3D Object preview (3mf, fbx, glb, gltf, obj, ply, stl)

Directory Opus 12.10 will add support for a new type of viewer that comes with newer versions of Windows 10, enabling you to use the Mixed Reality Viewer in the preview pane for various types of 3D object files:

  • .3mf
  • .fbx
  • .glb
  • .gltf
  • .obj
  • .ply
  • .stl

The objects can be rotated by dragging with the mouse, and zoom in and out using the mouse wheel.

Demo video on YouTube:

This update will be free to existing Opus 12 users. You'll need a recent version of Windows 10, else you won't have the Mixed Reality Viewer needed to display this type of file (unless you have an alternative compatible viewer installed).

The viewer should work automatically for these file types, provided you're using Opus 12.10 and a recent version of Windows 10. (I think the Windows 10 Creators Update should be enough, but have only tested with the later April 2018 "1803" update.)

Note that the viewer's capabilities are down to what the Mixed Reality Viewer component in Windows provides in the form of its viewer. What we're adding to Opus is the ability to work with this new type of viewer.


Above updated to note that .3mf also works, however it seems to be limited to .3mf files created by Microsoft's own tools.

Unlike the other formats, none of the third party .3mf samples I found on the web work.

But the .3mf files that come with Windows, in the /profile/3D Objects folder, load OK and let you rotate them in 3D:

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Hi, could you add support for Lightwave .lwo files please?

it comes in two flavours - lwo for 2015 (lwo2) and lwo for 2018 (lwo3)


lwo2 is most prevalent, lwo3 is the latest with new features but both are needed as files can be in either depending on source.

Another nice one would be the Modo .lxo format, which is based on the original .lwo format:



We can't, unless Lightwave or someone else provides a viewer component for their 3D object format.

any chance to get a Cinema 4d file preview ? There is a win_thumbnail.dll that allows once registered to see the scene as an icon within opus already. Is that dll enough or has Maxon to provide something more/else ?

Does Opus show the same thing as File Explorer, or does Explorer show more? If it's the same then it's probably not something we can add easily.

looks as it is the same

the differences are because these things need to be kind of rendered and I just activated this icon view again. Opus shows same now

Hello Leo,
Could you elaborate on what you mean by "an alternative compatible viewer"? I'm one of those cavemen who's still trying to invent the wheel using Windows 7 and would love to have this functionality in Directory Opus. Hope there's an alternative way of doing 3d in a viewer as you seem to suggest.
On a related node: it would also be great to view Blender files (*.blend) like this. Blender is open source and I'm sure the required API(?) is out there...
Ok, have a great day!

Does a glbt format really exist? Should it not be gltf?

Quite right. Fixed.

same question as broflodge ..

Im on win 8.1 on my workstation and theres no mixed reality viewer .. i have asutodesk fbx viewer installed though ..

The Opus viewer pane supports these things:

  • The preview handler API (as used in File Explorer and Outlook). This is what the Windows 10 Mixed Reality Viewer uses.
  • General ActiveX controls (as used in Internet Explorer; if they are registered correctly for the filetype involved).
  • Viewers written for Opus's own API.
  • Code internal to Opus (not relevant here, but handles things like JPG, BMP, etc.).
  • The shell thumbnail and icon APIs (only good for static images).
  • Via the MultiView plugin, the Oracle OutsideIn viewers.
  • Image decoding via WIC (via a hardcoded list of formats, but easy to change).
  • (Maybe some other types I've forgotten, but they probably wouldn't be relevant here.)

Whether 3D object viewers exist in any of those formats for older versions of Windows, I don't know. It's not something I use.

If a vendor wants to provide this kind of viewer, and they've actively updating their software, then they'll most likely provide it as a preview handler, since that's what works with File Explorer. Older software sometimes included viewers in the form of ActiveX controls so you could view things in IE, but as IE is fading away there are fewer and fewer people doing that.

I have some problem with that viewer. I´m trying to create gitf files and view them with opus viewer.
I succeed so far that my objects are displayed, but an animation added to them won´t play.
From the screenshot you see animation is recognized as playback option is shown, but clicking start, noching happens. Same file sent to an online viewer plays as expected. Any idea what can be wrong ?

edit - if you like to investigate, I could upload a simple sample file as well.

That screenshot isn't from Opus or even the Opus viewer window hosting a 3rd party component. It looks like a program completely unrelated to Opus. You need to ask on the forum or support channel for whatever that is to get help using it.

intersting, this is what I get if I doubleclick a gitf file within opus....
So how can I force opus to use it´s own viewer ?
edit: if I check VST plugins section here, it says viewer comes with windows, so that´s what windows is presenting me ?


that is the mixed reality viewer .. the same window is loaded (apparently) when you show the opus preview plane but embedded instead of autonomous ...
the preview plane will update whe you SINGLE click a file , double clicking obviously opens the file in the assigned program (which is the mixed reality viewer in your case)

Ah, I see . So that thing does not seem to support animations ?
I see the object with a single click in opus preview window now with a turntable animation - not showing object animation itself . As soon as I click to it to change view, this animation is terminated as well...
Do you know another 3d viewer that will support animations and can be installed with win 10 64 bit ?

FWIW the Mixed Reality Viewer used to support animations in at least some formats, but this stopped in the last Windows update. I'm not sure if it's intentional or something they broke. (It's hard to tell with Windows updates lately.)

thanks, that explains a lot. I just have been puzzled as I´m new to that stuff that if I upload my files to this site https://gltf-viewer.donmccurdy.com/ my created files animate but if I try to open them with opus which is more convenient of course, they don´t.
Strange thing though, if I open the files provided with that windows viewer - their animation is fine and working ....

Is anyone currently getting this to work with windows 10 for objs and stls? For objs, the Directory Opus previewer is just showing me a list of vertexes. Stls are just showing up as the .stl icon instead of a model preview. I'm using windows version 1803, which meets Directory Opus's file requirements as far as I can tell. My Windows version does come with 3d Viewer (you mention "Mixed Reality Viewer"? in the description above) but I'm not seeing how to integrate that viewer into DOpus's explorer-replacement window. I'm unable to figure out how to get the functionality shown here in this video. Tips?