Everything shown on this page was rendered directly by Heimdall3D from the original files.
A folder of models shows the models
Every 3D file and HDR image in a folder draws its own thumbnail, rendered from the file on disk. A selected model opens in the preview pane, where it can be orbited and its animation played, and double-click opens it full size. HDR images retain their full floating point range and include exposure controls and live pixel values.
Version 1.0.11 is available for Windows 10 and 11.
The free version includes thumbnails, the preview pane, the viewer window, and every supported format. It requires no account or licence key, has no watermarks, and does not expire.
If you want to save or export your work, you can buy the full version. It adds four export features: saving an image, copying a frame to the clipboard, rendering a sprite sheet, and recording a turntable or animation clip.
Heimdall3D is developed by one person, and licence sales fund the work.
If a file does not render correctly, or you would like another format or feature, please tell me. Your requests help decide what gets added next.
Not a wrapper
Heimdall3D is a native 3D renderer for Windows Explorer and Directory Opus. It renders your models itself. Nothing is handed to another engine.
The whole pipeline runs through Vulkan: materials, textures, skinning, shadows, environment lighting, and tone mapping. All of it runs on the GPU already in your machine.
Heimdall3D supports 20 extensions:
We wrote the decoders for 13 of them ourselves: OBJ, PLY, STL, 3DS, 3MF, COLLADA, BVH,
Radiance in both .hdr and .pic, PFM, TIFF in both spellings, and DDS
down to BC7.
The other 7 are read by four pinned libraries. glTF, GLB and VRM come in through cgltf, FBX through ufbx, EXR through OpenEXR, and KTX2 and Basis through Basis Universal. Draco and meshoptimizer decompress the meshes a glTF can carry, and stb_image reads the PNG, JPEG and TGA textures inside a model.
Everything ships in one binary, with no runtime dependencies.
Windows can preview a few 3D formats through Microsoft's 3D Viewer. That component is no longer preinstalled on Windows 11, and animation that once worked stopped after a Windows update. Anything relying on it inherits those limitations.
Heimdall3D does not use it. Its ability to open and render your files does not depend on whether Microsoft installs, removes or changes that component.
A preview pane you can turn
A selected model gets a lit, orbitable view. The camera orbits and zooms, the environment map and the floor can be changed, and any animation the file carries plays.
An HDR image opens in floating point with exposure measured in EV stops, tone-mapping, gamma and channel isolation, and the RGBA value beneath the pointer.
Models can be lit using an HDR environment map, so reflective materials take on the colours around them. Metals reflect the environment, glass filters the light passing through it, and anisotropic materials stretch highlights along their surface direction.
A model that keeps its geometry or its textures in separate files beside it loads them.
A .gltf with its .bin and its texture maps in the same folder opens
complete, in the pane and in the thumbnail alike.
If the pane says a file could harm your computer
The message comes from Windows. It marks every file you download, and it will not run any preview handler on a marked file. The thumbnail still renders and double-clicking still opens the file; only the preview pane is refused.
To clear it on one file, right-click it, choose Properties, and tick Unblock. To clear a whole folder, run this in PowerShell:
Get-ChildItem "C:\path\to\folder" -Recurse | Unblock-File
Most models downloaded from an asset site arrive marked.
Open it full size
Double-click a file and the viewer opens in a window of its own, filling the screen, with everything the preview pane has. F11 gives you the picture and nothing else, and Escape brings the window back.
The window also keeps what you set up: your environment and lighting presets, and the files you opened recently.
Windows protects your choice of default application, so Heimdall3D registers without taking
anything from another program. .hdr and .exr open with it straight
away. For .gltf, .glb, .obj and .fbx,
Windows asks you once and remembers the answer.
Motion capture plays in Explorer
An FBX or BVH clip plays on a rigged mannequin at the frame rate it was authored for. Node animation is supported too.
A motion capture file often contains a skeleton and animation but no visible mesh. Heimdall3D retargets the clip onto the mannequin, so the motion can be seen and inspected.
The animation continues playing while you change the display. Cartoon shading, outlines and depth of field all work in real time. These effects are only applied in the viewer and never alter the original file.
Thumbnails rendered from the file
Every supported file gets a thumbnail rendered from its contents in the Windows Explorer file list. Without Heimdall3D, these types show a blank page icon.
Models appear from a useful camera angle. Motion capture files show the mannequin in a representative pose. HDR images show their contents.
On the test system, a model with 350,000 triangles takes about 1.2 seconds to render. The result is then cached, so it does not need to be rendered again every time you open the folder.
Installing does not disturb thumbnails another program already provides. Where a file type already has one, the previous handler is recorded before Heimdall3D takes over, and put back if you uninstall.
FlightHelmet_Materials_, and the thumbnail is what separates the normal map
from the base colour. The .bin holds geometry rather than a picture, so it
keeps the generic icon.Supported formats
Heimdall3D currently supports twenty file extensions. Thirteen of them are read by decoders written here, and the other seven by one of four libraries pinned at a version and compiled into the binary.
A model format is only listed as supported when Heimdall3D can also load its related materials, textures, skeletons or animation where the format provides them.
Models and motion capture
| Format | Extensions | What Heimdall3D loads |
|---|---|---|
| glTF | .gltf .glb |
Geometry, materials, textures and animation, including WebP and Basis textures and meshes compressed with Draco or meshopt |
| FBX | .fbx |
Geometry, skeletons and animation |
| VRM | .vrm |
Avatars, as the glTF they are: geometry, materials, textures and animation |
| OBJ | .obj |
Geometry and its .mtl materials |
| PLY | .ply |
Geometry, texture coordinates and the texture the file names. ASCII and binary, either byte order |
| COLLADA | .dae |
Geometry, materials, textures and the scene graph. A rigged file opens in bind pose; its animation is not read yet |
| 3DS | .3ds |
Geometry, materials and bump maps |
| 3MF | .3mf |
Geometry, colours, materials, textures and the printing units |
| STL | .stl |
Geometry |
| BVH | .bvh |
Skeleton and animation, played on the mannequin |
HDR images and textures
| Format | Extensions | What Heimdall3D loads |
|---|---|---|
| Radiance | .hdr .pic |
Floating point images opened at full range |
| OpenEXR | .exr |
Floating point images, including single channel files |
| PFM | .pfm |
Floating point images |
| DDS | .dds |
Block compressed and uncompressed texture formats used in game pipelines |
| KTX2 | .ktx2 .basis |
Basis Universal supercompressed textures, transcoded as they load |
| TIFF | .tif .tiff |
8, 16 and 32 bit images, both byte orders, strips and tiles |
Heimdall3D can also decode .png, .jpg, .webp and
.tga, but leaves them to Windows because it already supports them well.
USD is not supported yet. Alembic is not planned: it carries geometry and motion but no materials, and a format is listed here only when it carries its textures and its animation.
The decoders and the renderer ship inside Heimdall3D and change only when it does.
What is free, and what you are paying for
The free version includes thumbnails, the preview pane, the viewer window, and every supported format. It requires no account or licence key, has no watermarks, and does not expire.
The full version adds four export features: saving an image, copying a frame to the clipboard, rendering a sprite sheet, and recording a turntable or animation clip.
These controls remain visible in the free version. If you use one, Heimdall3D explains that it requires a licence and provides a link to this page.
A licence is a one-time purchase and works in both Directory Opus and Windows Explorer.
The Directory Opus plugin
The same viewer ships as a Directory Opus plugin, and the installer offers it when it finds Opus on your machine. One download, one licence, both hosts.
You can clear either one during installation if you only want the other.
Download Heimdall3D 1.0.11
Heimdall3D 1.0.11 is available for Windows 10 and 11. One installer carries the Explorer integration and, where it finds Directory Opus on the machine, the Opus plugin as well.
Download the Installer, 124 MB Download the ZIP, 142 MB
Which download should I use?
Use the installer unless you want a manual installation. It registers the thumbnail and preview handlers, removes any previous version, and restores the thumbnail handler another program had registered when you uninstall it.
The ZIP contains the same files and leaves registration, replacement and removal to you.
Verify the download
The installer and the handlers are not code signed, and there is no plan to sign either.
Windows SmartScreen will
therefore show an unknown publisher warning when you run the downloaded .exe.
You can verify that your download matches the original build by checking its SHA-256 hash.
Heimdall3D-1.0.11-setup.exe · 124 MB
a70fccabcf5be8a3ba3a766c6a5097a9d59791dd1982d37804611acdd61c79e5
Heimdall3D-1.0.11.zip · 142 MB
4c4b0dcf0a76ff39e7f10451557fc1a35ef3c945c062797fc81de1e382e1b402
Run this command in PowerShell:
Get-FileHash <file> -Algorithm SHA256
The result must match the hash shown above. Do not run the file if it does not.
Credits
Every picture on this page is a render of somebody else's model. Three of them are licensed under Creative Commons Attribution, where the credit is a condition of use.
- “Stained Glass Lamp” © 2021 Wayfair (Eric Chadwick), CC BY 4.0.
- “Anisotropy Barn Lamp” © 2023 Wayfair, LLC (Eric Chadwick), CC BY 4.0.
- “Mosquito In Amber” © 2018 Loic Norgeot / Sketchfab, real-time refraction © 2019 Sketchfab, CC BY 4.0.
The rest are CC0 and require no credit. They are named because the people who made them did the work: the brass goblets and the bronze whale by Tina, the chandelier by Kirill Sannikov, and the classic laptop by Arrangemonk, all from Poly Haven. The sci-fi helmet and the flight helmet come from the Khronos glTF Sample Assets.
The woman in the sprite sheet is Renderpeople's rp_sophia_animated_003. Their terms permit rendering their people for advertising, and forbid passing the 3D data on, which is why the sheet is here and the model is not.
The light in every render is a Poly Haven HDRI, and the floors are from Poly Haven and ambientCG. The mannequin that plays a motion capture clip is Quaternius's Universal Animation Library 2. The toolbar glyphs are Tabler Icons, MIT.
Full credits, with the source and the licence for each.
The mailing list
One message goes out when a new build is released.
There are no newsletters, promotions or unrelated messages, and your address is not shared with anyone else.
Every message includes an unsubscribe link. Open it, press one button, and you are removed from the list.
Questions
Why do my 3D models show as blank icons in Windows Explorer?
Windows has no built-in thumbnail support for most 3D formats. Microsoft's 3D Viewer covered a few and has been removed from new installations. Heimdall3D adds a thumbnail handler that renders glTF, GLB, VRM, FBX, OBJ, PLY, COLLADA, 3DS, 3MF, STL and BVH files directly, so the file list shows the model instead of a generic page icon. It uses its own renderer and does not depend on any Microsoft component.
Can Windows Explorer preview EXR and HDR files?
Not on its own. With Heimdall3D installed, EXR, Radiance HDR, PIC, PFM, DDS, KTX2, Basis and TIFF files get real thumbnails and open in the Explorer preview pane with exposure control in EV stops, tone-mapping options, gamma and channel isolation. The image is decoded in floating point, so raising the exposure recovers detail rather than stretching an already flattened picture.
Can I rotate a model in the Explorer preview pane?
Yes. The preview pane is an interactive viewer, not a still. You can orbit the camera, zoom, change the environment map and the floor, and play any animation the file carries. It is the same viewer that ships in the Heimdall3D plugin for Directory Opus, running in the same window with the same controls.
Will installing it break the thumbnails another program already provides?
No. Where a file type already has a thumbnail handler from another application, the previous one is recorded before ours is registered and put back when Heimdall3D is uninstalled. A repeat install or an upgrade does not overwrite that record with our own handler, which is the case most likely to lose it.
Why does a .gltf file with separate textures not open in the preview pane?
Windows gives a preview handler the contents of the selected file and never tells it where the file lives, so nothing stored beside it can be found. A .gltf that keeps its geometry in a .bin file, or its textures as separate images, therefore cannot be assembled inside the pane. Use .glb, which carries everything in one file, or double-click to open the model in the viewer window, which has the path and no such limit.
Do I need Directory Opus?
No. The Explorer thumbnails, the preview pane and the viewer window all work on a plain Windows installation. If the installer finds Directory Opus on the machine it adds the Opus plugin as well, because it is the same viewer and the same version, but nothing requires it.