of colorful orbs. Please check it out! www.youtube.com/watch?v=9XBq...

Just did a little test and it turns out you can do the "fast mmap Ring-Buffer"-trick in #vulkan by using Sparse Memory Bindings and aliasing the same page of GPU-Memory multiple times.. Just did a little test and it worked just fine on AMD and NVidia! #programming

I manage to untangle my fluid sim parameters. To make it work all the way back I did such cursed things as split particle mass into two different values. This video shows the new values up top and the old ones at the bottom. It matches it pretty closely. www.youtube.com/watch?v=PTFP...

This is sooo much better to play with in vr. And it was already fun in editor. Its just so satisfying.

Hmmm, invisible grape juice.

Touch the balls. Now to figure out what to actually do with this...

wiggle update to dildo.shader

Hi #VRChat ! Just recently had people that were curious about my workflow for avatar optimization and figured it was the best time to share it. Keep in mind, this is *my* workflow and that doesn't mean it's the best, but this really works for me! Here's a thread! 🧵