Matt Pfeiffer ᯅ

PLY to RealityKit with Grid-Based Decimation (Example: HD Skeleton Scan) PLY to RealityKit with Grid-Based Decimation (Example: HD Skeleton Scan) - ModelIOLoader.swift

gist.github.com/Matt54/f001a...

RealityKit experiment #81
(code in the replies)

I found a scan of a human skeleton and wanted to try to visualize it in RealityKit. The PLY file had millions of triangles, so I had to decimate the mesh. It ended up being really satisfying to see the wireframe at different LODs

Thanks Clem! I would love to see that Gaussian Splat example

RealityKit SDF Falling Sand Animation (Metal + LowLevelMesh + Marching Cubes) RealityKit SDF Falling Sand Animation (Metal + LowLevelMesh + Marching Cubes) - EasingCurve.swift

gist.github.com/Matt54/afc92...

RealityKit experiment #80
(gist in the replies)

LowLevelMesh “Falling Sand” dissolution and reassemble effect created with SDF shapes and Marching Cubes. A Metal compute shader uses a spatial sweep to "release" triangles that rigidly start to fall

RealityKit Extruded Text to LowLevelMesh animated by Metal compute shader RealityKit Extruded Text to LowLevelMesh animated by Metal compute shader - ExtrudedTextLowLevelMeshView.swift

gist.github.com/Matt54/44177...

RealityKit experiment #79
(code in the replies)

Animating 3D text by converting the output of MeshResource(extruding:) to a LowLevelMesh and applying a Metal compute shader

The MeshResource was interesting to unpack since it had multiple models/parts plus instance transforms

Thank you! 🙏

RealityKit Explode and Assemble SDF Shape (Metal + LowLevelMesh + Marching Cubes) RealityKit Explode and Assemble SDF Shape (Metal + LowLevelMesh + Marching Cubes) - EasingCurve.swift

gist.github.com/Matt54/87edc...

RealityKit experiment #78
(gist in the replies)

LowLevelMesh explode-and-assemble animation created by meshing an SDF using Marching Cubes and rigidly pushing it’s triangles outward

RealityKit Color-Blending Metaballs (Metal + LowLevelMesh + Marching Cubes) RealityKit Color-Blending Metaballs (Metal + LowLevelMesh + Marching Cubes) - MarchingCubesColorBlobParams.h

gist.github.com/Matt54/bcc31...

RealityKit experiment #77
(gist in the replies)

Color-blending metaballs created from animated sphere SDFs via Marching Cubes. LowLevelMesh vertices store per-vertex color in the Geometry Color vertex attribute, read by ShaderGraphMaterial

Ahhh, well I love that description 😆

Is it the room?

RealityKit Marching Cubes Blob (Metal + LowLevelMesh) RealityKit Marching Cubes Blob (Metal + LowLevelMesh) - MarchingCubesBlobParams.h

gist.github.com/Matt54/1a506...

RealityKit experiment #76
(gist in the replies)

LowLevelMesh blob from meshing the smooth-min of animated sphere SDFs with marching cubes. Glassy ShaderGraphMaterial is based on Apple's "Implementing adjustable material" sample

Haha exactly 😆

gist.github.com/Matt54/aec7d...

RealityKit experiment #75
(gist in the replies)

LowLevelMesh shape shifting by interpolating between two signed distance fields and meshing with marching cubes

Marching Cubes Metaballs in RealityKit (Metal + LowLevelMesh) Marching Cubes Metaballs in RealityKit (Metal + LowLevelMesh) - MarchingCubesParams.h

gist.github.com/Matt54/881d7...

RealityKit experiment #74
(gist in the replies)

- LowLevelMesh with disconnected geometry
- Marching Cubes + SDF for vertex positions
- Vertex normals from SDF gradient
- Polynomial smooth-min to blend the shapes

RealityKit burn fade sphere: LowLevelMesh, ShaderGraphMaterial, and compute shader RealityKit burn fade sphere: LowLevelMesh, ShaderGraphMaterial, and compute shader - BurnFadeParams.h

gist.github.com/Matt54/bf9d1...

RealityKit experiment #73
(gist in the replies)

Here's a simple burn fade example. The ShaderGraphMaterial directly sets the color and opacity from the UV2 attribute of the LowLevelMesh vertices and the Metal compute shader updates those color/opacity values

Yeah that makes sense

The idea came to me while building a glowing torus for a project and I just wanted to see how it would look as a spinner. Performance is probably not good 😆

RealityKit LowLevelMesh Glowing Torus Spinner RealityKit LowLevelMesh Glowing Torus Spinner. GitHub Gist: instantly share code, notes, and snippets.

gist.github.com/Matt54/20595...

RealityKit experiment #72
(gist in the comments)

LowLevelMesh Torus Spinner
- incrementally adds vertices/indices (or shifts the indexOffset when removing)
- multiple layers of varying opacity and minor radius are stacked with additive blend mode for the glow effect

Burn Fade Animation for USDZ Models in RealityKit using LowLevelMesh, ShaderGraphMaterial & Metal Compute Shader Burn Fade Animation for USDZ Models in RealityKit using LowLevelMesh, ShaderGraphMaterial & Metal Compute Shader - BurnFadeModelView.swift

gist.github.com/Matt54/a9d12...

RealityKit experiment #71
(gist in the comments)

- Loads mesh & texture from USDZ
- LowLevelMesh verts use float4 color+alpha in uv2
- ShaderGraphMaterial blends texture with uv2.rgb, sets opacity from uv2.w
- Metal Compute Shader animates uv2

@vrhermit.com but that's only on the growth animation of the mesh. If you kept the mesh quality low and didn't care about the growth animation, you could probably go really high! You would just need to replace the incremental growth implementation with an algorithm that calculates the end state

There's currently a bottleneck on the CPU-side that would prevent you from going too high (how high depends on the mesh quality), but I was thinking about trying to combine this idea with MeshInstancesComponent to create a field of grass since it's all one mesh