Active Finite Voronoi Model

Huang, Levine, Bi · Soft Matter 19, 9389 (2023)
JS port of pyafv by Wei Wang & Brian Camley
-- fps
⟨A⟩ ⟨P⟩ arc frac ⟨|v|⟩ steps 0
About this model

This demo is a JavaScript port of pyafv, the open-source Python implementation of the Active Finite Voronoi model by Wei Wang and Brian Camley (Johns Hopkins).

Active Finite Voronoi (AFV). Each cell is the Voronoi region around a self-propelled point, intersected with a disk of radius ℓ. Boundaries are a mix of straight edges (shared with neighbours inside range ℓ) and circular arcs (cell–medium interface).

Energy: E = Σ [Kₐ(A−A₀)² + Kₚ(P−P₀)²] + Λ · L_arc. The line-tension Λ on non-contacting arcs controls adhesion/cohesion; at small Λ cells detach and fragment, at large Λ the tissue stays confluent.

Unlike confluent Voronoi/vertex models (like SPV), AFV allows free boundaries, detachment, and fragmentation — bridging cohesive tissues and isolated motile cells.

Model Parameters
interaction radius
Maximum cell radius; isolated cell is a disk of radius ℓ
1.00
A₀preferred area
Default π (matches ℓ=1)
3.14
P₀preferred perimeter
Shape index p₀ = P₀/√A₀
4.80
Λarc tension
Line tension on cell–medium edges
0.20
v₀self-propulsion
Motility speed
0.05
Dᵣrotational noise
Persistence time τ = 1/Dᵣ
0.10
Phase Presets
Default (cohesive)
Detaching (low Λ)
Confluent (high Λ)
Active fluid
Fragmenting
Simulation
N cells
Steps / frame: 1
Visualization
Cell boundaries
Cell centres
Polarity arrows
Interaction range (ℓ)
Color cells by
contact (arc frac)
area
speed
polarity
References

This demo is a JavaScript port of pyafv, the open-source Python implementation by W. Wang and B. A. Camley:

[1] W. Wang and B. A. Camley, Divergence of detachment forces in the finite Voronoi model, arXiv preprint arXiv:2604.15481 (2026).   [GitHub]

[2] Huang, J., Levine, H., Bi, D. Bridging the gap between collective motility and epithelial–mesenchymal transitions through the active finite Voronoi model. Soft Matter 19, 9389 (2023).

[3] Teomy, E., Kessler, D. A., Levine, H. Confluent and nonconfluent phases in a model of cell tissue. Phys. Rev. E 98, 042418 (2018).

Disclaimer
This demo was developed with assistance from AI coding tools. Forces are computed by numerical finite differences of the total energy, not by the analytical derivative machinery in pyafv. Treat results as illustrative, not authoritative; consult the cited references and pyafv for production simulations.