Components and materials

Open Frame workflow > Components / mounts. Assignments live beside the saved assembly in <assembly>.beamng-project.json, including persistent CAD references, configuration, body IDs, role tags, generation settings and mounting points. Tagging does not require a completed frame package or a successful hull preview.

Choose the template set first

On Vehicle setup / MVP, choose front suspension, rear suspension and drivetrain, then Apply vehicle setup. Required groups and associations come from those choices in FramePipeline/template_catalog.json.

Input schemas include front double wishbone or MacPherson strut, rear trailing arms or double wishbone independent suspension, and CVT rear drive with or without the rear differential’s geared front output. Defaults match the Mochi layout: front wishbones, rear trailing arms, CVT into rear differential with a geared output feeding the front differential. Full-vehicle generation currently supports front wishbones with either trailing-arm or wishbone rears. The strut option is an inventory schema for future work. Choosing a setup does not qualify the vehicle: ratios, joints and hardpoints still require actual inputs and native verification.

Changing a setup retains existing selections. Tags no longer requested appear as OUTSIDE CURRENT SETUP. Revise them or change the setup before packaging.

Tag the CAD groups

1. Choose an MVP role and click New tagged group. Give it a useful name. The role supplies a starting representation. Full-vehicle generation replaces suspension-group collision previews with the template’s parametric mechanisms; bulk and panel groups retain their corresponding generated representations.
2. Select CAD bodies or faces and click Assign current selection. A face means its entire owning body. Solid and surface bodies are supported. For a whole component or subassembly, use Assign whole components; selecting its edge or feature is sufficient for that explicit action.
3. Repeat for the checklist groups. Each body belongs to one assignment. Group meshes of one rigid part together; separate parts that need independent motion or breakaway. Multiple panels/accessories are allowed. Use Use saved frame for the calibrated frame.
4. To tag an existing list entry, change MVP role and Save parameters. Show CAD selection recalls its bodies.
5. Click Refresh tagged CAD after assigning groups or changing CAD. This resolves saved selections, exports current geometry/materials, refreshes mounts and writes <assembly>.beamng-project.json.inventory.json.

The inventory contains template choices, missing/duplicate roles, ownership, persistent references, mesh hashes, mass-input issues and planned associations. It is the reusable handoff for iteration. Broken groups are reported without reusing old exports. Tags do not assert that a hinge, shaft or connection has been built or tested. Load a reviewed template definition for mechanism hardpoints, include its mounting plan in fresh frame calibration, then regenerate the vehicle.

From the project root, set $calibrationPython to your configured interpreter and regenerate inventory offline from the last CAD exports:

& $calibrationPython beamng.cad/FramePipeline/component_worker.py inventory --project '<assembly>.beamng-project.json' --output inventory.json

This command does not refresh SolidWorks. Use the UI refresh after CAD edits. Missing groups are valid partial preparation, not vehicle qualification. Geometry files stay in the configured build directory.

Surface weight

For an assigned component, choose:

• Use thickness + SolidWorks material: enter Surface thickness mm. Mass uses native surface area, entered thickness and SolidWorks material density. Mass, center and inertia are fitted to positive node masses. Thickness contributes to inertia without modifying or thickening the CAD body.
• Exclude surface mass: surfaces add zero mass; solid bodies retain their native mass. A group with no positive mass cannot be a physical component. Select Visual only, choose its physical parent (and moving member when applicable), then choose Exclude mass and Accept visual only with excluded mass. It follows its parent’s nodes with no independent collision or breakaway. Put mounts on the physical parent, or supply thickness for separate physics.

Thickness and density must be positive for weighted sheets. They may remain unset while tagging; preview reports missing inputs. Export does not assign materials. Component assignment permits sheets; frame calibration still requires solids.

Representation and mass policy are separate. A Visual only group can also carry CAD or custom positive mass: that mass, COM and inertia are fitted into its physical parent’s nodes once. An infeasible fit is rejected. Excluded mass stays explicitly labelled, and changed geometry/mass settings require renewed acknowledgement.

Generation and mounting

Estimate from CAD suggests panel spacing or bulk alpha-wrap settings. Generate / preview fits mass and displays that component’s representation. The panel template preserves projected openings and adds numerical depth locators. Strongly curved panels require bulk representation for now. Hull visibility uses retained temporary graphics; closing the window disposes them.

Mounting points retain CAD references and local offsets. Select a component entry, then a vertex, point, circular edge, or two points for a midpoint. Use several separated points for a fixed attachment. Connections join distinct component graphs; each fastener has its own break group. Current calibrated-frame connections use reported support patches on existing nodes. Dedicated short parent/child beam pairs require adding parent nodes before fresh frame calibration.

Full vehicle templates distinguish direct structural mounts from release mounts in the frame mounting plan. A direct joint uses existing structural frame nodes. A release mount adds its short parent-node patch before calibration. Changing either the position or representation requires a new frame graph and calibration; changing a dropdown cannot silently alter a sealed frame artifact. Hardpoints also need physical support in the CAD assembly. A successful linkage solve by itself does not establish that a remote mounting point has a bracket or frame member capable of carrying its loads.

Package the project’s calibrated frame before Package components. The package preserves frame provenance, geometry hashes and project identity. Verify component mounts runs settle, load and release recordings in one owned BeamNG session, respawning between recordings. Only changed files are staged; a reload during recording fails the test. Successful tests retain compact measurements/images; failed or explicitly requested diagnostics remain complete.

Panel/accessory stiffness and rupture remain provisional. Mounting verification does not qualify suspension, drivetrain, crash accuracy or unknown material behavior.