Mesh Editing

Reshape any mesh by hand: drag its vertices, slide its edges, extrude and bevel its faces, fill holes, give a surface thickness, cut it with a knife, mirror one half onto the other — or combine two meshes with a Boolean. Every edit replicates to your peers and every step is undoable.

Entering and leaving

Select a mesh, then either press Tab or right-click it ▸ Edit mesh. The Edit Mesh toolbox opens — a floating tool palette you can drag anywhere and resize by its right edge.

Action	How
Enter	Tab, or right-click ▸ Edit mesh
Done	Esc or the ✓ button — keeps your work
Cancel	the ✕ button — reverts everything since the session opened (it asks first)
Undo / redo one step	Ctrl+Z / Y, or the ↶ ↷ buttons in the toolbox header

Cancel is not a bigger undo

↶ steps back one operation. ✕ throws the whole session away and puts the mesh back as you found it — which is why it is marked as the destructive one and asks before it acts.

While you edit, the object is locked for your peers, and the usual selection outline steps out of the way so it can't hide your work.

The toolbox

Part	What it holds
Tabs	Vertices / Edges / Faces — they stay pinned while the rest of the panel scrolls
Header	Undo, redo, the key cheat sheet (?), Done and Cancel
Tools & operations	The grid for the current mode, with the selected tool's parameters right below it
Sections	Gizmo & pivot, Cleanup, Symmetry, Display (and Collider while you edit a custom collider) — collapsible, and available from every element mode

Drag the header to move it, drag its right edge to change the width (the tool grid reflows), and double-click the grip to reset it. On a phone it becomes a bottom sheet you can drag taller or shorter instead of a floating window.

One undo step for the whole session

Individual operations undo one at a time while you work. When you press Done, the whole session collapses into a single undo entry — so Ctrl+Z afterwards puts the mesh back the way it was before you started, not one extrude at a time.

The three element modes

A mesh can be edited by vertex, edge or face. Switch with the tabs at the top of the toolbox, or press Tab to cycle forwards and Shift+Tab backwards.

Each mode remembers its own selection, so you can hop between them without losing your pick.

1 / 2 / 3 stay Move / Rotate / Scale

Those keys mean the same thing inside a mesh session as everywhere else in the app — they switch the gizmo, which is what you reach for mid-edit. The element modes live on Tab.

Selecting

• Click an element to select it; Ctrl+click adds to the selection.
• Shift+drag or Ctrl+drag draws a box — every vertex, edge or face inside it joins the selection. Works in all three element modes, and a box always takes whole faces (never half a quad). An empty box changes nothing, so a stray drag cannot wipe your work.
• Selection commands appear as words in the Select row — they change what is picked, never the geometry:

Command	Modes	What it picks
Loop (L)	all	Faces: the quad ring through this face — press again for the perpendicular one. Edges: the edge chain, end to end.
Ring	edges	The parallel rungs a face loop crosses — the other half of the standard pair.
Grow / Shrink (Ctrl++ / -)	faces	Add the neighbouring ring / drop the border ring.
All (Ctrl+A)	all	Every element of the mesh.
Invert (Ctrl+I)	all	Swap picked and unpicked.
Linked	faces	The whole connected island this face belongs to.
None	vertices	Deselect everything.

Selections are undoable too — Ctrl+Z steps back through your picks without touching the geometry, and a selection step can never push a real edit off the undo stack.

Pick granularity (faces)

In face mode, a granularity switch decides how much one click picks up:

Setting	Picks
Quad (default)	The quad under the cursor — the two triangles that form it (a 3-sided face picks alone).
Face	The whole coplanar face.
Tri	The single triangle under the cursor.
Shell	The connected island under the cursor — on a one-piece mesh that is the whole object.
Object	Every triangle, including islands not connected to each other.

Tip

Quad is what you want almost always. A model is made of triangles underneath, but you think in quads — and so do the loop tools.

Apply, then adjust

Most operations run the moment you press them and then let you tune the result: the options pane becomes an Adjusting panel, and changing a value re-runs the operation from the original shape rather than piling a second one on top. Nudge the width until it looks right, then carry on — or press ✕ to take the whole thing back.

• If an operation's preconditions are met (Bridge with two matching pieces selected, Bevel with a bordered selection), pressing it applies immediately.
• If they are not, nothing happens to your mesh and the toolbox says why, with an Apply button once you have fixed it.
• It is one undo step either way, however long you spend adjusting.

Tools and operations

The face tab splits its grid in two. Tools are armed — they change what a viewport click does, and stay armed until you pick another. Operations act on the selection you already have, once.

Icons are for tools; commands that act immediately read as words. Whichever tool you select, its parameters appear right underneath it.

Tool	Key	What it does
Extrude	E	Pull the face out along its normal, stitching the walls behind it.
Inset	I	Shrink a copy inside a stitched ring — the cap ends up selected, ready for the next step.
Move	G	Seat the transform gizmo on the selection (the default).
Subdivide	S	Split the selection into a finer grid, 2×2 per quad.
Bridge	B	Build a tunnel between two selected pieces.
Loop cut	C	Insert edge loops across the ring your selection lies on (the cuts field sets how many).
Knife	K	Cut across the mesh on screen, in a straight line or a polyline — see below.
Flip normals	F	Reverse the winding, for a face that renders inside-out.
Duplicate		Copy the selected faces in place. They start exactly on top of the originals — drag them off with the gizmo.
Solidify		Give the selected surface thickness — see below.
Separate		Move the selected faces into a new object of their own, in the same place, with its own copy of the material. One Ctrl+Z puts them back.
Delete	X	Remove the selection.

Move is the default, deliberately

With auto-apply on, a plain click commits whatever is armed — so the armed tool starts as Move. Clicking a face to look at it should never extrude it.

Tool parameters

Tool	Parameters
Extrude	distance, and individual — extrude each face along its own normal instead of the selection's average
Inset	amount, plus a depth that raises or lowers the cap as it goes in
Bevel	width (in world units), segments, profile — and the direction, in or out
Loop cut	cuts, position along the ring, and which of the two directions to run — Along or Across
Bridge	cuts across the tunnel, twist to rotate one end against the other, and invert faces if the walls end up the wrong way round
Subdivide	levels — each one splits every quad 2×2 again
Solidify	thickness, in world units

Knife

Pick Knife, click one end of the cut and then the other. A dashed band follows your cursor between the two clicks so you can see where the blade will land; every face the line crosses is split. Esc drops a cut in progress without leaving the session.

The cut is a line on screen, so it slices straight through the model from your point of view — every layer under the line, front and back — and the result is always watertight. Orbit first to line up the angle you want.

Polyline cuts

Since 1.28 the knife cuts along a polyline, not only a straight line:

• Click where the cut starts.
• Shift+click places each corner (so does Ctrl+click, or a tap with the touch Multi-select button on). Corners you place on the mesh become real vertices, and the cut runs along mesh edges between them.
• A plain click on the last point ends the cut. Enter ends it at the last corner you placed.
• Backspace takes the last corner back; Esc drops the whole cut.
• While a cut is pending, the toolbox's Knife options show how many points you have placed, with Back and Cut buttons — the way to finish a cut on a touch screen.

A point within a few pixels of a corner of the face under it snaps onto that corner, and one within a pixel or two of an edge snaps onto the edge, so a cut does not leave needle-thin triangles. The whole polyline is one undo step, and your peers see the cut as it is committed.

Changed in 1.28

A two-click cut that ends inside the mesh now ends exactly where you clicked. Before, it ran on to the far corner of that triangle.

Solidify

Solidify gives the selected surface thickness: a copy behind it plus a rim joining the two. A positive thickness goes into the surface, a negative one grows outward. It works on an open surface or on a whole piece — a closed box becomes hollow. A patch of a closed mesh is refused: select the whole piece (Shell) or delete a face first.

Solidify uses averaged vertex normals, so sharp corners get slightly thinner walls.

Bridge

Select two separate pieces and press Bridge. Their boundaries have to have the same number of edges — the toolbox prints both counts next to the selection so you can check. Bridging two faces of one solid punches a hole through it; bridging two separate shells builds a tube between them, and the walls are wound correctly either way.

Edge tools

Tool	Key	What it does
Move		Seat the gizmo on the selected edges (X runs along the edge, Z out of the surface). The welded neighbours stretch with it.
Loop	L	Select the whole edge loop through this edge.
Slide		Move the selected edges along the faces on either side, keeping the shape — see below.
Fill	F	Close the hole the selected border edges go around with one new face — see below.
Bevel		Replace the edge with a chamfer strip (width, segments and profile below).
Extrude		Pull a border edge out into a new strip of faces. A chain of edges extrudes as one piece; interior edges have nothing to extrude into, so they are refused.
Subdivide		Split every face along the selected edge at its midpoint — both sides split at the same point, so no crack appears.
Dissolve		Remove the edge and merge the two faces it joined.
Delete		Remove every face touching the selected edges.

Slide edges

Pick a whole line first (Select ▸ Loop), then press Slide. The options pane shows factor: 0 is where the edges are now, +1 and −1 are all the way onto the neighbouring line on either side. Scrub it and watch the edges move; ✕ Revert undoes. A vertex with no single edge to run along (a box corner) stays put — the toast says how many.

Fill a hole

Select a border edge and press Fill (F): the hole it goes around is closed with one new face. One edge of the rim is enough to fill the whole hole. The cap is wound to match the faces around it. A flat, convex hole becomes a clean polygon; any other outline is fanned from its centre. Fill closes one rim at a time.

Mitered corners

Since 1.24 an end where four or more faces meet is bevelled with a mitered corner — a small cap joining the chamfer to every face there — instead of being refused. (Before, each end needed exactly three faces.)

Vertex tools

Tool	Key	What it does
Weld	W	Merge the selected vertices into one, at their centroid.
Create face		Build a face from 3 or 4 selected vertices.
Connect	J	Select two corners of the same face (Ctrl+click adds the second): the face is cut in two along the line between them. The two must not already share an edge.
Dissolve		Remove each selected vertex and merge the faces around it into one. A vertex in the middle of an edge just leaves that edge. Unlike Delete, the surface stays closed.
Bevel		Cut the corner off every selected vertex and cap it. Works on any number of vertices. Since 1.24 it has segments (1 – 8): more segments round the corner off, and profile sets how far it bulges (0 is a flat, subdivided cap).
Smooth		Relax the selected vertices toward their neighbours — factor sets how far each pass moves them, iterations how many passes.
Slide		Constrain the drag to one of this vertex's own edges. Adjusts a profile without pulling the vertex off the surface. A marker shows where it will land, and the clamp toggle decides whether it may run past the edge's end.
Delete		Remove every face touching the selected vertices.
Deselect		Clear the selection.

Vertices are drawn as dots sized in screen space, so they stay clickable whether you're zoomed into a cube or out of a whole terrain. The dot size slider multiplies that size, and turning the adaptive toggle off gives you a fixed world size instead.

Bevel options

Bevel works in all three modes and shares one set of options:

Option	What it does
Width	How far the chamfer reaches, in world units — the same 0.1 means the same size on a small prop and a large wall. Clamped per edge, so two bevels can never cross.
Segments	More segments = a rounder edge.
Profile	0 is a flat chamfer, positive domes the cap out, negative dishes it in.
Direction	Whether the chamfer eats in to the shape or grows out of it.

Tool values — the slide factor, the solidify thickness, the bevel segments — are remembered for the session, like the other tool options.

Boolean

Combine two meshes into one. Select exactly two meshes (Ctrl+click), then right-click the first one ▸ Boolean:

Operation	Result
Union	merge them into one solid
Subtract	cut the second out of the first
Intersect	keep only the overlap
Subtract, keep the cutter	as Subtract, but the second object stays

The first object takes the result and the second is removed (except in the keep the cutter variant). One Ctrl+Z restores both. Like every mesh edit, it is one undo step and reaches everyone in the session.

Limits

• The result uses the first object's first material.
• The inputs should be closed meshes: a mesh with holes gives a result with holes (the toast counts them).
• Very large results are refused by the usual size limit.

Proportional editing

Switch Proportional on and moving one element drags its neighbourhood along, fading off with distance — smooth bulges and dips instead of a single crease. It works in all three modes: vertices, edges and faces.

A ring on the model shows how far the influence reaches. Roll the wheel while dragging to resize it and watch the shape respond; the ring always faces you, so it stays readable from any angle.

It works for rotate and scale as well as move. The falloff blends the turn and the scale toward doing nothing as it fades out, so a rotation twists the surrounding surface instead of leaving it behind: a vertex halfway through the falloff turns halfway, which is what makes a straight edge through the radius come out as a spiral.

Your peers see the whole neighbourhood, not just the vertices you had selected. A proportional drag lands on every other screen in one step, when you let go — the bulge and the crease arrive together, as a single geometry change that undoes as one. During the drag, peers see what they always saw: the live preview if the mesh is under the streaming limit, and otherwise the result at the end. (The commit obeys the same size limits as any other topology change; past them the drag stands.)

Pivot and gizmo

The Gizmo & pivot section decides what the gizmo turns around:

• With several elements selected, transforms happen about the centre of the selection — rotate a whole patch and it turns as one piece.
• Place the pivot yourself by dragging the gizmo: the mesh stays put and only the pivot moves, so the next rotation or scale happens exactly where you want it.
• The gizmo's orientation (local or world) and whether it is shown at all are session-wide, and apply to every element mode.

The Pivot row's commands are Set here (the centre of the current selection), Pick… (click a point on the mesh; a nearby vertex wins, Esc cancels), Move (drag the gizmo, the mesh stays put) and Clear (back to the selection's own centre). The line under them always says which one is in force.

Slide stands down while a pivot is placed

Slide measures along the vertex's own edges from the gizmo, and a placed pivot has moved the gizmo off the vertex — so with one in place slide would do nothing. It now says so instead of going quiet: Vertex slide is off while a custom pivot is placed — the slide measures from the gizmo, and the pivot moved it off the vertex. Reset the pivot to slide. Press Clear in the Pivot row and slide comes back.

Clean-up

The Cleanup and Symmetry sections act on the whole object, not on your selection (Cleanup's commands are icon buttons — hover one for its name):

Command	What it does
Recalculate normals	Rewind every face to point outward — the cure for patches that render dark or inside-out.
Merge by distance	Collapse vertices closer than the given distance into one and drop the faces that go degenerate.
Smooth / Flat	Switch the mesh between smooth and faceted shading.
Triangulate	Break every face down into plain triangles.
Tris to quads	Pair triangles back up into quads — the loop tools work in quads, so this is how you make an imported triangle soup workable again.
Symmetrize	Keep one half and replace the other with its mirror image, across an object-local X / Y / Z axis through the object's origin. Pick which half to keep.

Model half of it

Symmetrize is a one-shot: shape the left side however you like, then mirror it. Faces that straddle the plane are cut cleanly on it, so the two halves join watertight.

Live symmetry

Since 1.28 the Symmetry section has a live symmetry switch. While it is on, every edit you make is mirrored across the chosen axis — the same X / Y / Z buttons as Symmetrize — from the side you edited:

• Extrude a face on the left and the right gets the same extrusion.
• In Vertices mode, dragging a vertex moves its mirror twin with it, live. A vertex on the mirror plane slides along the plane and never leaves it, so the seam stays closed.
• The side your edit changed wins; keep + / − only decides when the edit sits on the plane itself.
• The edit and its mirror are one undo step.

Turning it on does not change the mesh. If the mesh is not symmetric yet, press Symmetrize first — a vertex with no twin moves alone.

• Only your own edits are mirrored, and only while the switch is on. Undo, redo, Cancel and edits that arrive from peers are applied exactly as they were made.
• The switch is yours alone and is not saved: it is off again the next time you open the app. Peers get the mirrored geometry like any other edit.

Limits

• Face and edge gizmo drags are mirrored when you let go, not continuously while you drag.
• There is no live symmetry switch in VR yet. Edits you make in the headset are mirrored if the switch was turned on at the desktop.

Display

Toggle	What it does
Wireframe	Show the edit wireframe overlay (on by default). It draws the quad structure.
Show triangulation	Draw the raw triangles instead — the diagonals inside a quad are an artifact of triangulation, not edges of your model.
Selection outline	Bring the object outline back while editing (off by default).
Shortcuts	Turn the single-key shortcuts off, if they get in the way.
?	Open the key cheat sheet as its own little window you can park beside the viewport.

The overlay colours — wireframe, selection outline and the edit overlay — are yours to set in Settings ▸ Scene ▸ Wireframe & outline (Wireframe color, Selection outline color, Edit Mesh wireframe — Auto by default — and Reset line colors); the edit overlay defaults to picking a colour that contrasts with the material you are editing. Since 1.26 it re-tints the moment the object's colour changes, so faces and vertices never disappear into a new material colour.

Snapping while you edit

Element snapping applies to the mesh gizmo too — switch on the Vertex target and a dragged vertex bites onto another one, which is how you close a seam by hand without nudging.

Your mesh remembers its faces

Older versions worked out what a "face" was every time you clicked, by looking for triangles lying flat against each other. That guess falls apart as soon as you edit: rotate an extruded band a few degrees and its wall quads twist just enough to look like real creases, at which point the loop tools quietly stop working.

The face structure is stored with the mesh now. Operations describe the faces they create, so quads survive being rotated, subdivided and bridged, the loop tools keep working after any edit, and a face can have more than four corners — dissolving an edge leaves one real n-gon rather than a fan of triangles.

Note

One exception: an autosave snapshot is stored as GLTF, which cannot carry the face structure, so a restored autosave falls back to deriving it. Saved .tpscene files and sessions keep it.

Converting to a mesh

Right-click a group or a multi-selection ▸ Convert to mesh merges it into a single editable mesh, materials and all, as one undo step. Use it when you've assembled a shape from primitives and want to treat it as one piece.

The materials survive as slots on the merged mesh — see UV & Textures for assigning faces between them.

Sculpting

For organic shaping there's a brush instead: right-click a mesh ▸ Sculpt mesh (or Sculpt terrain on terrain) — raise, lower, smooth and flatten with a round brush. See Terrain & Sculpting.

Keyboard reference

The same list lives behind the ? button in the toolbox.

Keys	Action
Tab / Shift+Tab	Next / previous element mode (Vertices → Edges → Faces)
1 / 2 / 3	Gizmo: Move / Rotate / Scale
Ctrl+A	Select all
Ctrl+I	Invert the selection
Ctrl+Z / Y	Undo / redo one step inside the session
Tab (outside a session)	Enter Edit Mesh on the selected object
Esc	Done — leave the session
E / I / G	Faces: arm Extrude / Inset / Move
S / C	Faces: Subdivide / Loop cut
B / F / X	Faces: Bridge / Flip normals / Delete
F	Edges: Fill the hole
K	Faces: Knife
Shift+click / Enter / Backspace	Knife: place a corner / end the cut at the last corner / take the last corner back
L	Loop select (faces: again = perpendicular)
Ctrl++ / -	Faces: grow / shrink the selection
W	Vertices: weld the selected vertices
J	Vertices: connect two corners of a face

These keys can be rebound in the Mesh edit group of Settings ▸ Shortcuts. Some rows serve two modes, so rebinding one moves both: L is Loop in every mode, and F is Flip normals in Faces and Fill in Edges. J (Connect) has its own row.

In VR

Mesh editing works in VR too: the radial menu's Selected ▸ Edit mesh covers face select, extrude, inset, move and stretch, with the amount adjusted live by moving your controller. See the VR Guide.

Collaboration

• Editing an object locks it — your peers can see it but not edit it at the same time.
• Live gestures stream a preview to peers several times a second; the final shape is committed when you let go.
• Separate keeps the new object's face grouping (quads and n-gons) for everyone in the session, but a peer who joins later re-derives it — the same rule as for every edited mesh.
• A topology change travels as a full geometry snapshot. That has a ceiling, but a generous one — roughly half a million vertices, which is about thirty times what earlier versions allowed.

How big a model can you edit?

Three separate limits, and they are different questions:

Limit	What it governs
Commit (~500k vertices)	The finished edit that replicates and lands in undo.
Live preview (~15k vertices)	What streams to peers during a gesture. Above it your edit still works and still replicates — peers just see the result when you let go instead of watching it move.
Edit Mesh entry (2500 triangles)	How dense a mesh may be before the session refuses to open, so the interaction stays responsive. Raise it in Settings ▸ VR if your machine can take it.

All three come from measurement rather than caution: the numbers are what the wire, the frame budget and memory actually stood up to.