MeshOptimiserBeta Download

Docs

Everything, from the first download.

45 short articles, written for someone who has never opened a CAD file in a browser. Start at the top and read down, or search.

Start here

What the app is, what it needs, and how to get from a download to your first model on screen.

  1. What MeshOptimiser isA free app that runs on your own computer. It turns a heavy CAD file into a light 3D file and lets you inspect, clean up and export it.
  2. Words you will meetA plain-language glossary: STEP, mesh, triangle, GLB, instancing, decimation, WebGPU, virtual environment and the other terms these pages use.
  3. What you needWindows or macOS, Python 3.10 to 3.12, a recent browser and about 2 GB of free disk space. How to check and install Python.
  4. Download and unzipGet the zip, unpack it into a normal folder, and learn why there is no installer.
  5. Start it the first timeDouble-click the launcher for Windows or macOS. What the first run sets up, how long it takes, and what you see when it is ready.
  6. Install it as an app windowSince v0.13.0 the app opens in its own window. You can also install it for a desktop shortcut, and fold its title bar away.
  7. Open your first fileDrop a file on the window. What the import settings mean, what conversion does, how to follow its progress, and where the result is kept.
  8. Stop, restart and updateQuit the app cleanly, start it again in a second or two, and move to a newer version without losing your settings.

Find your way around

The window, the mouse, selecting, hiding, the parts tree, search, undo, tabs and settings.

  1. The windowA tour of the screen: the top bar and tabs, the parts tree, the 3D view and its toolbars, the cards on the right and the status bar.
  2. Move the viewOrbit, pan and zoom with the mouse, frame a part with F, and switch between the camera, Top, Front and Side views.
  3. Select partsClick, add with Shift, toggle with Ctrl, drag a box, or let the app select by shape, colour or name.
  4. Hide, isolate, show allHide parts that are in the way, look at a few parts on their own, and bring everything back with one key.
  5. The parts treeSearch, rename, group and reorder the parts of a model, rename many at once, and flatten a hierarchy that is deeper than you need.
  6. Search and commandsPress Ctrl + K to find any command, part or library part by name, and to work out a sum or convert a length.
  7. Undo and redoEvery editing action can be taken back with Ctrl + Z. What counts as one step, and how to go back to the file as it was opened.
  8. Scene tabsEach tab is a scene of its own. Open several files side by side, drag tabs into order, and save from the tab’s icon.
  9. SettingsOne window with six sections and a search. What each section holds, in a sentence or two.

Make it lighter

The tools that remove triangles and parts, one at a time, and a sensible order to use them in.

  1. How to read the numbersWhat a triangle count tells you, where the app shows it, how to find the heaviest parts, and how to see what your work has saved.
  2. Delete small partsRemove the screws, washers and clips that are too small to matter, with a slider and a preview of what will go.
  3. Select hidden partsFind every part that cannot be seen from outside the model, such as screws inside a housing, and delete them in one step.
  4. Fill holesClose bolt holes, slots, pockets and lettering in flat faces. Each closed hole removes the triangles of its walls.
  5. SplitTake apart a mesh that arrived as one piece but is really several separate solids, so each can be selected on its own.
  6. Smart fitReplace a detailed part with a simple stand-in of the same size and position: a box, a cylinder, a few boxes, or blocks that keep its outline.
  7. DecimateRemove a share of the triangles from the selected parts while keeping their shape. Choose a percentage or a target, and preview first.
  8. Fit to budgetType the number of triangles the whole scene may have. The densest meshes are reduced first until the total fits.
  9. Auto cleanup and Tidy geometrySmall one-click repairs: remove empty parts and empty groups, fix shading, recentre the model and make moves permanent.
  10. A sensible order to work inA suggested routine for a first clean-up: look, delete what is not needed, simplify what remains, check, save and export.

Look and arrange

View modes, materials, moving and measuring, standing a model on the floor, and adding parts.

  1. View modesFive ways to draw the same model: solid, wireframe, X-ray, heatmap and clay. One key each, and what each is good for.
  2. Colours and materialsOpen the materials dock to see every material in the scene, recolour all the parts that share one, and assign materials to parts.
  3. Move, rotate, scale and measureUse the gizmo to move, turn and resize parts, type exact values in the transform panel, and measure the distance between two points.
  4. Align to floorStand a model upright on the grid, centred over the origin, when it arrived on its side or far away from the centre of the scene.
  5. Exploded viewPush the parts of an assembly apart with a slider, to see how it is put together.
  6. The parts library and shapesAdd standard parts to a scene: 86 bolts, nuts, pipes, profiles and machine parts, each with sizes you can change afterwards.
  7. ScreenshotsSave a picture of the viewport as a PNG, at the size of the view or at any resolution up to poster size.

Save and export

Keep your work as a scene, or write a file for another program.

  1. Save a sceneSave your work as a scene file so you can carry on later. What a scene file is, and how it differs from an export.
  2. ExportWrite the model to GLB, glTF, FBX, USDZ, OBJ, STL, PLY or a parts list, and set the scale, up axis and origin the next program needs.
  3. Which format should I chooseA short guide by purpose: the web, Cinema 4D, Blender, game engines, AR on an iPhone, 3D printing, or a parts list.

Reference

Every shortcut, every command-line option, the file formats and what is in the folder.

  1. Keyboard shortcutsEvery keyboard shortcut and mouse action in MeshOptimiser v0.13.0, grouped by what it does.
  2. The command-line converterConvert STEP files to GLB without opening the viewer. How to run step2glb.py, and what every option does.
  3. File formatsWhich files the app opens and which it writes, and what each format keeps: the parts tree, materials and vertex colours.
  4. Files in the folderWhat the files and folders inside the MeshOptimiser folder are for, which ones you use, and which ones to leave alone.
  5. Privacy and offline useMeshOptimiser runs on your own computer. What stays local, when the internet is used, and what the browser remembers.

Help

What to do when something goes wrong, and answers to common questions.

  1. TroubleshootingFixes for the usual problems: Python not found, a blocked launcher on macOS, missing modules, a blank view and slow conversions.
  2. Frequently asked questionsShort answers: cost and licence, privacy, browsers, file sizes, whether Python is needed, and where to report a bug.
  3. Self-testFor the curious: the app can test itself. One address runs a suite of checks inside the live app and reports the results.

Run it on your own machine.

Free and open source under the MIT licence. Windows and macOS; your files never leave the computer.

Download v0.13.0 View on GitHub