Hydra

Hydra is a generative artwork exploring the dynamic evolution of river deltas—natural systems that have shaped and mirrored human civilization for millennia. From the earliest settlements in Mesopotamia to the modern megacities of the Nile and Pearl, deltas have served as fertile grounds not only for agriculture, but for the growth, division, and migration of entire societies.

The series takes its name from the Lernaean Hydra, a mythological creature whose severed heads would regrow as two, reminiscent of the perpetual avulsion and bifurcation of the river channels within a delta. The algorithm behind Hydra procedurally generates deltaic topographies by stochastically routing water and sediment parcels, with the degree of sediment cohesion influencing whether a delta meanders or fans outward. Like human cultures, these formations grow, split, and migrate, shaped by internal dynamics and external forces alike.

Once generated, the topographic map of a delta is rendered as layers of pigments on rough paper, sometimes arranged as a triptych portraying its evolution in thirds. The visual treatment of Hydra draws on diverse sources of inspiration ranging from the vibrant waterways featured in Poisoned Beauty by Gheorghe Popa to the watercolor aesthetic of GRIS by Nomada Studio.

In tension between chaos and control, erosion and emergence, Hydra invites viewers to consider the parallels between the physical evolution of landscapes and the social structures that grow upon them.

Hydra adapts "DeltaRCM Vegetation" by Rebecca Lauzon (MIT), "D3.js" by Mike Bostock (ISC), "Spectral.js" by Ronald van Wijnen (MIT), and shader fundamentals by Dave Hoskins (MIT) and Inigo Quilez (MIT).

Release

Hydra is a planned submission to Art Blocks.

Prints will be available for Hydra owners at a set price. Three-dimensional depth maps made of birch wood each of the river delta depicted in a Hydra piece will likewise be available for a set price. A depth map of the example piece at the top of the page is shown above.

Deltas

The river delta in each Hydra piece evolves from a river flowing into a rectangular basin, with the deposition and erosion of sediment carried by the river, a mixture of mud and sand, simulated with an accelerated implementation of the model described in Liang et al. (2015). This model repeatedly computes weighted random walks (shown in white above) of numerous water and sediment parcels and updates the water surface elevation and bed topography accordingly with distinct rules for cohesive and noncohesive sediment (described as mud and sand respectively).

Contours

The river delta is generated on a rectangular grid, so portraying its topography requires generating contour polygons corresponding to a linear sequence of depths between the basin and surface. The contours are calculated via marching squares, which is computationally faster than the delta generation timesteps, allowing them to be displayed as the delta is generated. The contours are colored in a gradient from the piece's primary color below basin depth to white at the surface.

Pigments

After the river delta is generated, the rendering process begins by calculating the intensity of pigments across each contour. In accordance with watercolor paint, the intensity is higher closer to the border of a contour, particularly at its hard edge. Pigment intensity as well as interpolation between the primary and secondary pigments are, among other components of the rendering step, modulated with fractal noise. The pigments in each contour are then layered with realistic Kubelka-Munk color mixing.

Texture

The final step is rendering the pigments onto a rough paper texture, involving a few techniques working together. After generating a paper texture, the pigments are slightly warped toward indentations in the texture and slightly intensified in the indentations to mimic the movement of paint. An angled light source then casts highlights and shadows across the texture. This brightness modulation is restricted to the contours to retain flat white space.