Modeling in Blender
Building meshes in Blender 5.x (5.2 LTS): Edit Mode selection, the core tools, the modifier stack, smooth shading after the 4.1 auto-smooth change, hard-surface vs organic workflows, sculpting basics, retopology, low-poly rules for games and the web, cleaning AI-generated meshes and precision modeling. Vocabulary (vertex, edge, face, normal, n-gon, topology, manifold) is in Core concepts; navigation and transforms are in Interface & navigation. Keys are Windows-style; on macOS read Ctrl as ⌘ (or ⌃) and Alt as ⌥.
Primitives & Edit Mode selection
Shift+A > Mesh adds a primitive at the 3D cursor: Plane, Cube, Circle, UV Sphere, Ico Sphere, Cylinder, Cone, Torus, Grid, Monkey. Set its size and segment count immediately in the Adjust Last Operation panel (bottom left, or F9); once you edit, that panel is gone. The default cube is 2 m on a side.
Tab enters Edit Mode. Select modes: 1 vertex, 2 edge, 3 face (Shift+1/2/3 combines modes).
| Select | Keys | Notes |
|---|---|---|
| Edge loop | Alt+click an edge | a ring of edges around the model; Shift+Alt+click adds |
| Edge ring | Ctrl+Alt+click | the parallel edges across a loop (where a loop cut would go) |
| Shortest path | Ctrl+click | from the active element to the clicked one; Shift+Ctrl fills a region |
| Linked (island) | L under the pointer / Ctrl+L from selection | everything connected; Delimit in F9 stops at seams, sharp edges or materials |
| Grow / shrink | Ctrl + numpad + / − | one ring outward / inward |
| Similar | Shift+G | same normal, area, length, material… |
| Checker deselect | Select > Checker Deselect | every other face, for panel patterns |
| Non-manifold (holes, loose edges) | Select > Select All by Trait > Non Manifold | find problems |
| Mirror selection | Shift+Ctrl+M | select the other side of a symmetric mesh |
With Emulate 3 Button Mouse (Alt modifier) loop select is a double-click and ring select is Ctrl + double-click. Hidden faces: H hides, Alt+H reveals, just as in Object Mode.
Core tools
| Tool | Keys / menu | What it does | Tips |
|---|---|---|---|
| Extrude | E | pulls new geometry out of the selection | E then Z locks the axis; canceling with RMB still leaves the new geometry on top of the old (fine before S, otherwise Ctrl+Z) |
| Extrude menu | Alt+E | along normals, individual faces, manifold | individual faces for panels on curved surfaces |
| Inset | I | a smaller face inside each selected face | press I again for individual insets; exact thickness in F9 |
| Bevel | Ctrl+B (edges), Shift+Ctrl+B (vertices) | chamfers or rounds edges | wheel = segments; P = profile; set exact width in F9 |
| Loop cut | Ctrl+R | adds edge loops across a ring | wheel = count, click, then slide (RMB centers it); E = even |
| Knife | K (Shift+K: selected only) | draw cuts across faces | Enter or Space confirms; C cuts through; X/Y/Z lock the angle |
| Knife Project | Mesh > Knife Project | cuts the outline of another object, as seen from the view | logos, windows in a wall |
| Make edge / face | F | connects 2 vertices or fills a selected border | repeat F to keep filling (better with the F2 extension) |
| Fill / Grid Fill | Alt+F / Face > Grid Fill | triangulated fill / quad grid fill of a hole | Grid Fill needs an even number of border edges |
| Bridge Edge Loops | Edge > Bridge Edge Loops | joins two open loops with faces | arm to torso, pipe segments; Number of Cuts in F9 |
| Connect vertex path | J | cuts an edge between selected vertices | clean alternative to the knife |
| Merge | M | At Center, At Cursor, Collapse, At First / Last, By Distance | By Distance welds duplicate vertices |
| Delete / dissolve | X / Ctrl+X | delete removes and leaves holes; dissolve removes and keeps the surface | Limited Dissolve cleans flat areas |
| Separate / join | P / Ctrl+J (Object Mode) | P > Selection, By Material, By Loose Parts | loose parts: split a mesh of merged parts into objects |
| Split / rip | Y / V | detach selection / tear vertices apart | |
| Spin | toolbar Spin tool | extrudes around the 3D cursor | lathe profiles: vases, wheels; Screw modifier is non-destructive |
| Subdivide | Edge > Subdivide (or right-click) | splits edges and faces | Number of Cuts in F9 |
| Mirror / symmetrize | Ctrl+M / Mesh > Symmetrize | flip selection / copy one half onto the other | Mirror modifier for live symmetry |
| Slide | G G (edge or vertex slide), Shift+V | moves along existing edges | keeps the shape while re-spacing loops |
| Shrink / fatten | Alt+S | moves along normals | thicken shells without a modifier |
| Crease | Shift+E | sharpens an edge under Subdivision Surface | 1 = sharp corner |
| Menus | Ctrl+V / Ctrl+E / Ctrl+F | vertex / edge / face menus | seams, sharp marks, triangulate, grid fill |
Modifier stack
Modifiers are non-destructive operations evaluated top to bottom (Properties > Modifiers tab, Add Modifier; Ctrl+A over a modifier applies it). Order matters: Mirror before Subdivision, Bevel before Weighted Normal, Triangulate near the end.
| Modifier | For | Key settings | Apply before export? |
|---|---|---|---|
| Mirror | symmetric models, one half edited | Clipping (keeps center vertices on the seam), Bisect, Mirror Object | exporter can apply it; apply by hand before UV-ing mirrored halves differently |
| Subdivision Surface | smooth high-res shape from a low cage (Ctrl+1…5 adds one) | Levels Viewport vs Render, crease support | apply at the level you want, or keep the low cage for games |
| Bevel | rounded edges without touching the mesh | Amount, Segments, Limit Method Angle (30°), Harden Normals | yes (exporter can); check the tri count |
| Solidify | thickness for planes (walls, cloth, leaves) | Thickness, Offset, Even Thickness | yes |
| Array | repeats: fences, stairs, chains | Count or Fit Length, Relative Offset, Merge, Object Offset (rotation) | yes, or export one piece and instance it in the engine |
| Boolean | cut holes or combine shapes with a cutter object | Difference / Union / Intersect; solver Exact (robust), Float (fast), Manifold (fastest, closed meshes only) | yes, then clean the n-gons it leaves |
| Decimate | fewer triangles (LODs, scans, AI meshes) | Collapse ratio, Un-Subdivide, Planar (angle) | yes; check UVs and silhouette |
| Weighted Normal | makes big flat faces shade flat on chamfered hard-surface models | Weighting Face Area, Keep Sharp | yes; custom normals export in glTF |
| Remesh | rebuild a uniform mesh | Voxel (size, adaptivity), Blocks, Smooth, Sharp | yes; usually followed by retopology or Decimate |
| Shrinkwrap | project one mesh onto another | Nearest Surface Point / Project / Target Normal Project, Offset | yes (retopology, decals) |
| Triangulate | control how quads split into triangles | Quad Method Beauty / Fixed, Keep Normals, Minimum Vertices | optional: glTF triangulates anyway; use it when the split matters (normal-map baking, GTA) |
| Weld | merge by distance, live | Distance, Mode All / Connected | yes |
| Smooth by Angle | auto smooth (added by Shade Auto Smooth) | Angle 30°, Ignore Sharpness | only with the exporter's Apply Modifiers on (off by default); without it the export is smooth everywhere. Pinned last in the stack |
Buttons on each modifier: show in Edit Mode, On Cage (edit the result directly), show in viewport and render. glTF's Data > Mesh > Apply Modifiers (off by default) exports the evaluated result without destroying the stack.
Shading: smooth, flat & auto smooth
Shading decides how normals are interpolated, not the geometry. Since 4.1 there is no Auto Smooth checkbox in Object Data; the choices are:
| Command (Object menu or right-click) | Result |
|---|---|
| Shade Flat | every face faceted |
| Shade Smooth | everything smooth; removes Smooth by Angle modifiers |
| Shade Auto Smooth | adds a Smooth by Angle modifier (a geometry-nodes asset, 30° default): edges sharper than the angle stay hard; live and adjustable |
| Shade Smooth by Angle (F3) | one-shot: tags sharp edges by angle, no modifier |
| Edge > Mark Sharp | force a hard edge; respected by Smooth by Angle unless Ignore Sharpness |
Low-poly faceted look: Shade Flat. Hard-surface: Shade Auto Smooth + bevels + Weighted Normal. Organic: Shade Smooth. Every hard edge splits vertices on export (the GPU needs one normal per vertex), so hard edges raise the vertex count; that is expected.
Hard-surface workflow
Hard-surface = manufactured objects: crates, weapons, vehicles, buildings.
blockout (primitives, real sizes)
→ cut and add: Boolean cutters, inset + extrude, loop cuts
→ edges: Bevel modifier (Angle) or bevel by hand for games
→ normals: Shade Auto Smooth + Weighted Normal
→ cleanup: apply Booleans, dissolve n-gons on curved parts, check tris- Keep Boolean cutters in a "cutters" collection, Viewport Display > Display As Wire or Bounds, disabled in renders; the Bool Tool extension adds one-key cutters.
- Real bevels catch light; even a 1–2 mm bevel reads better than a sharp edge. For games, one segment + Harden Normals is cheap.
- Big flat panels can be n-gons (they don't deform); keep edge flow tidy around holes that will be subdivided.
- Apply scale before Bevel and Solidify, or widths come out wrong.
Organic: subdivision & sculpting
Subdivision modeling: model a low cage in quads, add Subdivision Surface (Ctrl+2), shape with proportional editing (O) and slides. Hold edges tight with support loops (Ctrl+R near an edge) or crease (Shift+E). Avoid triangles and n-gons on curved, subdivided or deforming areas; they pinch. Poles (vertices with 3 or 5+ edges) are fine on flat areas, bad at bends.
Sculpt Mode (Sculpting workspace, or Ctrl+Tab pie) pushes a dense mesh with brushes. Brushes are assets in the asset shelf; defaults have keys:
| Key | Brush | Use |
|---|---|---|
| V | Draw | build up / carve (hold Ctrl to invert) |
| C / Shift+C | Clay Strips / Crease Polish | block forms / sharp creases |
| G | Grab | move big masses |
| K | Snake Hook | pull out horns, tentacles |
| I / P | Inflate / Pinch | puff up / tighten |
| S | Smooth (or hold Shift with any brush) | relax |
| Shift+T | Scrape / Fill | flatten |
| M | Mask (A: mask pie) | protect areas |
| Key | Control |
|---|---|
| F / Shift+F | brush radius / strength (drag, click) |
| Ctrl (hold) | invert the brush (carve instead of add) |
| X / Y / Z buttons in the header | mesh symmetry (off by default; turn X on for characters) |
| Topology method | How | Use |
|---|---|---|
| Voxel remesh | R sets voxel size, Ctrl+R remeshes | uniform density between sculpt passes; merges intersecting parts |
| Dyntopo (Dynamic Topology) | Sidebar > Tool > Dyntopo checkbox; R sets detail | adds detail only where you sculpt; slower on big meshes |
| Multiresolution modifier | Subdivide in the modifier, sculpt at any level | detail on top of a clean base mesh; bake to a normal map |
Watch how a simple object goes from primitive to modifiers to proportional editing.
Retopology
Retopology = building a clean, light mesh over a dense one (sculpt, scan, AI output) so it deforms, unwraps and runs fast. Details go back on as a baked normal map (Materials, UVs & texturing).
| Option | How | Good for |
|---|---|---|
| Quad remesh (QuadriFlow) | Object Data > Remesh > Quad > Quadriflow Remesh (target faces, Preserve Sharp, Use Mesh Symmetry) | automatic quads for props and static meshes |
| Voxel remesh | Object Data > Remesh > Voxel | cleaning before sculpting or printing; not final topology |
| Decimate | modifier or Mesh > Clean Up > Decimate Geometry | fast triangle reduction; triangles, uneven |
| Manual retopo | new mesh over the high-poly, snapped to its surface | characters and anything that bends |
| Paid add-ons | e.g. Quad Remesher (Exoside) | better automatic quads |
Manual setup:
- Add a Plane, Tab, delete to a single vertex or start from one face; name it
retopo. - Snapping on (Shift+Tab) with Snap Target Face Project (or Face Nearest); in the snap popover enable the options that let it snap to other objects.
- Or add a Shrinkwrap modifier (Target: the sculpt, Offset 1–2 mm) with On Cage and Edit Mode on.
- Viewport Overlays (Edit Mode) > Retopology shows your mesh over the sculpt without X-ray clutter.
- Build with the Poly Build tool (Ctrl-click adds, Shift-click deletes, drag an edge to extrude a quad), E and F (F2 extension), Mirror modifier with Clipping for symmetric models.
- Follow the forms: loops around eyes and mouth, rings along limbs, extra loops at joints.
Low-poly for games & web
Budgets depend on platform and camera distance; see Core concepts and the target pages (web, Godot, GTA V). Engines count triangles, and GPUs pay for vertices (after splits) and draw calls (objects × materials).
| Rule | Why |
|---|---|
| Turn on Overlays > Statistics | shows Objects, Vertices, Edges, Faces, Triangles for the selection |
| Spend triangles on the silhouette | interior detail goes in the normal map |
| Delete faces nobody sees | bottoms of props on the floor, backs against walls |
| Few materials per object (1–2) | each material is a separate draw call |
| Quads while modeling; n-gons only on flat, non-deforming faces | predictable triangulation and subdivision |
| Triangulate (modifier, Keep Normals) when the split matters | normal-map bakes must use the same triangulation as the engine |
| Hard edges and UV seams on the same edges | both split vertices; aligning them avoids paying twice |
| Consistent normals (Face Orientation overlay: red = back face) | flipped faces render black or invisible |
Separate LOD meshes: crate_LOD0, crate_LOD1 via Decimate | distant copies cost less |
| Apply scale, origin at the base | engines place and collide by origin |
Cleaning AI-generated & scanned meshes
AI generators (AI generation) and scans give dense, triangulated, sometimes broken meshes with baked-in textures.
| Step | Command | Fixes |
|---|---|---|
| 1 | Ctrl+A > All Transforms, check real size | wrong scale and rotation |
| 2 | Edit Mode, A, Mesh > Clean Up > Merge by Distance (or M > By Distance) | duplicate vertices, seams that split the surface |
| 3 | Mesh > Clean Up > Delete Loose, Degenerate Dissolve | floating vertices, zero-area faces |
| 4 | Shift+N (Mesh > Normals > Recalculate Outside) | flipped normals (check the Face Orientation overlay) |
| 5 | Select > Select All by Trait > Non Manifold | holes, internal faces; fill with F / Grid Fill or delete |
| 6 | Mesh > Clean Up > Limited Dissolve | millions of coplanar triangles on flat areas |
| 7 | Decimate modifier (Collapse, ratio 0.1–0.5) | triangle count; watch the texture (UVs survive Collapse, mostly) |
| 8 | Remesh (Voxel) then Quadriflow, or manual retopo | unusable topology; then rebake the texture onto new UVs |
| 9 | 3D Print Toolbox (N sidebar > 3D-Print) > Check All | non-manifold edges, intersections, thin walls, distorted faces |
Shading looks lumpy after decimating: Shade Auto Smooth, or Shade Flat for a faceted style.
Precision & measurement
| Need | How |
|---|---|
| Exact size | N sidebar > Item > Dimensions (Object Mode), then Ctrl+A > Scale |
| Exact move / extrude | type while transforming: E Z 0.25 Enter, G X -0.1 Enter; = enables units (25cm) |
| Exact vertex position | N sidebar > Item > Vertex / Median (Local or Global) |
| Edge lengths, angles, areas | Viewport Overlays (Edit Mode) > Measurement: Edge Length, Edge Angle, Face Area, Face Angle (set Global to include object scale) |
| Arbitrary distance | toolbar Measure tool (ruler); Ctrl snaps its ends |
| Snap corner to corner | Snap Target Vertex, Snap Base Closest |
| Grid-aligned blockouts | Snap Target Increment + Absolute Increment Snap, or Grid |
| Equal spacing | Array modifier with Relative Offset 1 (+ gap), or LoopTools > Space |
| Reference images | Shift+A > Image > Reference (or Mesh Plane for a textured plane) in front/side views |
Does this survive export?
| Blender feature | glTF / engines | Action |
|---|---|---|
| Quads and n-gons | triangulated on export | fine; triangulate yourself only when the split matters |
| Modifiers | evaluated if Apply Modifiers is on (off by default; Godot's .blend import uses the same exporter) | keep the stack; apply by hand for GTA (Sollumz) or special cases |
| Marked sharp edges, flat / smooth faces | exported as split normals (Normals option) | keep Normals on in the exporter |
| Smooth by Angle, Weighted Normal | modifiers: their normals export only with Apply Modifiers on | turn it on, or apply them first |
| Subdivision creases, Multires | not in the file; only the evaluated mesh | apply levels, or bake detail to a normal map |
| Boolean cutters | exported as meshes if visible | disable in render / hide, use Include > Visible or Renderable Objects |
| Loose edges / points | skipped unless Loose Edges / Loose Points are on | delete them |
| Curves, text, metaballs | not preserved | Object > Convert > Mesh first |
| Shape keys | morph targets | see Animation |
| Color attributes | exported when used by the material | see Materials, UVs & texturing |
| Geometry Nodes instances | experimental exporter option | realize instances (Realize Instances node) if in doubt |
Target specifics: Web / Three.js (Draco / Meshopt, triangle budgets),
Godot (-col, -colonly name suffixes for collision), GTA V
(Sollumz, LODs, collision meshes).
Recipes
Model a low-poly crate ready for a game
Use for any boxy prop: about 100–300 triangles, one material.
- Shift+A > Cube; N > Dimensions 1, 1, 1 m; Ctrl+A > Scale.
- Tab, 3 (face select), A, I then I again (individual) 0.08 m; E,
-0.03 Entersinks the panels. - Select the outer edges (Alt+click loops), Ctrl+B, 0.015 m, 1 segment.
- Tab out, Shade Auto Smooth; add Weighted Normal (Keep Sharp) for clean flat faces.
- Delete the bottom face if it always sits on the floor.
- Overlays > Statistics: check triangles; origin at the bottom center
(recipe); name it
crate. - UVs and texture: Materials, UVs & texturing.
Cut a round hole with a Boolean
Use for hard-surface panels, windows, vents.
- Add a Cylinder (Vertices 24–32 in F9) through the panel; name it
cut_hole. - Panel: Add Modifier > Generate > Boolean, Difference, Object
cut_hole, solver Exact. - Cutter: Object > Viewport Display > Display As Wire; disable in renders.
- Optional Bevel modifier (Limit Method Angle) below the Boolean for rounded rims.
- Before export: apply the modifiers, then Limited Dissolve and J to connect the n-gons around the hole if the part will be subdivided.
Mirror-model a symmetric object
Use for characters, vehicles, furniture.
- Model around X = 0; delete the −X half in Edit Mode.
- Add Mirror (Axis X, Clipping on) so center vertices can't cross the seam.
- Model one side; the other updates live.
- Apply the Mirror before UV-unwrapping if the two halves need different texture areas; otherwise keep it (mirrored UVs save texture space).
Clean up an AI-generated GLB
Use after File > Import > glTF 2.0 on a model from an AI generator.
- Ctrl+A > All Transforms; scale to real size against a reference cube.
- Edit Mode, A, Merge by Distance (0.0001 m), Shift+N.
- Mesh > Clean Up > Delete Loose, Degenerate Dissolve.
- Decimate modifier Collapse to the budget (e.g. ratio 0.2), then apply.
- Shade Auto Smooth; 3D Print Toolbox > Check All for leftovers.
- If the texture is baked and UVs are chaotic, keep the UVs; if you retopologized, rebake onto new UVs (baking).
Retopologize a sculpt with QuadriFlow
Use for static props from sculpts or scans.
- Duplicate the sculpt (Shift+D, RMB); hide the original.
- Object Data > Remesh > Voxel with a size that keeps the silhouette.
- Remesh > Quad > Quadriflow Remesh: Mode Faces, target 2,000–5,000, Preserve Sharp.
- Unwrap, then bake normals from the original (selected to active).
Make LODs with Decimate
Use when an engine shows the asset at several distances.
- Finish
LOD0; Shift+D a copy namedname_LOD1. - Decimate Collapse ratio 0.5 on LOD1, 0.25 on
LOD2; Planar mode for flat hard-surface parts. - Check the silhouette from the distance it will be seen; apply.
- Keep UVs shared so LODs reuse one texture set.
References
- Blender Manual: Mesh selecting (opens in a new tab): loops, linked, by trait
- Blender Manual: Mesh editing tools (opens in a new tab): extrude, inset, bevel, loop cut, knife, bridge, merge, clean up
- Blender Manual: Modifiers (opens in a new tab): every modifier and its options, including Boolean (opens in a new tab) and Smooth by Angle (opens in a new tab)
- Blender Manual: Object shading (opens in a new tab): Shade Smooth, Auto Smooth, Flat
- Blender Manual: Remeshing and retopology (opens in a new tab): Voxel, Quad (QuadriFlow), manual retopology
- Blender Manual: Sculpting (opens in a new tab): brushes, Dyntopo (opens in a new tab), Remesh (opens in a new tab)
- Blender Manual: Viewport overlays (opens in a new tab): statistics, face orientation, measurement, retopology
- Blender Manual: glTF 2.0 (opens in a new tab): what the exporter does to meshes
- 3D Print Toolbox (opens in a new tab), LoopTools (opens in a new tab), F2 (opens in a new tab), Bool Tool (opens in a new tab): free extensions used above
- Blender Guru: Donut tutorial (2026) (opens in a new tab): the classic first project