View and inspect
3D models on Windows

Installation

3D Explorer is distributed through the Microsoft Store as a single package that installs both the desktop app and the Windows Explorer shell extensions.

🔄 What gets installed

The Interface

3D Explorer has a simple left-hand navigation. You can open a model by clicking Open a model…, dragging a file onto the window, or launching it from Windows Explorer.

📂 Opening a model

1. From Windows Explorer. Double-click a 3D file, or right-click it and choose Open with 3D Explorer. From the preview pane, the right-click menu has Open with 3D Explorer.
2. From the app. Click Open a model… on the Home page, or Open another 3D file… on the Model page.
3. Drag and drop. Drop a file anywhere on the window.
4. From Recent. Pick a model you opened before.

A large file takes a moment, and the view says where it has got to rather than leaving you with a spinner, Reading the file while the reader works through it and Preparing the view while the model is handed to the graphics card. A model that is cut short by a limit, or that holds something that could not be read, says so when it arrives, see Limitations.

Windows Explorer Integration

Once 3D Explorer is installed, Windows Explorer gains thumbnails, a live preview pane, and file details for 3D files — no extra steps required.

⚡ How thumbnails and previews stay fast

Explorer asks for a thumbnail for a whole folder at once, and a single scan or sculpt can hold a hundred million triangles, so the handlers work to a budget. A model above the ceiling is simplified for its picture, a read that runs past the time limit shows what it got and says so, and both ceilings are yours to raise in Settings. The app itself has no such budget, a model you opened deliberately is drawn in full.

Two kinds of file skip the work entirely. A 3MF package and a sliced G-code program often carry a picture their authoring tool already rendered, and that picture is decoded and returned as the thumbnail, with no geometry read at all.

👁️ Using the preview pane

The 3D Explorer preview pane is a compact version of the full viewer, and it is live rather than a picture. Drag to orbit, hold the middle button to pan, scroll to zoom, and right-click for the rest:

A choice made from the right-click menu applies to the preview you are looking at. To keep it, choose Use these choices for all previews: 3D Explorer opens on its Settings page with your choices saved as the defaults, and every model you select in Explorer then uses them. What it saves is Wireframe, Annotations, Ground shadow, Matte surfaces, Transparent with its Transparency amount and Automatic colours, under How Explorer draws thumbnails and previews, which draw the thumbnails too, plus the Orientation cube and Pointer highlight switches, which the Model page's Show menu shares. Points, the outline, the explode, the ground grid, the four views, the fit and the up axis stay with the preview. A change made in Settings shows up in a preview that is already open, there is no need to close Explorer or to keep 3D Explorer running.

Better Shell Integration (administrator required)

3D Explorer can register its handlers with Windows itself. This turns on the model thumbnails, the preview pane, and the Explorer file details / properties for all supported 3D files. Because it changes the machine, Windows asks for administrator approval when you turn it on or off.

🛠️ Install, update, uninstall

Everything is done from Settings → Shell Integration. The card shows the current status and the matching action button, and each action prompts for administrator approval (a standard Windows UAC dialog).

⚙️ Why it needs administrator, and why updates are separate

Windows resolves thumbnail and preview handlers from a location that only an administrator can write. That is why this integration asks for approval. It's copied to a stable folder outside the app package, so it keeps working across app updates. Because it lives outside the app package it doesn't update itself, so a newer app version flags update available and one click refreshes it.

Viewing Models

The Model page is the viewer. A toolbar runs above the model and wraps rather than hiding anything in a menu, and it always follows the view — drag the model and the zoom box updates itself.

🖱️ Orbit, pan & zoom

The angles, the zoom and the up axis are shown in the bottom-left corner of the view, so you always know where you are, (auto) meaning the up axis is the one the file was read with. Going to Settings or Export and coming back finds the view exactly as you left it, the angle, the zoom and the toggles. Zoom goes from 10 % to 10,000 %. Past about 200 % the view stops moving closer and zooms like a telephoto lens instead, so you can look deep into a detail without ever passing through the surface. Pan to the detail first, since the view magnifies what is in the middle. A model turns around what you are looking at rather than around its original centre, so panning to a detail and then orbiting keeps that detail in front of you.

A drag turns the model as if you were holding it: drag left and its front turns left, drag up and it tips away from you, the way Maya and Blender do it. Three settings in the Mouse group of Settings change how it feels, in the app and in the preview pane alike: Turn the camera instead of the model for the opposite feel, Turn around the point under the mouse so a detail far from the middle stays in view while you turn, and Turning speed.

🔍 Fitting and resetting

🎨 Background colour

The Background color button opens a colour picker for the view. Transparent hands the choice back to the app, which then uses a backdrop that matches your Windows theme. The same colour is used by the Explorer preview pane, and it is remembered between sessions.

Views, Grid & Wireframe

The Show button on the Model toolbar holds every switch that changes how the model is drawn, each with its keyboard shortcut written beside it. They apply at once and they combine. The outline, the explode and the transparency have controls of their own, described below.

🕸️ Wireframe

Draws the triangle edges instead of the shaded surfaces. It is how you see the density of a mesh, where a scan is heavy and where it is coarse, and the seams a shaded view hides. The wireframe's colour follows the background by default, and you can force one in Settings.

⠿ Points

Draws the vertices of the mesh as dots instead of the surfaces. It is the drawing for a scan or a point cloud, and the one that still reads on a dense mesh, where a wireframe turns into a solid black. Each dot keeps its own vertex colour, so a coloured scan stays coloured, or takes the wireframe colour when you set one. Nothing solid is on screen, so no ground shadow is drawn under it.

🎨 A colour per surface, a colour per part

A colour per surface (Ctrl+Shift+S) gives every surface of the model a colour of its own instead of the colours the file carries. In a mesh file a surface is a set of triangles that touch, so a single grey STL reads as the pieces it is really made of. A colour per part (Ctrl+Shift+A) does the same for the parts of an assembly, so they read apart from each other without exploding the model.

The colours are worked out from the file itself, so the same model always comes out the same, and what you export carries them. Explorer can draw its thumbnails and its previews this way too, see Settings.

🔦 Pointer highlight

Move the pointer over the model and the part under it lights up and is named at the top of the view, with its triangle count and its size. It is the quickest way to tell which piece of an assembly you are looking at, and it costs nothing to try, since it draws over the model rather than changing it. Turn it off in the Show menu (Ctrl+Shift+H).

🎬 Showcase

Takes the model on a tour chosen from the model itself. A flat part is seen from higher up, a long one is swept along its length, and an assembly comes apart and has its largest parts picked out one by one, each round ending with a closer look. The first drag, click or scroll hands the view straight back to you. It is in the Show menu, and it is the fastest way to see what an unfamiliar file holds.

🌑 Ground shadow, matte surfaces, annotations

Three more switches in the Show menu. The ground shadow (Ctrl+Shift+D) puts the model on a surface instead of leaving it floating. Matte surfaces (Ctrl+Shift+M) take the shine off, which is what a shape reads best under. Annotations (Ctrl+Shift+N) show the notes a file carries, when it carries any. Explorer draws its thumbnails and previews by the same three, each with its own setting.

💥 Explode

The Explode slider at the top left of the view pulls the pieces of a model apart from its centre, smoothly, from nothing to fully apart. It is offered for a scene of several objects and for a single mesh that is made of several disconnected shells, since those come apart into them. Drag it back to zero and everything returns exactly where it was, and what you export is what you are looking at. How far "fully apart" throws a piece is the Explode reach setting, see Settings.

🫧 Transparency

The Transparency slider, under the Explode one at the top left of the view, draws the model see through, so a part standing inside another one shows without moving anything. Drag it back to zero for the solid model again. The outline, the annotations and the pointer highlight keep working while it is on, and it is exactly what you are looking at that an export writes. An Outline only drawing is never see through, and neither is a Points one, there is no surface left to see through, so the slider greys out there rather than moving and doing nothing. It keeps its value and comes back with the surfaces.

How far the slider goes is the Transparency setting, and a preview pane in Explorer offers the same thing under Transparency in its menu, solid or one of four amounts.

🧊 Orientation cube

The cube in the top-right corner of the view turns with the model and says which way you are looking at it. Click one of its faces for a straight front, back, left, right, top or bottom view, or one of its edges or corners for the view between them, which is the quickest way back to a three quarter view after orbiting. It is chrome, so it is never part of an export or a thumbnail, and the Show menu turns it off.

✏️ Outline

The Outline button (Ctrl+Shift+E) offers three drawings: No outline, Outline over the surfaces and Outline only. The outline is the model's sharp edges, its borders and every edge where two faces meet at more than about 30°, plus its silhouette, the rim where a curved surface turns away from you. A cylinder shows its two rims and its two sides, never the strips it is built from. Whatever is behind the model is hidden, so Outline only reads like a technical drawing, not like a wireframe, and the Wireframe button is disabled while it is on.

The lines get bolder as you zoom in, and thinner in a small view such as a thumbnail. Their colour is in the same menu: Automatic picks a deep blue or a cyan, whichever stands out from the model, or from the background for an outline alone, and you can choose your own. A model opens with no outline, and a choice you make holds for the files you open after it. Width is a number of pixels or Computed, which grows the line as you zoom in and thins it in a small view, and Heavier silhouettes, thinner with distance weights the drawing the way a pen would, the rim of the model heavier than the creases inside it.

🧭 Ground grid and axes

Puts a grid on the plane the model stands on, with the three axes at its centre — X red, Y green and Z blue, the convention every modelling tool uses. They are the file's own axes, so a Z-up model stands on a blue axis, and choosing another up axis moves the colours with it. The squares are a round number of the model's own units, so the grid also tells you how big the thing is. The grid's colour is worked out from the background, so it reads on a dark backdrop and on a light one.

🪟 Four views

Splits the view into the 3D view at the top left plus straight Front, Side and Back views, each labelled in its corner. The three straight views are orthographic, so a length reads true and parallel edges stay parallel, which is what makes them useful for checking proportions.

🔃 Up axis

Some formats say which way is up and some do not. An STL, an OBJ or a PLY carries no up axis at all, so 3D Explorer reads it by convention, Z up for an STL like every slicer, Y up for an OBJ. When a file breaks the convention the model lies on its side, or stands on its head. The Up axis menu next to Reset view picks which of the file's own axes points up: +Z, −Z, +Y, −Y, +X or −X, or Automatic to go back to how the file was read. The model is refitted, and an export writes it the way it is now shown.

Every choice turns the model, none of them mirrors it. A mirrored part is a different part, a left-hand bracket becomes a right-hand one, so a model is never flipped left to right. If a text on a model seems to read backwards, it is almost always being seen from behind: orbit round it, or pick another up axis.

Model Properties

The Properties button on the Model page opens everything the product knows about the open file. It is the same set the Explorer details pane publishes, so the two can never disagree.

🪟 In Windows Explorer

The same facts reach the Explorer Details pane, mapped onto the Windows properties every application understands, so they also show in the tooltip and in any column you add to a folder view.

Exporting

The Export page writes what is open as a picture, a drawing, another 3D model, or a CAD file. Pick a format, choose the views and the sizes, and everything else on the page follows the choice.

🧭 Views and sizes

Tick any of 3D, Front, Side and Back, and give one or more sizes in pixels separated by commas. Each combination becomes a file. A PDF or an SVG takes its page size from the same number. A model file and a 3D drawing carry the whole scene, so they ignore the view.

Current view is exactly what the Model page is showing, its angle, its zoom, its explode and its transparency. A see through model is written see through in every view of an export and not only in the current one, since that is how the model is being looked at. A PDF or an SVG of an exploded or a see through model holds a rendered picture rather than one shape per triangle, a flat projection has no depth to show one surface through another with. A wireframe and a points drawing are vector too, a shape per edge and a shape per vertex, so they answer to the shape limit the way a shaded drawing does, where an outline never does, it is a few hundred lines whatever the model.

You can also say which you want. Contents, beside the format, offers Vector shapes when they are worth it, which is the default and weighs the drawing against the shape limit, Always vector shapes, whatever the file ends up weighing, and Always a rendered picture, which any view can be written as. An exploded or a see through view cannot be drawn as shapes at all, so that choice greys out there. Under the format, one line always says what your choices will produce and why, so a drawing is never silently a picture.

A vector drawing welds the triangles of one shade into whole surfaces, which is what makes it a drawing of the model rather than of its mesh, a fraction of the size and far closer to what you see. Each shape is stroked in its own colour so that two neighbours do not leave a hairline of the page between them. That stroke is kept to the width of the triangle it belongs to, and in an SVG it does not grow with the zoom, so zooming into a drawing shows the model and not the strokes. Even so, a flat drawing sorts whole triangles where the screen sorts every pixel, so on a dense assembly some surfaces land over ones that should cover them. When that shows, the rendered picture is the honest answer.

🏷️ File names

The File name box is a pattern rather than a name, and the page shows an example of what will be written as you type. The tokens are listed in File Name Tokens.

✏️ Drawing style, outline and wireframe

An image, a PDF, an SVG or a flattened CAD drawing can be drawn three ways: Shaded surfaces, Outline only, or Outline over the surfaces. An outline is the silhouette plus the edges sharp enough to read as edges, with whatever sits behind a surface left out, the same drawing as the Outline button of the Model page. In a PDF or an SVG it is also a fraction of the size of a shaded drawing, and much closer to a technical drawing. The preview shows the style you chose. Edge angle decides how sharp an edge has to be to show, Line width and Line color do what they say, and Automatic picks an ink that reads on the page. The wireframe option draws every edge instead of the surfaces, in a picture and in a drawing alike.

📐 DXF and DWG options

🏃 Running an export

Click Export, or press Ctrl+E. The page is busy while it writes, since a large model takes a moment, and a message tells you so rather than leaving the window looking frozen. When it finishes a toast says how many files were written and where, names anything written beside them, and says how many were left alone when a file of that name was already there and overwriting is off. Open folder takes you to the result. Anything that goes wrong is reported in the same place, with the reason.

The page also refuses an export that cannot work, before it starts: no folder, no name, no view, no size, or a name that would make several files overwrite each other. The message says which, and the Export button stays disabled until it is fixed.

📦 Files written beside the file

Some formats need company. An OBJ writes its .mtl material library and copies its textures beside it, a .gltf writes its buffer and its images, a PLY notes its texture by convention. A GLB or a 3MF packs everything inside the one file. The toast that appears when the export finishes lists what was written, side files included, and Open folder takes you straight there.

Recent Files

The Recent page keeps a list of the models you have opened before, so you can jump back to one quickly.

Settings

The Settings page groups the app's options. Viewing choices you make in context — zoom, background, the toggles, the export options — are remembered on their own.

Appearance and behaviour

Mouse

Rendering

Reading limits

Every one of these can leave a preview partial, and a preview that was cut short says so. Raise one when you meet it.

Explorer integration

The About section shows the app version and a link to detailed System Information — useful when reporting an issue. Your export folder, name pattern, sizes, colours and background are remembered automatically between sessions.

Diagnostics

The last row of About is Diagnostics, a report to send support when something goes wrong, in the app or in File Explorer, a thumbnail or the preview pane.

1. Choose Problems only, or Everything when support asks for more detail. The row then shows until when it records.
2. Make the problem happen again, in the app or in File Explorer.
3. Click Save report. One file lands on your desktop, selected in File Explorer, ready to attach to an email.

Supported Formats

Input — what 3D Explorer reads

Meshes, whole scenes, and the toolpath programs a slicer or a machine tool produces.

Containers — a whole model in one file

A model is often a SET of files, an .obj with its material library and its textures. 3D Explorer opens them together from a folder, or from an archive:

Export

Raster exports cover the image formats registered on your Windows system. A green dot marks formats that keep transparency, a blue dot marks vector formats.

File Name Tokens

The File name box on the export page is a pattern. Tokens are case-insensitive, and a token the chosen format has no use for is simply left out of the name, so one pattern can serve every format.

Keyboard & Mouse

The same three gestures in the app and in the Windows Explorer preview pane.

Keyboard, in the app

Every item of the Show menu has one, and the menu writes it beside the item, so the menu teaches them as you use it.

In the model viewer

In the Windows Explorer preview pane

Limitations

3D Explorer is a fast, faithful viewer, inspector and converter — not a modelling tool, a mesh repair tool or a slicer. Knowing what it focuses on, and where a format itself sets the limit, helps set expectations.

🛠️ Viewing and converting only

There is no editing. You cannot move a part, retopologise a mesh, fix a non-manifold edge, hollow a model for printing or generate supports. Exporting to another format converts what was read, it does not repair or optimise it. Before you print or machine a part, check it in the tool that will make it.

🚫 Blender documents are not read

A .blend file is a memory dump of Blender's own internal structures rather than an interchange format, and reading its geometry means reimplementing Blender's type system and following it across releases. 3D Explorer does not read one. Export from Blender to glTF, FBX or OBJ and all three open here.

🧍 Animation, rigs and cameras

A rigged or animated scene is drawn in its bind pose, which is what a thumbnail of a character should be. Skins, animation stacks and poses are counted in the properties and nothing more. Cameras and lights in a scene are not used, the viewer lights every model the same way so two models can be compared.

🗜️ Compressed geometry

A glTF whose meshes are packed with the Draco extension is reported as unsupported rather than shown empty. Re-export it without Draco and it opens normally.

📏 Derived figures are estimates

The size in millimetres is the model's bounding box, and it depends on the unit the file declares. A format that declares no unit is taken at face value, so a model authored in centimetres and saved without saying so will read ten times small. The declared unit and up axis are always shown in the properties, so you can tell.

🧵 A toolpath is interpreted, not simulated

A G-code program is drawn by following its moves and giving them width, which shows the printed object or the path a tool takes. It is not a machine simulation, there is no material removal, no collision checking and no time estimate of our own beyond what the file states.

⚖️ Very large models are capped

Reading limits stop one file exhausting your machine, and the Explorer handlers apply a further budget so a folder of huge models never hangs File Explorer. When a limit is met the model still appears, marked partial, and the details say which one. Every limit is a setting you can raise, see Settings.

🥇 One thumbnail / preview provider per file type

Windows lets one handler own a file type at a time. If another application is registered for .stl or .obj, its thumbnails win. Better Shell Integration is the fix, it registers 3D Explorer's handlers with Windows as a fall-through.

🖱️ Preview pane stops responding after double-clicking a file (Windows 11)

On recent Windows 11 updates, double-clicking the file you are previewing, to open it, can leave the preview pane unable to react. The preview is still drawn, but the pointer keeps a resize arrow over it, and clicks, drags and the wheel do nothing. Windows starts a second preview of the file as it opens it and leaves an empty window of its own over the first one. It happens with the previews Windows ships too, a text file double-clicked into Notepad for instance, and it does not happen on Windows 10.

🚫 Preview stays blank for files downloaded from the internet

Starting with Windows 11 25H2, Microsoft blocks the File Explorer preview pane for files that carry the "Mark of the Web" — files downloaded from the internet, or coming from a location Windows considers unsecured. This affects every file type, not just 3D models, and it is a Windows security decision: there is nothing 3D Explorer can do at its level to override it.

Tips & Tricks

📦 Package a model as one shareable file

Zip the folder holding a model and everything it links to, then rename the archive to .3dzip — or, if you compress with RAR, to .3drar. Either one carries a 3D Explorer thumbnail and preview in Windows Explorer and opens as the complete model, textures included, with a double-click.

🔬 Reading a dense mesh

Turn on the wireframe to see how a model is built and where its detail is, and the ground grid to judge scale. Four views beside them is the quickest way to check proportions, since each straight view can be zoomed and panned on its own.

🌙 Dark mode

3D Explorer follows your Windows theme by default. For a fixed look, choose Light or Dark explicitly in Settings. The view's backdrop, the wireframe ink and the ground grid all follow whichever you land on, unless you pick a colour of your own.

Troubleshooting

🖼️ A model that opens grey or untextured

Its textures are missing. 3D Explorer looks for them where the model says, then anywhere under the model's own folder, so the usual cause is that the images were never sent with the file. The bar over the view names the ones it could not find. Ask for the model as a GLB or a 3MF, both of which carry their images inside the file.

🔒 "File system error (-2143322102)" when opening a file

If double-clicking a file, or choosing Open with → 3D Explorer, shows a message with the file's path and File system error (-2143322102), your free trial has ended. Windows refuses to start an app whose Store licence is no longer valid, and that number is the Store's licensing error, 0x803F800A, which Windows shows without an explanation. Nothing is wrong with the file.

🖼️ Thumbnails only show in the icon views

Windows draws thumbnails in Explorer's icon views only. A folder in Details or List view shows the plain file type icon instead, whatever the file is. Your Pictures folder opens in Large icons, which is why models look right there, while Documents, Downloads and a USB stick open in Details view. The folder and the drive make no difference, the view does.

In a folder where thumbnails are missing, open the View menu of the Explorer toolbar and choose Medium icons, Large icons or Extra large icons. Holding Ctrl and turning the mouse wheel does the same, and Windows remembers the choice for that folder.

👁️ The preview pane stays empty

The preview pane belongs to Explorer, not to 3D Explorer, and Windows keeps it closed until you ask for it, in each Explorer window separately. Press Alt+P, or use View → Preview pane, in the window where you want it. A second window needs the same.

On Windows 11 the Details pane and the Preview pane cannot be open at the same time, so turning the details pane on closes the preview. The Open and Save dialogs of other programs have no preview pane at all, whatever is installed.

🥇 Thumbnails or previews don't show (another app is the default)

Windows follows the file type's default app for thumbnails and previews. If another program handles a 3D extension and is set as default, its thumbnails win. The quickest fix is Better shell integration:

1. Open 3D Explorer's Settings → Shell Integration (see Better Shell Integration) and click Install. Approve the administrator prompt.
2. 3D Explorer's thumbnails, preview and details now show for all supported files, regardless of which app is the default.

Prefer not to use Better Shell Integration? You can instead make 3D Explorer the default app for an extension in Windows Settings → Apps → Default apps. Either way, run Settings → Reset Thumbnails if old cached thumbnails linger.

🔃 A model lies on its side, or stands on its head

The file uses a different up axis than its format's convention, which STL, OBJ and PLY files cannot declare. Pick the right one from the Up axis menu on the Model toolbar (Ctrl+Shift+U), or from the preview pane's right-click menu, see Views, Grid & Wireframe. For a file from a CAD tool, +Z or +Y is nearly always the one. Export it afterwards as a 3MF and the orientation is written into the file for good, 3MF declares its up axis.

🔄 Thumbnails look out of date?

After changing colours or thumbnail settings, click Reset Thumbnails in Settings. You can also clear Windows' cache with Disk Cleanup: press Win+R, run cleanmgr, tick Thumbnails, and click OK.