Paint that behaves
like actual paint.
Helios isn’t a set of brush stamps that imitate media. It’s a real-time simulation of pigment, water, and oil — flowing, mixing, and drying on a physical canvas. Built for concept artists and professional digital painters who want the medium to push back.
A wet, living canvas — solved every frame
Under the surface, a GPU fluid solver runs the same model from delicate ink wash to heavy impasto. Water carries pigment, evaporates, and leaves granulation in the paper’s tooth. Oil piles into ridges that catch the light.
Fluid dynamics
Pressure-driven flow, diffusion through wet regions, and evaporation that precipitates pigment into the substrate — true watercolor blooms and backruns, not textures.
Layered impasto
The viscous model stacks paint in real layers. Cross a thick stroke over another and the upper paint sits proud — raking light reveals genuine topography.
Real bristle brushes
Over a thousand individual bristles per brush pick up, drag, and release paint — splaying under pressure and carving furrows the way a loaded brush actually does.
Old pigments, new mathematics
Every color in Helios is a pigment with physical behavior — and every medium is a coordinate in one continuous simulation, not a separate tool.
A continuous map of creative terrain
Helios doesn’t ship a watercolor tool and an oil tool and a pastel tool. A single simulation governs every medium — and the difference between a translucent ink wash and buttery impasto is just a position in a continuous parameter space. There are no hard edges between media, only terrain to explore.
- Wetness, viscosity, pigment load and more, all freely adjustable
- Slide from watercolor to oil and watch the paint transform in real time
- Find your own regions between the named media that no tool would have given you
Mix like pigments, not like pixels
Most software blends color by averaging screen values — mix blue and yellow and you get mud. Helios mixes the way real paint does, simulating how each pigment absorbs and scatters light across the full visible spectrum.
- Kubelka–Munk pigment mixing across 31 spectral bands
- CIE 1931 color matching for true-to-eye rendering
- Blue + yellow makes green — exactly as on a real palette
The paper fights back
Every canvas is a procedurally generated fiber matrix with real tooth, absorbency, and grain. Choose your surface and the paint responds — pooling in the valleys, catching on the peaks, darkening at drying edges.
- Cold-press watercolor paper with strong granulation
- Woven cotton & linen canvas for oil and acrylic
- Handmade rag paper with visible curling fibers
Watercolor solved by the actual physics
The wet phase isn’t a diffusion blur dressed up to look like paint. It’s a real-time Navier–Stokes solver running on your GPU — the same equations that govern any incompressible fluid, applied to water carrying pigment across a porous substrate.
VORTICITY IS PRESERVED — ROTATION PERSISTS INSTEAD OF DECAYING TO A SMOOTH BLUR.
Coffee-ring darkening perimeter evaporation
Wash edges lose water faster than the interior (more air contact per unit volume). Carrier flows inward-to-outward to refill the rim, carrying pigment that strands there as it dries — the classic dark tide line around a drying wash.
Granulation discrete pigment grains
Pigment is simulated as individual grains advected by the flow, not a smooth concentration. They settle into the paper’s tooth and collect in vortex cores, giving the speckled, mottled texture of granulating pigments.
Blooms & backruns drying-front instability
Drop fresh water into a half-dry wash and it shoves the settling pigment outward, blossoming into the feathered cauliflower edge every watercolorist knows — emergent from the flow, never stamped on.
Curling wakes & eddies conserved vorticity
Because the velocity field is projected divergence-free, rotation survives. Fast brush motions trail recirculating wakes and wet pools swirl with eddies, instead of relaxing instantly to a flat gradient.
Pooling & tide lines hydrostatic pressure
Paint height feeds a pressure source term, so thick puddles push outward from their deepest point. Pigment piles up and darkens where the flow stalls at a drying boundary.
Fiber wicking substrate-guided tendrils
At the wet front, pigment particles spawn and travel along the substrate’s fiber directions, dragging color into the paper as feathered tendrils that follow the grain — the way ink wicks into real fiber.
Four brushes, four temperaments
A brush isn’t a stamp — it’s a physical object with a will of its own. Helios ships four brush engines spanning a spectrum from exact control to wild, expressive character. Pick the one that suits the mark you want to make.
Cosserat rod the real one · most realistic
Each bristle is a continuum elastic rod that bends, twists, and springs back like an actual hair. The most physically faithful brush in Helios — every nuance of pressure, drag, and release lands in the mark. This is the gold standard.
Inverse kinematic swishy · a different character
Driven by an IK chain rather than raw bristle physics, this one has a loose, swishy response all its own — it flows and trails through a stroke with a distinct, lyrical feel, a world apart from the rod’s exacting fidelity.
Swarm controllable · least character
The closest thing to a traditional digital brush: a fixed swarm of bristles that tracks your cursor precisely. The most controllable and predictable of the four — when you want command and repeatability over emergent surprise, reach for this.
Verlet integration calligraphic · character over control
Verlet-integrated bristles carry real momentum and inertia, giving strokes a gestural, calligraphic life. The trade is control — like a real loaded brush it has a mind of its own, and learning to drive it is part of the craft.
Built for the way professionals work
A focused toolset that stays out of the way — so the painting, not the interface, is what you think about.
Many media, one engine
Ink, watercolor, gouache, acrylic, oil, pastel — and everything in between. Not a handful of presets, but a continuous space you dial into.
The Voronoi palette
An 80-cell mixing map: tap a cell to load it, and its color bleeds to neighbors with distance falloff. Mix new pigments simply by sampling between them.
Perceptual color picker
An OkLCh picker built for artists — adjust lightness, chroma, and hue in a space that matches how your eye actually reads color.
Reference on canvas
Drop reference images straight onto the workspace and sample directly from them while you paint.
Tool presets
Save any brush, its load, and its behavior as a preset. Build a personal kit and recall it in a click.
Export your work
Save sessions in Helios’s native format, or export finished pieces ready for portfolio and print.
First works from the studio
Three walls, reserved. The first paintings made in Helios will hang here — our first invited artists are at their easels now.
A real simulation requires a decent GPU
Helios runs a true physical simulation on your graphics card every single frame. That isn’t cheap, and we’re not going to pretend otherwise — the payoff is paint that genuinely behaves like paint. To feel it, you’ll want capable hardware.
A modern GPU
The solver lives on GPU compute. A recent dedicated graphics card is strongly recommended — the more capable it is, the larger the canvas you can paint in real time.
8 GB of VRAM or more
The simulation keeps large multi-field buffers resident on the GPU. We recommend at least 8 GB of video memory — and more headroom for big canvases.
Loves Apple Silicon
Helios runs beautifully on an Apple Silicon MacBook Pro — the unified memory and integrated GPU are a natural fit for the engine.
The studio is nearly ready.
Helios is in final preparation. Leave your email and we’ll let you know the moment the studio opens.