Anna Komitska




Procedural Ivy Generator

Type:
Procedural foliage tool, cinematic
Year:
2026
Software:
 Houdini, Unreal Engine 5.6, Nuke, Davinci Resolve


A procedural ivy generator built in Houdini. Designed as an HDA for real-time use in Unreal Engine.

The tool has been showcased within the Dark Ruins Megascans sample. Set dressing has been adjusted for each shot.

Lighting rigs have been set up with physically-based values. Lens artefacts are comped in Nuke, and the grade has been handled in Davinci Resolve.

Scroll down for key features.





Key tool objectives:


  • Build up individual layers of branches with a focus on the overall shape language of ivy as it crawls over underlying surfaces;

  • Multi-layered dense branch and leaf clumps to add volume to the wall’s profile;

  • Art direct ivy that hangs off through gaps and/or hits perpendicular surfaces.


In development (coming soon):


  • Versatile leaf system adjustments to generation, texturing and topology.









Current tool features:

Branch generation


  • Shortest path-based branch growth
  • Ground cover ivy spreading onto surrounding terrain with bounding box-clipped landscape for performance
  • Mask-driven scatter using combined AO, noise, and density maps
  • Vertex colour painting support from Houdini and Unreal to include / exclude areas
  • Curve input for guided ivy path placement
  • Branch clumping via 3D noise
  • Multi-layer ivy generation for dense growth
  • Hanging vine generation on downward-facing and vertical surfaces with controllable probability
  • Vine re-attachment to perpendicular surfaces with angle threshold control
  • Branch pruning with seed control
  • Automatic cleanup of disconnected and wall-intersecting branches

Branch appearance


  • Parametric branch width along tangent
  • Left / right alternation with dead zone control
  • Hanging branch tilt away from wall with distance-based falloff
  • Noise-driven vine displacement with pin ratio control
  • Bottom cut-off with noise-driven threshold
  • Extend generation over ground surface with gradient blend

Leaf system


  • Surface normal and tangent-based leaf orientation and tilt away from wall for near-surface leaves
  • Left / right alternation with controllable angle
  • Leaf size tapering towards the tips
  • Random noise size variation
  • Leaf sliding along branches
  • Trim control for branch tips and roots
  • Overlap threshold detection and pruning between adjacent leaves and at fork points
  • Per-leaf wind gradient and intensity variation in vertex colour for Unreal material WPO

Leaf card pipeline


  • Switch between traced mesh leaves and UV atlas cards for performance
  • Procedural atlas cutting with automatic UV assignment and ability to select leaves to use
  • Per-leaf procedural bend deformation
  • Global noise-driven scale variation