broken hash function

my uber shader will be perfect after one more ground-up rewrite. for real this time.

happy accidents

Looking up through the bottom :) Underwater volume rendering soon (tm)

screen-space refraction :D 3x 1-meter steps with linear interpolation between last two samples upon overshoot. #unity3d

revisiting fft water. I finally reined in aliasing by smoothstepping out cascades based on their minimum feature size. #vrchat #unity3d

behold: a chair - make high poly model with array+curve - unwrap, bake ao @ 4k - make low poly bounding box - bake diffuse & normal with selected to active @ 2k 3k tris at the end. #blender3d

why is my laptop burning my thighs #blender3d

day 1 roughing out hemi octrahedral impostors based on ryan brucks’ blog post. Very bad popping, unlit, no depth or normals. For the life of me I can’t figure out the parallax correction he does….

TIL about octahedral mapping - a method to convert between a flat plane and a (lightly distorted) sphere or hemisphere without any trig operators. Mocked up with my overengineered autodiff vertex deformation framework. #unity3d #shaders

screwing with grass. no sway or impostors yet. 40k instances, 125 blades of grass per instance, 10 triangles per blade. the only clever bit is caching. as the player moves, you compute new grid cells. do not even iterate over old cells - it's too slow. #unity3d

first end to end proof-of-concept of a vertex deformation animation system i'm working on. the shader has 16 slots for deformation operators. it uses dynamic branching to dispatch each operator. the beauty is that the operators can be dynamically reordered and duplicated. #unity3d

fucking finally the "undo" steps are actually independent operators. i'm not just, like, moving t back to 0. i can put this on a torus mesh, unwrap into to cartesian space, apply deformations, then re-wrap to toroidal space. fallback shaders see a torus. full shaders see a ~fancy~ torus

vertex deformation shaders are a vicious linear algebra skill check

how much rust do you have to write before you’re compelled to describe every project as blazing fast 🔥🚀

blender 4.5 nodes to create a truss. it samples a pair of curves and connects corresponding sample points with a cylinder. #blender3d

i think ray marching on a deformed surface is completely ironed out now! specular is pointing the right way, it doesn't fall apart with extreme deformations, and i can chain together several deformations. #unity3d #simulation

generalized norm mapping c:

i finally got this ~working: ray marching on a deformed surface. ray marching requires a euclidean distance metric to converge quickly. the idea here is to deform the surface (ro) and the incident vector (rd) using the deformation's jacobian. the march then runs in a locally linear space. #unity3d

using nvidia's slang language + compiler to automatically differentiate a vertex deformation shader. this lets me completely skip the process of manually computing the jacobian of a vertex deformation. analytic normals without any of the legwork! #Unity3D

I ported my water spectrum code to C# and made an automated build script. Spectrum generation, FFT pipeline setup, and hooking into the surface shader is all automated now. The number of cascades, their scale, and all physical parameters are now configured in one panel. #unity3d #simulation

I added physically accurate viscosity term to my water sim. Cold ocean water typically has a viscosity around ~0.077-0.079 N/m. This video shows 0 N/m, 1 N/m, then 50 N/m. #Unity3d #simulation

NSFW/WIP. I'm really pleased with how the topology turned out on this asset I'm working on. I drew the seams with the grease pencil, then made a topology around them. Making all the structures for a base to deform well, while also adhering to the seam design, is a fun challenge.

hand retopology study :) I'm getting a little better at the islanding workflow. the goals were to have nice edge flow around seams, holding edges on all major features, and 100% quads. two 6-poles snuck in, unfortunately.

messing with hypotrochoids again :) multiplying radius by theta gives interesting results #Unity3d

Cloth! I added a cloth lobe using Estevez et. al. "Production Friendly Microfacet Sheen BRDF." I also wrote a little monte carlo integrator to bake energy compensation textures for image-based lighting. #Unity3d

i added clearcoat to my brdf today! #Unity3d

more work on the fft water :) - 4 cascades - sea foam - view dependent subsurface scattering approximation - distance based tessellation and proper culling - new purpose-built brdf ~1.5ms on the gpu. #unity3d #vrchat

fft water wip :) all heavy lifting is done on the GPU. I'll chase down bugs with the normals before adding cascades and water-specific lighting effects. #unity3d #vrchat