Procedural Heartbeat – Organic HLSL in UE5

The project focuses on a mesh-based single procedural material of a horror tentacle. No baked textures for veins, eyes, or surface deformation - everything generated in-shader. Inspired by the eyed tentacles from Cult of the Lamb, I aimed to recreate the Ichor effect entirely in Unreal Engine using a single material.
WPO combines six animation layers: S-curl pre-bend, primary bend with lateral sway on non-rational frequency ratio for non-looping motion, asymmetric breathing pulse, tuck contraction, micro vibration, and tip falloff that keeps the spike static while the body breathes.
Veins are Voronoi-based: edge distance between two nearest cell points defines the network, with seamless cylindrical wrap, flow drift, and pulse phase traveling along the structure. Same math drives both emissive glow and vertex inflation for real surface volume.
Eyes are an SDF composite on a procedural grid - eye shape from two offset circles, vesica-piscis vertical slit pupil, hash-driven saccade and blink, per-cell variation in size, rotation, position, and phase. WPO bulge + tangent-space fake normal give true volume with smooth highlights.
A Material Parameter Collection ties everything to a single organic Heartbeat value - pupil dilation, vein intensity, and field-wide pulse all breathe in sync. Vein system carves an exclusion mask around eye zones.
The whole effect scales through parameters and works on any spherical or conical mesh - built as a reusable corruption-biome pipeline rather than a one-off asset.
Beyond the main scene, the SDF eye system was repurposed as a particle effect, and six-way lighting dust and smoke add atmospheric ambient depth.
Production pipeline: ground destruction simulated in Houdini and exported as fractured static mesh with VAT. Full scene assembled in Sequencer.