Volume Render
Create and manipulate 3D volumetric data.
What it does
Volume Render turns a shape, Distance Field, image, video capture, or another Volume into volumetric fog, cloud, or smoke and ray-marches it in the viewport. Multiple sources combine.
A shape becomes a soft puff of fog around its surface. An image is extruded into a thin depth-tapered slab. A captured frame stack becomes one depth slice per frame, a clip as a solid block of volume. Display Mode switches between soft volumetric fog and a lit solid surface for shapes and liquids. Scattering, Absorption, Phase, and the lighting controls shape how light moves through the medium. A Volume Material node wired into Material sets colour, scattering, and glow in one place instead.
When to use it
Fog, smoke, clouds or haze around a shape or Distance Field.
A flat image as a soft 3D slab, or a captured clip as a block of volumetric depth.
A solid-looking cloud, liquid or blob rendered as a lit surface rather than soft fog: Display Mode set to Surface.
Glowing fire or embers: Emission paired with a density-driven colour gradient.
| Parameter | Type | Default | What it does |
|---|---|---|---|
sources | Any | List | Geometry, SDF, Image, frame-stack (Capture), or Volume sources to render as volumetric fog/clouds |
fill | Color or Color Field or Scalar Field or Vector Field | — | — |
fill_channel | String | "" | For a multi-channel field fill (a captured record): which named Color channel to use. |
material_in | Implicit Render Settings | — | — |
display_mode | String | "Volumetric" | Volumetric: fog / cloud / smoke (default). Surface: lit solid — sphere-traces the SDF isosurface into the deferred renderer. One of: Volumetric, Surface. |
shade_smooth | Boolean | true | Smooth the sphere-traced surface normals (hides SDF voxel facets). Surface mode only. |
edge_falloff | Number | 0.500 | Edge falloff when extruding (0 = sharp, 1 = soft) |
volume_depth | Number | 0 | World-space depth of the volume (0 = auto). Sets how deep a raster or frame-stack source is extruded along Z. |
frame_channel_mode | String | "Color" | Frame stack → Volume: Color (keep RGB) or Luminance (grayscale density). Frame index becomes Z depth. One of: Color, Luminance. |
mesh_mode | String | "SDF" | SDF: smooth signed-distance field (surface render, collisions). Density: 0..1 occupancy grid you can blur (fog, reaction-diffusion). Mechanism is picked by the source — mesh voxelizes, points splat. One of: SDF, Density. |
point_radius | Number | 1 | Default radius for point splatting (overridden by per-point pscale attribute) |
kernel_type | String | "Gaussian" | Density falloff shape: Gaussian (smooth), Linear (cone), Constant (hard sphere). One of: Gaussian, Linear, Constant. |
smoothness | Number | 0 | Smooth blending radius when combining multiple geometry sources |
fog_distance | Number | 50 | Distance beyond surface where fog is visible (affects density falloff) |
detail_strength | Number | 0.350 | Wispy edge detail (smoke/cloud turbulence). 0 = off. Ignored for image/video volumes. |
emission_intensity | Number | 0 | Self-emission strength — hot regions glow. Pair with a density→blackbody gradient for fire. 0 = off. |
voxel_resolution | Number | 64 | Voxel grid resolution (higher = more detail, slower) |
voxel_padding | Number | 0.100 | Padding around mesh bounds as fraction of size |
voxel_fill_interior | Boolean | true | Fill interior of mesh (requires watertight mesh for correct results) |
voxel_tessellation | String | "Medium" | Tessellation detail for primitives: Low (8 segments), Medium (16), High (32), Ultra (64). One of: Low, Medium, High, Ultra. |
sdf_resolution | Number | 128 | SDF grid resolution (higher = more accurate distance field, less voxel cell aliasing) |
sdf_max_distance | Number | 10 | Maximum distance from surface to compute (affects fog extent) |
resolution | Number | 128 | Volume resolution (XY detail). Higher = sharper image/camera volumes; the bake auto-caps total voxels to stay within the GPU memory budget. |
bounds_size | Number | 100 | World-space size of the volume bounds (used for non-mesh sources; mesh sources derive bounds from the mesh AABB) |
scattering | Number | 0.500 | Scattering: 0 = no scattering, 1 = dense fog |
absorption | Number | 0.100 | Absorption: 0 = transparent, 1 = opaque smoke |
phase | Number | 0.300 | Phase: -1 = back scatter, 0 = isotropic, 1 = forward scatter |
ambient | Number | 0.200 | Ambient: minimum brightness in shadowed areas |
alpha | Number | 0.500 | Volume opacity in viewport |
strength | Number | 1 | Effect strength / wet-dry (0 = no effect, 1 = full). Editable, wirable, keyframable. |
Gotchas
A shape or Distance Field source that looks like it has vanished points at Fog Distance and Display Mode. Volumetric mode relies on Fog Distance to give the surface visible thickness; Surface mode sphere-traces the isosurface directly and ignores it.
Volume Depth defaults to 0 (auto): a single image keeps a thin tapered slab, while a frame stack spreads one world unit of depth per frame. Raise it to pin an exact Z thickness for either source.
A Volume Material node connected to Material overrides the node's own Scattering, Absorption, Phase, Ambient, and Alpha values, and the Fill input is ignored. Author all appearance on the Volume Material node upstream.
Detail (turbulence) and Emission affect shape and Distance Field volumes only. Image and video-capture volumes stay smooth.
Worked example
Add a Volume Render and wire a shape (or a Distance Field) into Sources.
Leave Display Mode on Volumetric for soft fog, or switch to Surface for a lit solid look.
Raise Detail for wispy turbulent edges, and raise Emission with a density-driven colour gradient on Fill for glowing fire or embers.
For full material control, wire a Volume Material node into Material instead of tuning Scattering/Absorption/Phase directly.