Distance fields & volumes
Two ways to describe shape in 3D: a live "how far am I from the surface" formula, or that formula frozen into a grid of voxels you can light up like smoke.
DNA gives you two related ways to work with solid, volumetric shape. They sound technical, but the idea behind each is simple — and you can flow freely between them.
A Distance Field is a "how far" formula
A Distance Field answers one question at every point in space: how far am I from the nearest surface? Inside the shape the answer is negative, on the surface it's zero, and outside it's positive.
Because it's a formula rather than fixed geometry, it stays perfectly crisp at any zoom and is wonderful for blending. Two distance fields can melt into each other, carve holes, or round their seams — all the smooth boolean tricks you've seen in fluid, metaball-style art.
A Distance Field is really just a kind of Fields (a value that exists everywhere in space). Many things in DNA can become one:
Analytic shapes — spheres, boxes, cylinders, tori and cones describe their distance with a tidy bit of math, so they stay exact. (See the "Analytical" toggle and the per-row @analytic attribute in Analytic shapes.)
A mesh — DNA measures the distance to the model's surface for you.
An image — a logo or mask becomes a distance field from its edges, great for outlines and glows.
Points — a cloud of points blobs together into one smooth surface, like droplets merging.
Distance fields shine when you want shapes to interact. Reach for one whenever you want soft unions, smooth subtraction, thickening, or shells.
A Volume is that formula baked into voxels
A Volume is a 3D grid of little cells — voxels — each holding a value. Think of it as a 3D image: where a photo has pixels across width and height, a Volume has voxels across width, height and depth.
You can bake a Distance Field into a Volume to "freeze" it onto a grid. You can also fill a Volume directly with density — the cloudy, foggy stuff that smoke and clouds are made of. Volumes are how DNA renders soft, lit, atmospheric things: smoke, fog, clouds, glowing energy.
The look of a Volume comes from its material — color, how much light it scatters and absorbs, a Gradient that maps density to color, and a touch of fine detail for wispy edges. The renderer adds self-shadowing, soft glow, and silver-lined rims automatically, so smoke looks believable out of the box.
A single-channel Volume can hold either a distance field or raw density — they look the same on the grid but render very differently. DNA tracks which one you've got, so a distance-field volume renders as a solid surface while a density volume renders as fog. You don't have to manage this by hand.
How they relate, and converting between them
Distance fields and volumes are two views of the same idea: one is the live formula, one is the frozen grid. Meshes round out the trio — solid surfaces you can sculpt and shade.
Distance Field → Volume — bake the formula onto a grid to render it as lit fog or a shaded surface, or to feed it into volume effects.
Volume → Distance Field — read the distance to where the volume crosses its surface, handing you back an exact, live formula.
Mesh → Distance Field — measure distance to a model's surface, so you can thicken it, shell it, or boolean it smoothly.
Distance Field / Volume → Mesh — extract a watertight surface from the field, turning blended, organic shape back into editable geometry.
In practice you rarely think about these as conversions — connect a sphere to a Volume node, or a mesh to an effect that wants a field, and DNA performs the automatic conversion for you. Just wire the nodes; the app sorts out the rest.
Bigger grids mean more detail but more memory. Volume resolution roughly doubles its cost in each direction, so a 512³ grid is eight times heavier than 256³. Start coarse, then raise resolution once the look is right.
See also
volume.render