Fast Infection — instant infection spread for meshes and point clouds

• 2 min read

Most “infection” or “spread” setups need a full simulation — slow, needs a cache — or only work on connected polygon meshes. Fast Infection does neither. The whole arrival field is solved once, up front, so there’s nothing to bake and nothing to re-simulate when you tweak a keyframe. Scrub Growth from 0 to 1 and watch the spread unfold instantly.

What it does

  • Instant scrubbing — Growth is a threshold sweep over a field solved once. Move the slider, see the result.
  • Works on point clouds, not just meshes — scattered points, a particle sim’s output, anything with no connectivity at all. Fast Infection builds a temporary neighbour graph, solves on it, and hands back your own points with the result.
  • Organic, not uniform — a noise-warped speed field, with amplitude, element size, a paintable speed mask, and directional bias (creep like a drip, or climb like vines).
  • Four ways to seed the start point — a point group, explicit point numbers, a second input, or random. Second Input can seed by snapping to the nearest point, or (new in 1.1) seed every point enclosed by input 2’s mesh — drop a sphere over part of your model and the whole enclosed patch ignites at once.
  • Seven visualize modes, including Contour Rings for reading exactly how the noise is shaping the front.
  • Never fails silently — disconnected islands or points a speed mask has walled off are flagged with a warning, a group, and a count.

Requirements

Houdini 21.0 or 22.0. Built entirely from stock SOPs — no paid add-ons, works in every license tier including Indie.

Download

Get Fast Infection

Installation

  1. Download EMILSVFX-Fast_Infection-1.1_blackbox.hdalc
  2. Drop it into your houdini21.0/otls/ (or houdini22.0/otls/) folder
  3. Restart Houdini, or File → Asset Manager → Install New Asset…
  4. Tab menu → type “fast” → Fast Infection (EMILSVFX submenu)

One license per seat, unlimited personal or commercial use, no reselling or redistributing the asset itself. Questions or feature requests: emils.vfx@gmail.com