Prepare and generate a frame

Prepare, review and generate

1. Open and save the top-level assembly in the intended configuration.
2. On the beamng.cad CommandManager tab, open Settings. Check Python, Blender, CGAL Python, Calibration Python (3.11+, NumPy, SciPy, Matplotlib), material/settings source, build output, BeamNG installation and the active user profile’s mods folder. Edits persist without a successful build.
3. Select frame component instances, subassemblies, or bodies in the viewport/tree. Open Define Frame, choose Use current selection, and confirm the resolved body list. A face pick selects its owning body. Assign whole components explicitly expands a pick to its owning component. Expand selection sets into their members before assigning them.
4. Open Hull settings to adjust grid resolution, surface offset, weld distance, proxy alpha divisor/offset ratio, and X symmetry (including source-half flip and seam merge distance). Reset hull defaults restores starting values. Coordinates convert automatically from SolidWorks (x, y, z) to BeamNG (x, -z, y): CAD +Y is up, CAD +Z is front; BeamNG +Z is up and -Y is front. The assembly origin and metres are preserved. Older editable assignments migrate with a backup and need fresh preparation; archived generations retain their original convention. X symmetry is opt-in.
5. Choose Prepare / preview frame. Selected bodies are freshly exported into an external build directory. Blender and CGAL run in the background. Review the temporary orange wire hull in SolidWorks. Show hull overlay hides/shows it without discarding the prepared geometry. Choose Accept hull / review fixtures.
6. In the fixture viewport, check the up/front arrows and select support and load nodes. Right-drag to orbit; click nodes to toggle membership in the selected fixture role. Review load fractions, then Approve orientation and fixtures. Suggestions from a previous graph are spatial suggestions, never inherited approval.
7. Calibrate CAD frame derives targets from this generation’s CAD bodies and their assigned SolidWorks materials. It generates the solidworks-assigned case. Use Package calibrated mod after the offline criteria pass. Verify in BeamNG separately launches the isolated harness, measures the result and reports qualification. Archived annealed/normalized studies remain readable. Open generation… resumes a saved generation; changed inputs require a new one.
8. Open Manage Mod to set the vehicle name, brand, author, configuration, description and selector image. Capture SolidWorks viewport uses the active document’s current view: arrange the angle, zoom and visible components first. The manager hides during capture and shows the resulting thumbnail for review. You can also choose an image or Use hull image to make a thumbnail from the build’s actual hull. Save for future builds persists these settings; Apply to selected build creates a new package revision without regenerating geometry. Then Install selected build installs it. Choose build switches to a previous receipt; folder buttons open its output or the configured mods folder. Enable Reinstall / overwrite to replace even an identical installed ZIP, with a backup. Installation does not launch BeamNG.

Calibration and verification compare each generation with its own CAD-derived mass, inertia, stiffness and yield targets. The archived 34.789158 kg / 78-node / 435-beam Mochi result is only an unchanged-input regression fixture. New geometry can legitimately have different mass and topology. See calibration integration.

Review installation and package identity

The manager compares the selected package hash with the installed ZIP and shows its actual selector name and whether it includes a preview. This is an on-disk check, not confirmation of the vehicle currently spawned in BeamNG. Reopen the vehicle selector after installing; reload the mod or restart BeamNG if necessary. Each project has a stable package namespace. Changing its display name does not change that identity or produce a second installed copy; the manager shows the actual ZIP path. Importing/forking a physics template creates a new identity. Legacy standalone packages may still be named ak1di_mochi.zip. Replaced ZIPs are backed up outside the mods folder. Other projects are left alone. Use the active BeamNG user folder’s mods directory, not the Steam game installation’s mods directory. A common active directory is %LOCALAPPDATA%\BeamNG\BeamNG.drive\current\mods; the startup log confirms it. An older ZIP in the Steam installation folder can therefore differ from the three packages shown in the game’s Mod Manager.

The mod profile is %LOCALAPPDATA%\beamng.cad\mod-profile.json, with managed JPEG images beside it in mod-images. Images are normalized to 1024x576 without distortion and included as default.jpg and base.jpg. Package revisions retain their parent receipt; original builds and geometry remain unchanged.

Resume and refresh saved work

Generate Frame Mod opens the same workflow with the saved frame assignment. Show Frame Selection restores its original selection scope. The modeless frame window leaves the assembly tree and viewport available. Closing it removes the preview; generated geometry is never added to the assembly. The Selected geometry and Preparation log tabs keep the assignment and worker output accessible. Settings edits invalidate the old preview and disable acceptance until Prepare / preview frame succeeds again.

Assignments and hull options are stored beside the assembly in <assembly-file>.truemesh-prep.json, by configuration and role. Keep this companion file with the assembly. Regenerate after CAD edits; missing or suppressed references produce diagnostics and require an explicit replacement selection.

Settings live at %LOCALAPPDATA%\beamng.cad\settings.xml. If absent, the add-in loads legacy %LOCALAPPDATA%\TrueMeshExporter\settings.xml and preserves that original when saving the new settings. Existing build receipts remain supported. Known local installations supply missing defaults; check them for your workstation.

Choose Build directory in the frame window (or Settings) to place new CAD exports, generations, packages and worker scratch files on another drive. Existing generations remain at their original locations. Verification writes beside the generation being tested; regenerate on the new drive to move that work too.