Create and edit 3D models in Blockbench using MCP tools. Use when building geometry with cubes, creating meshes, placing spheres/cylinders, editing vertices, extruding faces, or organizing models with groups. Covers both cube-based Minecraft modeling and freeform mesh editing.

Blockbench Modeling Build 3D models using cubes and meshes in Blockbench. Plan the Shape and Target Before a new model or substantial geometry redesign, resolve the user's appearance/accuracy, performance, or balanced preference through [Blockbench use](../blockbench use/SKILL.md). Follow [appearance and performance planning](../blockbench use/references/appearance and performance.md) to set a working element/face budget and choose which details belong in geometry, UV tiles, or PBR. Prototype and count one repeated section before multiplying it; braces, infills, foot plates, and fasteners should not automatically become separate cubes. Spend faces on silhouette, parallax, and deformation. Delete faces no required view or pose reveals, since real time meshes need not be watertight. Let parts intersect instead of stitching edge loops around the joint, and float thin detail planes instead of cutting detail in. Keep geometry for recesses and openings whose depth must change as the camera moves. See [real time asset planning](../blockbench use/references/real time asset planning.md) sections 4–6 for per target budgets and face removal rules. Use [format and delivery guidance](../blockbench use/references/formats and delivery.md) when selecting a format or exporting. Block out the silhouette and proportions before UV layout and surface detail. Match polygon density to visible shape or deformation needs; automatic subdivision is not a quality step by itself. For articulated parts, create a hierarchy with pivots at joints and unique, consistent bone names. Group origins are pivots, not translations added to a cube's from / to coordinates. Place cube bounds in the model's rest coordinate space; the hierarchy applies rotations around those pivots. Mesh vertices are mesh local, as described below. Check overlapping surfaces for z fighting and preview moving parts for hidden gaps. See the official [modeling overview](https://blockbench.net/wiki/guides/blockbench overview tips/). When resizing or duplicating textured geometry at a different size, re evaluate the face UV spans rather than blindly retaining the source rectangle. Follow [UV scale and distortion guidance](../blockbench texturing/references/uv scale and distortion.md) for side/end proportions, final scale transforms, and shared material density. Correct mapping within the chosen geometry budget; additional cubes are not the default remedy for texture stretching. Available Tools Cube Tools Tool Purpose place cube Create cubes with position, size, texture modify cube Edit cube properties (position, rotation, UV, etc.) get cube uv / set cube uv Inspect/edit box or per face cube UVs; see texturing skill Mesh Tools Tool Purpose place mesh Create meshes with indexed faces; returns UUIDs and runtime geometry keys get mesh info Inspect mesh local positions, faces, normals, selection, textures, and optional UVs create sphere Create sphere mesh create cylinder Create cylinder mesh extrude mesh Extrude selected face regions; edge/vertex modes are unsupported subdivide mesh Subdivide selected triangles/quads into cuts + 1 segments per edge select mesh elements Select vertices/edges/faces move mesh vertices Move selected vertices delete mesh elements Remove geometry merge mesh vertices Weld nearby vertices create mesh face Create face from vertices knife tool Mesh point list cutting is unsupported through MCP knife cut cube Headless Knife tool for cubes: split at positions along one axis slice cubes to block grid Cut cubes at Bedrock block boundaries and regroup per block inspect block bounds Check cubes/groups against the 30×30×30 oversized block limits Element Tools Tool Purpose add group Create bone/group list outline View model hierarchy duplicate element Copy elements rename element Rename elements remove element Delete elements find elements by criteria Query elements by name pattern, type, parent, size select all of type Bulk select cubes, meshes, or groups filter by material Find elements referencing a texture Cube Modeling place cube supports untextured blockout in the current source plugin; use get capabilities: include tools=true to identify the loaded build. A new texture can be created after the silhouette is established. Supplying a texture or group requires a valid existing reference. Use returned UUIDs for later edits; the literal group="root" or add group 's parent="root" means outliner root. Name a real root bone rig root , or use its UUID, to avoid that reserved target. Place a Cube Place Multiple Cubes Modify Cube Cube with Texture Bedrock Poles, Cylinders, and Tubes For round primitives in Bedrock cube models, read [Bedrock primitive construction](references/bedrock primitives.md). It derives polygon side widths and shared pivot rotations for solid and hollow shapes, following the Shape Generator plugin's octagon and 16 sided constructions. Choose facets within the appearance/performance budget, distinguish flat to flat from corner diameter, and verify overlapping end faces and UV scale. create cylinder creates a mesh; use calculated place cube batches when the target requires cubes. Mesh Modeling Check get capabilities before creating meshes. Use a registered format with format.features.meshes=true , normally free (Generic Model). Create a Mesh and Retain Its IDs The JavaScript examples below are client orchestration pseudocode: call(name, args) invokes that MCP tool and checks for isError . For JSON results, it returns structuredContent or the decoded JSON text; for plain text results, it returns the text unchanged. It is not code for risky eval . Variables such as panel.uuid and panel.face keys[0] must be replaced with their returned values in actual tool arguments, never sent as literal strings. Input faces use zero based vertex indices . Returned vertex keys and face keys follow input order and hold the actual runtime keys. Later selection, face creation, and UV tools need those keys. A mesh name or UUID identifies the mesh, not its vertices or faces. Retain the UUID to avoid ambiguous names. After topology edits or undo/redo, inspect again before reusing component keys. Inspect Geometry and Read Every Page For primitives or existing meshes, obtain keys with get mesh info . Vertex items contain {key, position, selected} ; face items contain {key, vertices, normal, selected, texture} . Positions, bounds, and normals are mesh local , before origin, rotation, and parent transforms. Each list has its own next offset ; null means complete. The default limit is 100, maximum 500 per list. Finish paging before mutating geometry because keys are sorted and edits can invalidate offsets. Inspection is read only and does not select components. Create Sphere Create Cylinder Extrude Face For the unrotated, capped cylinder created above, select all cap triangles facing local +Y: Subdivide for Detail Move Vertices Continue from the panel creation example, before changing its topology: Merge Close Vertices Knife Cut The mesh Knife tool depends on interactive pointer state, so knife tool returns an unsupported operation error for point lists. For a scripted mesh cut, inspect with get mesh info , construct the intended replacement vertices/faces with place mesh , verify them, then replace the original geometry within the user's requested scope. Use Blockbench's interactive Knife tool when the user prefers to cut manually. Cubes can be cut headlessly. knife cut cube mirrors Blockbench's Knife on cubes: each cut plane is perpendicular to one axis, the original keeps the lower piece, new pieces get unique names ( pole 2 , pole 3 ), and face UVs are shared proportionally. One undo entry covers all cuts. Oversized Bedrock Blocks A Bedrock custom block's geometry must fit a 30×30×30 box whose center may sit at most 7 units from the block center, which Blockbench enforces as x/z within ±22 and y within 14…30 (Microsoft's page states the limit more loosely: https://learn.microsoft.com/minecraft/creator/documents/customblockoversized). Larger models must be divided into per block sections. 1. inspect block bounds reports model, group, and cube extents against those limits, the block cell each cube sits in, and the grid cut positions that would split it. 2. slice cubes to block grid cuts every cube where it crosses a block boundary (x/z boundaries at ±8, ±24, …; y at 0, 16, 32, …) and, by default, moves the pieces into one group per block cell ( bottom , top , right top front , top2 , …) pivoted at that block's origin. Cubes rotated about the other two axes are left uncut and listed in skipped rotated . 3. Export each cell group as its own block geometry, or slice manually with knife cut cube when the automatic grid is not what the model needs. Organization Create Group Hierarchy Add Cubes to Groups Duplicate Element View Hierarchy Selection & Filtering Query the model without loading the full outline. These tools are read only except select all of type . Find Elements by Criteria Combine any of: regex name match, substring match, type, parent group scope, cube size bounds, selection scope. Returns { count, truncated, matches: [{ uuid, name, type, parent }] } . Select All of Type Filter by Material Find every cube or mesh that references a specific texture. For cubes, the exact face keys are returned. Useful when refactoring textures: find all users before swapping or retiring a texture. Common Patterns Minecraft Character This example assumes a cube format with a bone rig and a 32 unit tall rest pose. It does not prescribe a player skin template. The cube bounds already include their location in the character; the group pivot does not reposition them. Smooth Organic Shape Only subdivide when the requested shape needs the extra vertices. Subdivision adds topology; it does not by itself smooth the silhouette. The predicate uses local Y, so 0 selects the upper half of this sphere even though its origin is at world Y=8. Use a predicate appropriate to the inspected geometry for other shapes. Tips Use list outline to see current model structure Use find elements by criteria for targeted queries instead of filtering list outline results client side Set group origins at joint/pivot points for animation Use faces=true for size based cube UVs; inspect and arrange the UVs before detailed painting Create bone hierarchy before adding geometry duplicate element with an offset creates a translated copy, not a mirrored shape or mirrored UV layout Mesh editing is more flexible but cubes are simpler for Minecraft style models For a substantial rework, a save checkpoint history marker can help recovery; inspect actual history entries before undo

blockbench-modeling