Studio and Graph › Sculpt Tools
Masking and Selection
Paint a mask to limit where the brushes bite, then grow, shrink, blur or invert it. Nothing painted means the whole mesh is editable.
The polarity rule. The mask here is an isolate/include mask, not a ZBrush-style freeze mask. With nothing painted, the whole mesh is editable. As soon as you paint anything, only the painted area is editable, and a partially painted (feathered) area is affected partially. There is no separate "protect" paint - painting always defines what brushes CAN touch, never what they cannot.
The Weights input pin states the same contract in its own tooltip: "1 is full strength, 0 is frozen, in between feathers."
How to mask
| Action | Binding / UI |
|---|---|
| Enter/leave mask-paint mode | Mask: ON / Mask: OFF button in the Masking block, or M. Tooltip: "Toggle mask painting on/off (M)". The label is green when on, red when off. |
| Paint | With mask mode on, LMB-drag on the surface. A click that misses the mesh entirely is a true no-op. |
| Erase | Shift + LMB-drag. |
| Switch Brush / Marquee mode | Mode: Brush / Mode: Marquee button, or Shift+M. Tooltip: "Cycle selection mode (Brush / Marquee) (Shift+M)". Switching to Marquee also force-enables mask mode. |
| Marquee-select | Drag a rectangle in the viewport - it draws as a translucent blue fill with a 1px outline. Ctrl adds to the selection, Shift removes, no modifier replaces it. |
| Camera-facing filter for marquee | Facing: On / Facing: Off button. Tooltip: "When marquee-selecting, pick only camera-facing vertices (skip back faces behind the visible surface)." |
| Invert | Invert button, or Ctrl+I. Tooltip: "Invert the current vertex selection (Ctrl+I)". This is a graded invert (mask' = 1 - mask), so feathered edges survive. |
| Clear | Clear Mask button, or Alt+M. Tooltip: "Clear the entire vertex mask (CPU selection + GPU paint) and drop the on-mesh overlay. Also clears any rows selected in the Sections list. (Alt+M)". |
| Mask by sections | Click rows in the Sections list at the bottom of the Masking block. Columns are Section and Visible, each row has a visibility eye whose tooltip is "Toggle visibility of this section in the preview viewport. Hidden sections are excluded from brush ROI capture." A section the app cannot name renders as <unknown>. |
The mask overlay is not tied to mask-paint mode: it shows whenever paint mode is on, or whenever a mask already exists - so leaving mask mode to go sculpt does not hide the tint.
Filter operations
Five GPU operations plus Boundary select, all in the Masking block:
| Button | Tooltip | Default key |
|---|---|---|
| Blur | "Soften the mask edge (one-ring average, feathered)" - runs 2 iterations | Ctrl+B |
| Grow | "Expand the mask by one ring" | Ctrl+G |
| Shrink | "Contract the mask by one ring" | Ctrl+Shift+G |
| Sharpen | "Tighten the mask edge (unsharp)" | Ctrl+Shift+B |
| Cavity | "Mask by cavity: concave crevices become masked (replaces the current mask)" - strength 4 | Ctrl+K |
| Boundary | "Select every open-boundary vertex into the mask. Boundary topology is detected on the CPU; the result is uploaded to the GPU-resident mask like the other selection ops." | none |
Grow and Shrink can step by world distance instead of by vertex ring - see Grow Shrink By Distance below.
Masking settings
| Setting | Default | What it does |
|---|---|---|
| Wireframe Color | Blue | "Colour of the live mask-selection wireframe drawn over the mesh." Applies live. |
| Solid Mask Fill | on | "Render the masked area as a solid surface (the legacy "selection mesh") on top of the mesh, not just its wireframe. Always on while the wireframe overlay / wireframe view mode is active, where the mask wireframe would otherwise be hidden by the mesh wireframe." |
| Solid Mask Opacity | 0.8 (0.05-1.0) | "How opaque that solid mask surface is. Keep it low - the tint should read as a coloured wash over the surface, not as a flat patch that hides the shape." |
| Full Strength Mask | on | "Paint the mask at FULL strength (1.0) with a hard edge, ignoring the brush falloff - every vertex inside the brush is fully masked. Off: the falloff feathers the mask, and tools scale their effect by that gradient." |
| Selection Mode | Brush | "How vertices are added to the selection." Values: Brush, Marquee. |
| Ignore Boundary Vertices | off | "Skip vertices that lie on a mesh boundary." |
| Render Unselected | on | "Draw unselected vertices behind the selection." Turning this off isolates the mesh to the masked sections. |
| Hit Back Faces | off | "Allow brush hits on back-facing triangles." Also gates whether mask paint can soak through to the far side. |
| Enable Mask Selection | off | "Toggled on/off via the mask-paint UI (action row Mask ON/OFF button + the runtime details panel). When true the brush paints into the selection set instead of deforming geometry." |
| Marquee Front Facing Only | on | "When marquee-selecting, pick only vertices whose (welded) normal faces the camera, skipping back-facing verts behind the visible surface." |
| Grow Shrink By Distance | off | "Grow / Shrink offset the mask by a world DISTANCE instead of by one vertex ring. A ring step advances further through sparse geometry than dense geometry, so on an uneven mesh the mask shears out of shape; a distance step is the same everywhere. Both modes preserve a feathered edge - they translate the falloff, not flatten it." |
| Grow Shrink Distance | 1.0 (UI 0-25) | "How far Grow / Shrink move the mask edge, in world units." Shown only when Grow Shrink By Distance is on. |
The Weights pin seeds the mask
The Weights input on Sculpt Mesh is how you feed in a mask from elsewhere in the graph, rather than painting one by hand:
| Pin | Tooltip |
|---|---|
| Mesh (in) | "The mesh you want to sculpt on." |
| Rest Pose (in) | "The same mesh before you sculpted it. Delta is measured against this, and the Restore brush paints back toward it." |
| Weights (in) | "Where the brushes are allowed to bite: 1 is full strength, 0 is frozen, in between feathers. Leave it unconnected to sculpt the whole mesh." |
| Reference (in) | "The surface the Project brush pushes vertices onto. The other brushes ignore it." |
| Mesh (out) | "The sculpted mesh, once you press Accept." |
| Delta (out) | "How far each vertex moved from the Rest Pose. Feed it to Apply Deltas to put the same change on a different mesh." |
When you wire a weight map into Weights, its graded values are uploaded verbatim as the starting mask - so a wired weight map IS the starting mask, feathering included. It takes effect when you select the Sculpt Mesh node, not continuously, and if you also edit the mask by hand afterwards, your edit wins.