{ "$schema": "https://json-schema.org/draft/2020-12/schema", "$id": "https://www.truzme.com/schemas/project-code/v1.json", "title": "Truzme Project code", "description": "A 2D truss model for Truzme (truzme.com). Every number is in the units declared in `units`, and y increases upward. Entities reference each other by integer id: every `from`, `to`, `node`, `section` and `material` must match the id of an entry in the same document, and ids must be unique within each list. When Truzme applies a document, it replaces the model: an id that already exists updates that entity, a new id creates one, and anything left out is removed — except `dimensions`, where leaving the key out keeps the existing dimension lines. Display settings and background images aren't part of the document and are kept.", "type": "object", "additionalProperties": false, "required": ["units", "nodes", "members", "supports", "nodalLoads", "materials", "sections"], "properties": { "units": { "description": "The units every number in this document is written in. Numbers are converted from these units when the document is applied.", "type": "object", "additionalProperties": false, "required": ["length", "sectionLength", "force", "materialStrength", "area", "density"], "properties": { "length": { "description": "Unit of node coordinates and dimension anchors.", "enum": ["m", "cm", "mm", "ft", "in"] }, "sectionLength": { "description": "Unit of section dimensions (d, outerDiameter, thickness, w, h). A separate category from `length`.", "enum": ["mm", "cm", "in"] }, "force": { "description": "Unit of nodal load components. `kg` here means kilogram-force (1 kg = 9.80665 N), not mass.", "enum": ["kN", "N", "kg", "kip", "lbf"] }, "materialStrength": { "description": "Unit of a material's EModulus and fMax.", "enum": ["MPa", "N/mm²", "GPa", "ksi", "psi"] }, "area": { "description": "Unit of a custom section's area. Its Imin uses the matching fourth-power unit: mm² → mm⁴, cm² → cm⁴, in² → in⁴, ft² → ft⁴.", "enum": ["mm²", "cm²", "in²", "ft²"] }, "density": { "description": "Unit of material density.", "enum": ["kg/m³", "lb/ft³"] } } }, "nodes": { "description": "The joints of the truss. Ids are unique integers within this list.", "type": "array", "items": { "type": "object", "additionalProperties": false, "required": ["id", "x", "y"], "properties": { "id": { "type": "integer" }, "x": { "description": "Horizontal position in `units.length`. Increases to the right.", "type": "number" }, "y": { "description": "Vertical position in `units.length`. Increases upward — not screen coordinates.", "type": "number" } } } }, "members": { "description": "Straight bars between two nodes. A member must join two different nodes — `from` and `to` can't be the same. Ids are unique integers within this list.", "type": "array", "items": { "type": "object", "additionalProperties": false, "required": ["id", "from", "to", "section", "material"], "properties": { "id": { "type": "integer" }, "from": { "description": "Id of the node at one end.", "type": "integer" }, "to": { "description": "Id of the node at the other end.", "type": "integer" }, "section": { "description": "Id of an entry in `sections`.", "type": "integer" }, "material": { "description": "Id of an entry in `materials`.", "type": "integer" } } } }, "supports": { "description": "Restraints that hold nodes in place. A pin fixes both x and y; a roller fixes only one of them. Ids are unique integers within this list.", "type": "array", "items": { "type": "object", "additionalProperties": false, "required": ["id", "node", "x", "y"], "properties": { "id": { "type": "integer" }, "node": { "description": "Id of the restrained node.", "type": "integer" }, "x": { "description": "true = the node can't move horizontally.", "type": "boolean" }, "y": { "description": "true = the node can't move vertically.", "type": "boolean" } } } }, "nodalLoads": { "description": "Point forces acting on nodes. Ids are unique integers within this list.", "type": "array", "items": { "type": "object", "additionalProperties": false, "required": ["id", "node", "x", "y"], "properties": { "id": { "type": "integer" }, "node": { "description": "Id of the loaded node.", "type": "integer" }, "x": { "description": "Horizontal force component in `units.force`. Positive points right.", "type": "number" }, "y": { "description": "Vertical force component in `units.force`. Positive points up, so gravity loads are negative.", "type": "number" }, "mode": { "description": "Optional, and only changes how the load's arrow is drawn — the analysis is the same. Leave it out for `push`, where the arrow points at the node. Use `pull` for a load hanging from the truss, such as a downward load on a bottom chord node: the arrow then starts at the node and points away, instead of being drawn across the truss's members.", "enum": ["push", "pull"] } } } }, "materials": { "description": "The material library. Must contain at least one material, even if no member uses it. Ids are unique integers within this list.", "type": "array", "minItems": 1, "items": { "type": "object", "additionalProperties": false, "required": ["id", "name", "EModulus", "fMax", "density"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "EModulus": { "description": "Young's modulus (stiffness) in `units.materialStrength`.", "type": "number", "exclusiveMinimum": 0 }, "fMax": { "description": "Strength limit in `units.materialStrength`. The strength check compares member stress to this.", "type": "number", "exclusiveMinimum": 0 }, "density": { "description": "Mass per volume in `units.density`. Only affects the total mass, not the analysis.", "type": "number", "exclusiveMinimum": 0 }, "color": { "$ref": "#/$defs/color" } } } }, "sections": { "description": "The cross-section library. Must contain at least one section. Which size fields a section has depends on `sectionType`. Ids are unique integers within this list.", "type": "array", "minItems": 1, "items": { "type": "object", "required": ["id", "name", "sectionType"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "sectionType": { "description": "solid_round: d. pipe: outerDiameter, thickness. rectangle: w, h. hollow_rectangle: w, h, thickness. custom: area, Imin. Area and Imin of the first four are computed from their dimensions — don't add them.", "enum": ["solid_round", "pipe", "rectangle", "hollow_rectangle", "custom"] } }, "allOf": [ { "if": { "properties": { "sectionType": { "const": "solid_round" } }, "required": ["sectionType"] }, "then": { "$ref": "#/$defs/solidRoundSection" } }, { "if": { "properties": { "sectionType": { "const": "pipe" } }, "required": ["sectionType"] }, "then": { "$ref": "#/$defs/pipeSection" } }, { "if": { "properties": { "sectionType": { "const": "rectangle" } }, "required": ["sectionType"] }, "then": { "$ref": "#/$defs/rectangleSection" } }, { "if": { "properties": { "sectionType": { "const": "hollow_rectangle" } }, "required": ["sectionType"] }, "then": { "$ref": "#/$defs/hollowRectangleSection" } }, { "if": { "properties": { "sectionType": { "const": "custom" } }, "required": ["sectionType"] }, "then": { "$ref": "#/$defs/customSection" } } ] } }, "dimensions": { "description": "Optional measurement lines between two nodes. Leave the key out to keep the existing ones; include it, even as [], to replace them.", "type": "array", "items": { "$ref": "#/$defs/dimension" } } }, "$defs": { "solidRoundSection": { "type": "object", "additionalProperties": false, "required": ["id", "name", "sectionType", "d"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "sectionType": { "const": "solid_round" }, "d": { "description": "Diameter in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "color": { "$ref": "#/$defs/color" } } }, "pipeSection": { "type": "object", "additionalProperties": false, "required": ["id", "name", "sectionType", "outerDiameter", "thickness"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "sectionType": { "const": "pipe" }, "outerDiameter": { "description": "Outer diameter in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "thickness": { "description": "Wall thickness in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "color": { "$ref": "#/$defs/color" } } }, "rectangleSection": { "type": "object", "additionalProperties": false, "required": ["id", "name", "sectionType", "w", "h"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "sectionType": { "const": "rectangle" }, "w": { "description": "Width in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "h": { "description": "Height in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "color": { "$ref": "#/$defs/color" } } }, "hollowRectangleSection": { "type": "object", "additionalProperties": false, "required": ["id", "name", "sectionType", "w", "h", "thickness"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "sectionType": { "const": "hollow_rectangle" }, "w": { "description": "Outer width in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "h": { "description": "Outer height in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "thickness": { "description": "Wall thickness in `units.sectionLength`.", "type": "number", "exclusiveMinimum": 0 }, "color": { "$ref": "#/$defs/color" } } }, "customSection": { "type": "object", "additionalProperties": false, "required": ["id", "name", "sectionType", "area", "Imin"], "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "sectionType": { "const": "custom" }, "area": { "description": "Cross-section area in `units.area`.", "type": "number", "exclusiveMinimum": 0 }, "Imin": { "description": "Smallest second moment of area, in the fourth-power unit matching `units.area`. The buckling check uses it.", "type": "number", "exclusiveMinimum": 0 }, "color": { "$ref": "#/$defs/color" } } }, "color": { "description": "Optional hex color, e.g. \"#1D4ED8\". Leave it out to keep an existing entity's color.", "type": "string", "pattern": "^#[0-9a-fA-F]{6}$" }, "dimension": { "type": "object", "additionalProperties": false, "required": ["id", "from", "to", "kind", "anchor"], "properties": { "id": { "type": "integer" }, "from": { "description": "Id of the node the line measures from.", "type": "integer" }, "to": { "description": "Id of the node the line measures to.", "type": "integer" }, "kind": { "description": "What the line measures between its two nodes: `horizontal` the distance along x, `vertical` the distance along y, `angle` the straight distance, drawn slanted parallel to the two nodes. All three show a length; `angle` does not measure degrees.", "enum": ["horizontal", "vertical", "angle"] }, "anchor": { "description": "A point the line is drawn through, in `units.length` — it sets how far the line sits from what it measures. A `horizontal` line is drawn at the anchor's y, a `vertical` line at the anchor's x, and an `angle` line through the anchor. Moving a node leaves the line where it is.", "type": "object", "additionalProperties": false, "required": ["x", "y"], "properties": { "x": { "type": "number" }, "y": { "type": "number" } } } } } } }