Tidal Volumes
Carve water away, contain water, and cut pixel-exact cross-sections.
Volumes control where water exists relative to a 3D region. Each volume lives on its own GameObject and either carves water out of its shape or contains water only inside it. They also drive v2.0's pixel-exact underwater cross-sections - aquarium walls, submarine windows, and pool cut-aways.
What volumes do
- Water is removed inside the volume.
- Use for submarine interiors, rooms below the waterline, dry docks, and moon pools.
- Water exists only within the volume.
- Use for aquariums, pools above ground, and tanks.
Creating a volume
Create volumes from the GameObject menu:
GameObject → Tidal 2 → Volume → Cube | Sphere | Cylinder | SDF (Mesh).
New volumes default to EXCLUDE, ClipVisual = None, a transform
scale of ×3, and an Affected Layer Mask set to the Water
layer. Cube, Sphere, and Cylinder are
analytic volumes; SDF (Mesh) is an
SDF volume.
Shared settings
| Setting | What it does |
|---|---|
| Flags | EXCLUDE carves water out of the volume (submarine interiors, rooms below the waterline, dry docks). INCLUDE makes water exist only inside the volume (aquariums, above-ground pools, tanks). |
| Feather | Softens and insets the clip boundary. The cross-section mask automatically accounts for the feather so cut faces stay aligned. |
| ClipVisual | What the volume does visually: None, full clipping, or Underwater Mask (the cross-section cut-away, see below). |
| Affected Layer Mask / Affected Bodies | Which bodies the volume applies to (by layer, by explicit list, or both). |
| Cross Section Scale | Per-volume fine-tune of the cross-section look. |
Dry cavities
When the camera sits inside an EXCLUDE volume's carved void below the waterline, that void stays dry: the underwater fog switches off (no fog pop), while the surrounding water shows through the cavity's cut faces. Combined with the Underwater Mask visual, this produces the submarine / underwater-room interior look.
Underwater Mask cross-sections
With ClipVisual = Underwater Mask, the water column behind the volume's below-water cut faces renders as if the camera were submerged, starting exactly at the face - an aquarium-glass view straight into the water. Since v2.0 the mask is pixel-exact:
- Analytic volumes resolve by a closed-form fullscreen ray-intersection - no proxy meshes.
- The cut face fits the water edge at any shape, scale, feather, or LOD, including while the volume moves.
- SDF volumes rasterize their renderer mesh for the same purpose.
- Maximum 8 analytic mask volumes on screen at once.
- Off-screen mask volumes are frustum-culled on the CPU and cost nothing.
- The pass is gated by the body's Volume Masks setting / renderer default; the editor warns on both the volume and the body when a mask can't render.
- Works from above water, from below, at partial submergence, and with the camera inside the volume.