Oculus Rift

Feedback on past, current, and future development.
User avatar
AnyOldName3
Posts: 2666
Joined: 26 Nov 2015, 03:25

Re: Oculus Rift

Post by AnyOldName3 »

My understanding was that the GPLv3 allowed you to compile against closed-source libraries provided they weren't shipped with the software (otherwise, how would you compile against DirectX?). That would mean we could use OpenVR and then let users who actually own a VR headset download OpenVR's binaries separately without any licences being violated.
User avatar
psi29a
Posts: 5355
Joined: 29 Sep 2011, 10:13
Location: Belgium
Gitlab profile: https://gitlab.com/psi29a/
Contact:

Re: Oculus Rift

Post by psi29a »

AnyOldName3 wrote:My understanding was that the GPLv3 allowed you to compile against closed-source libraries provided they weren't shipped with the software (otherwise, how would you compile against DirectX?). That would mean we could use OpenVR and then let users who actually own a VR headset download OpenVR's binaries separately without any licences being violated.
Yes, you can provide a 'plugin' type interface to work-around the wording of the license. This is how winamp and other media players work.

We, OpenMW, just can't ship it as apart of OpenMW.
User avatar
Br0ken
Posts: 243
Joined: 02 Apr 2012, 05:54
Location: Siberia

Re: Oculus Rift

Post by Br0ken »

Quote from GNU GPL FAQ:
Both versions of the GPL have an exception to their copyleft, commonly called the system library exception. If the GPL-incompatible libraries you want to use meet the criteria for a system library, then you don't have to do anything special to use them; the requirement to distribute source code for the whole program does not include those libraries, even if you distribute a linked executable containing them.

The criteria for what counts as a "system library" vary between different versions of the GPL. GPLv3 explicitly defines "System Libraries" in section 1, to exclude it from the definition of "Corresponding Source." GPLv2 deals with this issue slightly differently, near the end of section 3.
User avatar
Okulo
Posts: 672
Joined: 05 Feb 2012, 16:11

Re: Oculus Rift

Post by Okulo »

Lagahan wrote:FB/OVR pumped money into these guys because they were very skeptical of it ever taking off, just like how Sony is also pumping money into the PSVR exclusives. I'd say after the ecosystem and all the SDKs settle we'll see multi-headset compatible ones.
If they want VR to take off, pumping money into it is a good idea, but exclusives is not. Have an advertising contract with developers, fine. But it's not unreasonable to expect a company that claims to work towards the best VR for consumers to reject the concept of exclusives.
lethality
Posts: 5
Joined: 14 Jul 2016, 12:46

Re: Oculus Rift

Post by lethality »

I used OsgOpenVRViewer to get OpenMW rendering to my Vive but there is obviously a lot of work to do to get it working right. My understanding is that the licence will be OK because OsgOpenVRViewer and the OpenVR SDK are both 3 clause BSD but it would be great if anyone else can provide some clarity on that.

Has anyone else done any work on VR support? I am totally unfamiliar with OpenMW and OSG and any kind of VR development and I don't even have a whole lot of experience with C++ so I'm not starting with much.

https://github.com/ChrisDenham/osgopenvrviewer
https://github.com/ValveSoftware/openvr
aesylwinn
Posts: 243
Joined: 14 Dec 2015, 20:30

Re: Oculus Rift

Post by aesylwinn »

From what I understand, OpenVR is incompatible with the GPL because it requires linking to steam's closed source implementation. Perhaps someone else has a better grasp of the situation though.

An alternative is OSVR, but that library is still under development.

Edit: Looks like I restated what the previous posts stated. They also mention a potential workaround, which is essentially creating a dummy library you can dynamically link to at runtime. That probably isn't a beginner friendly solution though.
lethality
Posts: 5
Joined: 14 Jul 2016, 12:46

Re: Oculus Rift

Post by lethality »

The OpenVR binary files are downloaded automatically when you set up the Vive so we wouldn't need to distribute them. I'm obviously not suggesting any type of implementation that would mean users require OpenVR in order to run OpenMW, a dummy library might have some practical use in that respect.

Nothing will run on the Vive without using steam's proprietary software at some point, OSVR uses SteamVR to support the Vive. Not allowing people to modify the software to run on their particular hardware seems like exactly the type of restriction that the GPL was designed to prevent.

I was more interested in whether anyone was working on any form of VR support or has any ideas about what type of changes would be required. It seems most of the work will be getting OpenMW to use the input from the controllers and headset, that input should be basically the same regardless of which interface is used. Different hardware might provide more or less input but you have to start somewhere and I only have a Vive.

I was kind of surprised at how little interest there seems to be in this at the moment anyway, I guess I'll just keep working on it myself for now.
User avatar
Lagahan
Posts: 47
Joined: 16 Aug 2014, 11:24
Location: Ireland

Re: Oculus Rift

Post by Lagahan »

The biggest issue back when this topic was started was the non interpolated physics movement that would've caused judder and also the performance issues. I think the engine is at the point where it runs well enough now for VR though, however it would require the water shader being turned off as instead of rendering everything twice for stereo it would effectively be 4 times.Water shader still reks AMD drivers as well. Perhaps a Vulkan render sometime in the future would sort that out tho!

Another thing is that race height would need to be disregarded entirely to match the players actual physical height for immersion. The UI would need to be rendered onto a flat plane object in 3D space as well to be usable in VR.

There's definitely interest out there, everyone is hungry for more VR titles at the moment!
User avatar
Br0ken
Posts: 243
Joined: 02 Apr 2012, 05:54
Location: Siberia

Re: Oculus Rift

Post by Br0ken »

User avatar
scrawl
Posts: 2152
Joined: 18 Feb 2012, 11:51

Re: Oculus Rift

Post by scrawl »

There are some problems with the stereo mode in OpenSceneGraph missing very basic but essential features, like setting projection and view matrices per camera. I hope to prepare a patch soon for OSG to solve these issues
Pretty sure that's doing it wrong. How about using the ComputeStereoMatrices callback?
Post Reply